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Why do I get so anxious after drinking? Here’s the science behind ‘hangxiety’

<a href="https://theconversation.com/profiles/blair-aitken-1510537">Blair Aitken</a>, <a href="https://theconversation.com/institutions/swinburne-university-of-technology-767">Swinburne University of Technology</a> and <a href="https://theconversation.com/profiles/rebecca-rothman-2231560">Rebecca Rothman</a>, <a href="https://theconversation.com/institutions/swinburne-university-of-technology-767">Swinburne University of Technology</a> You had a great night out, but the next morning, anxiety hits: your heart races, and you replay every conversation from the night before in your head. This feeling, known as hangover anxiety or “<a href="https://adf.org.au/insights/what-is-hangxiety/">hangxiety</a>”, <a href="https://onlinelibrary.wiley.com/doi/10.1002/hup.2623">affects around 22%</a> of social drinkers. While for some people, it’s mild nerves, for others, it’s a wave of anxiety that feels impossible to ride out. The “Sunday scaries” may make you feel panicked, filled with dread and unable to relax. Hangover anxiety can make even simple tasks feel overwhelming. Here’s why it happens, and what you can do about it. <h2>What does alcohol do to our brains?</h2> A hangover is the body’s way of recovering after drinking alcohol, bringing with it a range of symptoms. <a href="https://www.mdpi.com/2077-0383/10/23/5691">Dehydration and disrupted sleep</a> play a large part in the pounding headaches and nausea many of us know too well after a big night out. But hangovers aren’t just physical – there’s a strong mental side too. Alcohol is a nervous system depressant, meaning it alters how certain chemical messengers (or neurotransmitters) behave in the brain. Alcohol relaxes you by increasing <a href="https://my.clevelandclinic.org/health/articles/22857-gamma-aminobutyric-acid-gaba">gamma-aminobutyric acid</a> (GABA), the neurotransmitter that makes you feel calm and lowers inhibitions. It decreases <a href="https://my.clevelandclinic.org/health/articles/22839-glutamate">glutamate</a> and this also slows down your thoughts and helps ease you into a more relaxed state. Together, this interaction affects your mood, emotions and alertness. This is why when we drink, we often feel more sociable, carefree and willing to let our guard down. As the effects of the alcohol wear off, your brain works to rebalance these chemicals by <a href="https://www.sciencedirect.com/science/article/pii/S0191886918305762">reducing GABA and increasing glutamate</a>. This shift has the opposite effect of the night before, causing your brain to become more excitable and overstimulated, which can lead to feelings of anxiety. So why do some people get hangxiety, while others don’t? There isn’t one clear answer to this question, as several factors can play a role in whether someone experiences hangover-related anxiety. <h2>Genes play a role</h2> For some, a hangover is simply a matter of how much they drank or how hydrated they are. But genetics may also play a significant role. <a href="https://onlinelibrary.wiley.com/doi/10.1111/add.12699">Research</a> shows your genes can explain almost half the reason why you wake up feeling hungover, while your friend might not. Because genes influence how your body processes alcohol, some people may experience more intense hangover symptoms, such as headaches or dehydration. These stronger physical effects can, in turn, <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1002/hup.2623">trigger anxiety during a hangover</a>, making you more susceptible to “hangxiety.” <h2>Do you remember what you said last night?</h2> But one of the most common culprits for feeling anxious the next day is often <a href="https://journals.sagepub.com/doi/pdf/10.1177/0091450915604988">what you do while drinking</a>. Let’s say you’ve had a big night out and you can’t quite recall a conversation you had or something you did. Maybe you acted in ways that you now regret or feel embarrassed about. You might fixate on these thoughts and get trapped in a cycle of worrying and rumination. This cycle can be hard to break and can make you feel more anxious. <a href="https://doi.org/10.1016/j.addbeh.2023.107619">Research</a> suggests people who already struggle with feelings of anxiety in their day-to-day lives are especially vulnerable to hangxiety. Some people drink alcohol to unwind after a stressful day or to make themselves feel more comfortable at social events. This often leads to <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC9756407">heavier consumption</a>, which can make hangover symptoms more severe. It can also begin a cycle of drinking to feel better, making hangxiety even harder to escape. <h2>Preventing hangover anxiety</h2> The best way to prevent hangxiety is to limit your alcohol consumption. The <a href="https://adf.org.au/reducing-risk/alcohol/alcohol-guidelines">Australian guidelines</a> recommend having no more than ten standard drinks per week and no more than four standard drinks on any one day. Generally, the more you drink, the more intense your hangover symptoms might be, and the worse you are likely to feel. Mixing other drugs with alcohol can also increase the risk of hangxiety. This is especially true for party drugs, such as ecstasy or MDMA, that give you a temporary high but can lead to anxiety as they wear off and you are <a href="https://adf.org.au/insights/drug-comedowns">coming down</a>. If you do wake up feeling anxious: <ul> <li> focus on the physical recovery to help ease the mental strain </li> <li> drink plenty of water, eat a light meal and allow yourself time to rest </li> <li> try <a href="https://www.headspace.com/mindfulness/mindfulness-101">mindfulness meditation</a> or deep breathing exercises, especially if anxiety keeps you awake or your mind races </li> <li> consider journalling. This can help re-frame anxious thoughts, put your feelings into perspective and encourage self-compassion </li> <li> talk to a close friend. This can provide a safe space to express concerns and feel less isolated. </li> </ul> Hangxiety is an unwelcome guest after a night out. Understanding why hangxiety happens – and how you can manage it – can make the morning after a little less daunting, and help keep those anxious thoughts at bay.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/240991/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/blair-aitken-1510537">Blair Aitken</a>, Postdoctoral Research Fellow in Psychopharmacology, <a href="https://theconversation.com/institutions/swinburne-university-of-technology-767">Swinburne University of Technology</a> and <a href="https://theconversation.com/profiles/rebecca-rothman-2231560">Rebecca Rothman</a>, PhD Candidate in Clinical Psychology, School of Health Sciences, <a href="https://theconversation.com/institutions/swinburne-university-of-technology-767">Swinburne University of Technology</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/why-do-i-get-so-anxious-after-drinking-heres-the-science-behind-hangxiety-240991">original article</a>.

Mind

What is ‘doll therapy’ for people with dementia? And is it backed by science?

<a href="https://theconversation.com/profiles/nikki-anne-wilson-342631">Nikki-Anne Wilson</a>, <a href="https://theconversation.com/institutions/unsw-sydney-1414">UNSW Sydney</a> The way people living with dementia <a href="https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/how-dementia-changes-perception">experience the world</a> can change as the disease progresses. Their sense of reality or place in time can become distorted, which can cause <a href="https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/symptoms/restlessness">agitation and distress</a>. One of the best ways to support people experiencing changes in perception and behaviour is to <a href="https://www.dementia.org.au/professionals/designing-dementia-friendly-care-environments">manage their environment</a>. This can have profound benefits including <a href="https://www.agedcarequality.gov.au/resource-library/reducing-use-sedatives-aged-care-video">reducing the need for sedatives</a>. One such strategy is the use of dolls as comfort aids. <h2>What is ‘doll therapy’?</h2> More appropriately referred to as “<a href="https://www.dementia.com.au/resource-hub/the-use-of-dolls-in-dementia-care">child representation</a>”, lifelike dolls (also known as empathy dolls) can provide comfort for some people with dementia. Memories from the <a href="https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/symptoms/memory-loss#:%7E:text=Older%20memories%20%E2%80%93%20which%20have%20been,detailed%20memories%20from%20earlier%20life.">distant past</a> are often more salient than more recent events in dementia. This means that past experiences of parenthood and caring for young children may feel more “real” to a person with dementia than where they are now. <a href="https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/hallucinations#:%7E:text=Visual%20hallucinations%20are%20more%20common,hallucinating%20and%20how%20others%20respond.">Hallucinations or delusions</a> may also occur, where a person hears a baby crying or fears they have lost their baby. Providing a doll can be a tangible way of reducing distress without invalidating the experience of the person with dementia. <h2>Some people believe the doll is real</h2> A recent case involving <a href="https://www.theguardian.com/australia-news/2024/nov/06/deplorable-nurse-slammed-therapy-doll-dementia-patient-believed-was-real-baby-on-table-nsw-tribunal-hears">an aged care nurse mistreating a dementia patient’s therapy doll</a> highlights the importance of appropriate training and support for care workers in this area. For those who do become attached to a therapeutic doll, they will treat the doll as a real baby needing care and may therefore have a profound emotional response if the doll is mishandled. It’s important to be guided by the person with dementia and only act as if it’s a real baby if the person themselves believes that is the case. <h2>What does the evidence say about their use?</h2> Evidence shows the use of empathy dolls may help <a href="https://www.sciencedirect.com/science/article/pii/S0197457223002677">reduce agitation and anxiety</a> and <a href="https://www.mdpi.com/2039-4403/14/4/200">improve overall quality of life</a> in people living with dementia. Child representation therapy falls under the banner of <a href="https://www.sciencedirect.com/science/article/pii/S0149763423004761">non-pharmacological approaches to dementia care</a>. More specifically, the attachment to the doll may act as a form of <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC6494367/">reminiscence therapy</a>, which involves using prompts to reconnect with past experiences. Interacting with the dolls may also act as a form of <a href="https://www.health.vic.gov.au/dementia-friendly-environments/sensory-stimulation">sensory stimulation</a>, where the person with dementia may gain comfort from touching and holding the doll. Sensory stimulation may <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/jocn.13169?casa_token=ro96fxe2VPoAAAAA%3AKOS10VkTdcrf0yTI_F9p6cI5Kpbj85ZTFq13PQ56YHxi0i3-5BOnFQfW1WFWqiCZ8-mk5sp_EGkGtKM">support emotional well-being and aid commnication</a>. However, not all people living with dementia will respond to an empathy doll. The <a href="https://www.alzheimerswa.org.au/wp-content/uploads/2017/07/2.00-Guidlines-for-Use-of-Dolls-and-Mechanized-Pets-as-a-Therapeutic-Tool-4-pages.pdf">introduction of a therapeutic doll</a> needs to be done in conjunction with careful observation and consideration of the person’s background. Empathy dolls may be inappropriate or less effective for those who have not previously cared for children or who may have experienced past birth trauma or the loss of a child. Be guided by the person with dementia and how they respond to the doll. <h2>Are there downsides?</h2> The approach has <a href="https://pubmed.ncbi.nlm.nih.gov/33125455/">attracted some controversy</a>. It has been suggested that child representation therapy “infantilises” people living with dementia and may increase negative stigma. Further, the attachment may become so strong that the person with dementia will <a href="https://www.dementiauk.org/information-and-support/living-with-dementia/doll-therapy/">become upset if someone else picks the doll up</a>. This may create some difficulties in the presence of grandchildren or when cleaning the doll. The introduction of child representation therapy may also require additional staff training and time. Non-pharmacological interventions such as child representation, however, have been shown to be <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC10180718/">cost-effective</a>. <h2>Could robots be the future?</h2> The use of more <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC8247474/#:%7E:text=Therefore%2C%20an%20interactive%20baby%20robot,mental%20support%20for%20older%20adults.">interactive empathy dolls</a> and <a href="https://journals.sagepub.com/doi/full/10.1177/14713012231155985">pet-like robots</a> is also gaining popularity. While robots have been shown to be <a href="https://www.sciencedirect.com/science/article/pii/S1568163722000757">feasible and acceptable in dementia care</a>, there remains some contention about their benefits. While some studies have shown <a href="https://academic.oup.com/innovateage/article/5/2/igab013/6249558?login=false">positive outcomes</a>, including reduced agitation, others show <a href="https://www.sciencedirect.com/science/article/pii/S1568163722000757">no improvement</a> in cognition, behaviour or quality of life among people with dementia. Advances in artificial intelligence are also being used to help support people living with dementia and <a href="https://journals.sagepub.com/doi/full/10.1177/1471301221998888">inform</a> the community. <a href="https://feel-lab.org/research_projects/ai-viv-and-friends/">Viv and Friends</a>, for example, are AI companions who appear on a screen and can interact with the person with dementia in real time. The AI character Viv has dementia and was co-created with women living with dementia using verbatim scripts of their words, insights and experiences. While Viv can share her experience of living with dementia, she can also be programmed to talk about common interests, such as gardening. These companions are currently being trialled in some residential aged care facilities and to help educate people on the lived experience of dementia. <h2>How should you respond to your loved one’s empathy doll?</h2> While child representation can be a useful adjunct in dementia care, it requires sensitivity and appropriate consideration of the person’s needs. People living with dementia <a href="https://pubmed.ncbi.nlm.nih.gov/38325063/">may not perceive the social world the same way</a> as a person without dementia. But a person living with dementia is not a child and should never be treated as one. Ensure all family, friends and care workers are <a href="https://www.alzheimerswa.org.au/wp-content/uploads/2017/07/2.00-Guidlines-for-Use-of-Dolls-and-Mechanized-Pets-as-a-Therapeutic-Tool-4-pages.pdf">informed about the attachment to the empathy doll</a> to help avoid unintentionally causing distress from inappropriate handling of the doll. If using an interactive doll, ensure spare batteries are on hand. Finally, it is important to reassess the attachment over time as the person’s response to the empathy doll may change.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/243589/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/nikki-anne-wilson-342631">Nikki-Anne Wilson</a>, Postdoctoral Research Fellow, Neuroscience Research Australia (NeuRA), <a href="https://theconversation.com/institutions/unsw-sydney-1414">UNSW Sydney</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/what-is-doll-therapy-for-people-with-dementia-and-is-it-backed-by-science-243589">original article</a>.

Mind

The science of the ideal salad dressing

<a href="https://theconversation.com/profiles/nathan-kilah-599082">Nathan Kilah</a>, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a> Summer means salads. And salads are even more delicious with a good dressing. Most salad dressings are temporarily stable mixtures of oil and water known as emulsions. But how do salad dressing emulsions form? And how can we enhance our emulsions for better salads and more? <h2>Oil and water don’t mix</h2> It’s accepted wisdom that oil and water don’t mix. The water and oil molecules have distinct chemical properties that don’t interact well together. You may have seen this if you’ve attempted to make a salad dressing by shaking together oil and vinegar (which is mostly water), which gives a temporary suspension that quickly separates. There is a large energy cost to breaking apart and mixing the water and oil layers. The secret to blending them together is to add an extra ingredient known as a “surfactant” or emulsifier. The name surfactant is derived from “surface active”. It highlights that these molecules work at the surface or interface to bridge the interactions between the oil and water. This is similar to how <a href="https://theconversation.com/what-is-sodium-lauryl-sulfate-and-is-it-safe-to-use-125129">detergents</a> are able to remove grease from your dishes. Many vinaigrette recipes call for emulsifiers without specifically mentioning their crucial emulsifying role. Key examples are mustard and garlic, which contain “mucilage” – a mix of carbohydrates – that can act as emulsifiers. So if your vinegar/oil salad dressings are separating, make sure you’re adding enough of these ingredients (which also contain <a href="https://theconversation.com/hate-vegetables-you-might-have-super-taster-genes-74428">wonderful flavour chemicals</a>). Commercial salad dressings also contain naturally sourced emulsifying carbohydrates. These will often be listed on the ingredients as generic “vegetable gum” or similar, and you may need to <a href="https://theconversation.com/busting-the-myth-that-all-food-additives-are-bad-a-quick-guide-for-label-readers-82883">read the label</a> and delve a little deeper into the <a href="https://www.foodstandards.gov.au/consumer/additives/additiveoverview/Documents/Food%20Additive%20Code%20Numbers%20%28July%202014%29.pdf">food additive number</a> to find out the source. Researchers have raised questions about <a href="https://theconversation.com/food-additives-and-chronic-disease-risk-what-role-do-emulsifiers-play-38492">synthetic emulsifiers used in processed food</a>, as studies in mice suggest they have health risks. It’s too early to say exactly what this means for humans. <h2>Shake it ‘til you make it</h2> Mixing is key to dispersing oil in water. While shaking a jar is convenient, a whisk or food processor will give a more complete emulsion. The white (or opaque) colour of many emulsions is due to the formation of microdroplets that scatter light. These mechanical mixing methods are even more essential for the formation of so-called “permanent emulsions” such as mayonnaise. Mayonnaise is an emulsion of oil in water, but egg yolk is the key emulsifier. Egg yolks contain long molecules called <a href="https://link.springer.com/referenceworkentry/10.1007/978-3-642-36605-5_28">phospholipids</a> that are able to interact with both the oil layer and the water. Mayonnaise is an impressively stable emulsion, which is why is can be sold in a shelf-stable form. But it isn’t infinitely stable; heating the mayonnaise emulsion will cause it to split. Perhaps you’ve hurriedly prepared a potato salad and added a mayonnaise-based dressing before the potatoes have cooled down? Or toasted a sandwich spread with mayonnaise? (Incidentally, adding mayonnaise to the outside of a toasted sandwich is an excellent path to some <a href="https://theconversation.com/kitchen-science-from-sizzling-brisket-to-fresh-baked-bread-the-chemical-reaction-that-makes-our-favourite-foods-taste-so-good-58577">delicious and crispy chemical reactions</a>.) The heat destabilises the emulsion and the separate oil and water phases will reform. Depending on the mixture, split emulsions may be recovered by adding more emulsifier and re-whisking or re-mixing. Hollandaise sauce is a notoriously difficult emulsion to prepare. The traditional hollandaise method involves whisking egg yolk, water, and lemon juice over a low heat, then slowly adding melted butter with further whisking. Not only can the emulsion split, but you can also overcook the added emulsifying egg yolk. The key to a successful hollandaise emulsion is separating the butter into fine, dispersed droplets, giving a thick and opaque mixture, but without cooking the eggs. Adding the butter too quickly or without sufficient mixing can give a split sauce. Using an <a href="https://www.seriouseats.com/foolproof-2-minute-hollandaise-recipe">immersion blender</a> can help, as can controlling the temperature of the melted butter. You might get a more consistently emulsified sauce with far less strain on your wrists. <h2>You’ve got me feeling emulsions</h2> Emulsions are used in many more places than salads and sauces. Most medicated creams, cosmetics and lotions are emulsions of oils and water, which is why they look white. Gardeners might be familiar with a mixture known as “<a href="https://www.abc.net.au/gardening/how-to/horticultural-oils/9428876">white oil</a>” – a mixture of vegetable oil and detergent. This brew, when diluted in water, is an inexpensive, effective, yet mild insecticide. Commercial versions often contain other pesticides, so make sure you read the label. Modern <a href="https://www.acs.org/education/whatischemistry/landmarks/acrylicemulsion.html">acrylic paints use emulsions</a> for both their manufacturing and application. The emulsions suspend the paint polymers in a water base. The water from the paint evaporates, leaving a film of paint polymers that can’t be re-dispersed into water. This clever chemical trick has saved huge quantities of oil-derived solvents from being used, <a href="https://theconversation.com/why-solvents-can-affect-brain-health-even-at-low-levels-of-exposure-98081">inhaled</a>, and emitted into the environment from traditional oil-based paints. Modern vaccines use <a href="https://theconversation.com/adjuvants-the-unsung-heroes-of-vaccines-156548">emulsions to increase the immune systems response</a>. Other common emulsions are inks, <a href="https://theconversation.com/how-does-ice-cream-work-a-chemist-explains-why-you-cant-just-freeze-cream-and-expect-results-205038">ice cream</a>, margarine and hair products, to name just a few. So next time you’re making a salad, check your emulsions. Opposites don’t attract, but mixing them with the right chemistry can give a delicious result.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/216159/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/nathan-kilah-599082">Nathan Kilah</a>, Senior Lecturer in Chemistry, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/the-science-of-the-ideal-salad-dressing-216159">original article</a>.

Food & Wine

The Science of Sound: How Innovation and Nutrition Can Enhance Your Hearing

To help his hearing-impaired wife, Hans Demant founded Oticon in 1904. Since then, <a href="https://www.oticon.co.nz/hearing-aid-users" target="_blank" rel="noopener">Oticon’s</a> legacy of care and cutting-edge technology has been transforming the experience of sound for 120 years. In real life, environments vary – some noisy, some quiet, some with speech, some without. But what you want to hear depends on your intentions, which could change in a moment. <a href="https://www.oticon.co.nz/hearing-aid-users/hearing-aids/products/intent" target="_blank" rel="noopener">Oticon Intent</a>TM hearing aids are built to detect your listening intentions^ and provide personalised hearing support in any situation*. So, you can focus on sounds that matter and access the world around you. To do this, Oticon Intent is powered by 4D Sensor technology* and a full-time second-generation Deep Neural Network (DNN) that has learned from experience. <img class="alignnone size-full wp-image-51713" src="https://oversixtydev.blob.core.windows.net/media/2024/10/Demant_History_Acousticon_Coronation_Device_1910_Model_RD_1908_Intent_120years_wide_1280.jpg" alt="" width="1280" height="533" /> Today’s ground-breaking Oticon Intent alongside an historic “Acousticon” from 1910. Some hearing solutions are complex; others are incredibly simple. While it’s important to protect our ears against ear infections and loud noises, did you know diet can play a role in preventing age-related hearing loss?1 <ul> <li>Foods rich in omega-3 fatty acids and Vitamin D, like tuna, can benefit the cardiovascular system and reduce inflammation that may damage sensitive ear tissue2.</li> <li>Foods containing antioxidants and folic acid, like spinach, may reduce risk of hearing loss by up to 20% by improving inner ear blood flow3.</li> <li>Fruit and veg rich in Vitamins C and E can strengthen the immune system, protecting blood vessels and nerves around the ears to help prevent infections.</li> </ul> By working nutrient-rich foods into your diet, you can help safeguard your hearing health for years to come. To help celebrate Oticon’s incredible 120-year milestone, we’re giving away a $400 Prezzee Gift Card! Using the information in this article, simply <a href="https://www.readersdigest.co.nz/contests/oticon-intent-120th-anniversary-giveaway" target="_blank" rel="noopener">answer the contest questions online</a> for your chance to win. For more information visit <a href="http://www.oticon.co.nz/oticon-intent" target="_blank" rel="noopener">www.oticon.co.nz/oticon-intent</a>, and to find your nearest <a href="https://www.oticon.co.nz/hearing-aid-users/find-audiologist" target="_blank" rel="noopener">hearing centre</a> visit <a href="https://www.oticon.co.nz/" target="_blank" rel="noopener">oticon.co.nz</a>. This is a sponsored article produced in partnership with Oticon. ^4D Sensor Technology only available in Oticon Intent 1 & 2. #Bianchi/Eskelund et al. (2024). Oticon IntentTM – Clinical evidence. BrainHearingTM benefits of the 4D Sensor technology. Oticon whitepaper. Sponsored by Oticon. <sup1Rodrigo, L., Campos-Asensio, C., Rodríguez, M., Crespo, I., & Olmedillas, H. (2021). Role of nutrition in the development and prevention of age-related hearing loss: A scoping review, 2021, Science Direct. 2Calder, P., Omega-3 Fatty Acids and Inflammatory Processes, 32010,National Library of medicine. Curhan, S. et al, Fish and fatty acid consumption and the risk of hearing loss in women, 2014.

Hearing

The science of happier dogs: 5 tips to help your canine friends live their best life

<a href="https://theconversation.com/profiles/mia-cobb-15211">Mia Cobb</a>, <a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</a> When you hear about “science focused on how dogs can live their best lives with us” it sounds like an imaginary job made up by a child. However, the field of <a href="https://www.rnz.co.nz/podcast/ourchangingworld?share=2ec8e0ad-5008-4b2d-ae2e-a288e2a77f50">animal welfare science is real</a> and influential. As our most popular animal companion and coworker, dogs are very deserving of scientific attention. In recent years we’ve learned more about <a href="https://theconversation.com/dogs-can-get-dementia-but-lots-of-walks-may-lower-the-risk-189297">how dogs are similar to people</a>, but also how they are distinctly themselves. We often think about how dogs help us – as companions, <a href="https://theconversation.com/meet-moss-the-detection-dog-helping-tassie-devils-find-love-142909">working as detectors</a>, and keeping us <a href="https://theconversation.com/is-owning-a-dog-good-for-your-health-238888">safe and healthy</a>. Dog-centric science helps us <a href="https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.666898/full">think about the world from a four-paw perspective</a> and apply this new knowledge so dogs can enjoy a good life. Here are five tips to keep the tails in your life wagging happily. <h2>1. Let dogs sniff</h2> Sniffing <a href="https://www.psychologytoday.com/intl/blog/animal-emotions/201902/allowing-dogs-sniff-helps-them-think-positively">makes dogs happier</a>. We tend to forget they live in a smell-based world because we’re so visual. Often taking the dog for a walk is our daily physical activity but we should remember it could be our dogs’ only time out of the home environment. Letting them have a really good sniff of that tree or post is full of satisfying information for them. It’s their nose’s equivalent of us standing at the top of a mountain and enjoying a rich, colour-soaked, sunset view. <h2>2. Give dogs agency</h2> Agency is a <a href="https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1284869/full">hot topic in animal welfare science</a> right now. For people who lived through the frustration of strict lockdowns in the early years of COVID, it’s easy to remember how not being able to go where we wanted, or see who we wanted, when we wanted, impacted our mental health. We’ve now learned that <a href="https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1250251/full">giving animals choice and control</a> in their lives is important for their mental wellbeing too. We can help our dogs enjoy better welfare by creating more choices and offering them control to exercise their agency. This might be installing a doggy door so they can go outside or inside when they like. It could be letting them decide which sniffy path to take through your local park. Perhaps it’s choosing which three toys to play with that day from a larger collection that gets rotated around. Maybe it’s putting an old blanket down in a new location where you’ve noticed the sun hits the floor for them to relax on. Providing choices doesn’t have to be complicated or expensive. <h2>3. Recognise all dogs are individuals</h2> People commonly ascribe certain personality traits to certain dog breeds. But just like us, dogs have their own personalities <a href="https://scitechdaily.com/food-vs-toys-scientists-reveal-what-dogs-truly-prefer/">and preferences</a>. Not all dogs are going to like the same things and a new dog we live with may be completely different to the last one. One dog might like to go to the dog park and run around with other dogs at high speed for an hour, while another dog would much rather hang out with you chewing on something in the garden. We can see as much <a href="https://www.science.org/content/article/your-dog-s-breed-doesn-t-determine-its-personality-study-suggests">behavioural variation within breeds as we do between them</a>. Being prepared to meet dogs where they are, as individuals, is important to their welfare. As well as noticing what dogs like to do as individuals, it’s important not to force dogs into situations they don’t enjoy. <a href="https://www.rspca.org.uk/adviceandwelfare/pets/dogs/behaviour/understanding">Pay attention to behaviour</a> that indicates dogs aren’t comfortable, such as looking away, licking their lips or yawning. <h2>4. Respect dogs’ choice to opt out</h2> Even in our homes, we can provide options if our dogs don’t want to share in every activity with us. Having a quiet place that dogs can retreat to is really important in enabling them to opt out if they want to. If you’re watching television loudly, it may be too much for <a href="https://www.psychologytoday.com/au/blog/canine-corner/202407/how-good-is-a-dogs-hearing-compared-to-humans">their sensitive ears</a>. Ensure a door is open to another room so they can retreat. Some dogs might feel overwhelmed when visitors come over; giving them somewhere safe and quiet to go rather than forcing an interaction will help them cope. Dogs can be terrific role models for children when teaching empathy. We can demonstrate consent by letting dogs approach us for pats and depart when they want. Like seeing exotic animals perform in circuses, dressing up dogs for our own entertainment seems to have had its day. If you asked most dogs, they don’t want to wear costumes or be part of your Halloween adventures. <h2>5. Opportunities for off-lead activity – safely.</h2> When dogs are allowed to run off-lead, they use space differently. They tend to explore more widely and go faster than they do when walking with us on-lead. This offers them important and fun physical activity to keep them fit and healthy. <figure><iframe src="https://www.youtube.com/embed/2AchEFiDwA8?wmode=transparent&start=0" width="440" height="260" frameborder="0" allowfullscreen="allowfullscreen"></iframe><figcaption>Demonstrating how dogs walk differently when on- and off-lead.</figcaption></figure> A recent exploration of <a href="https://pursuit.unimelb.edu.au/articles/we-checked-if-melbourne-really-is-a-dog-friendly-city">how liveable cities are for dogs</a> mapped all the designated areas for dogs to run off-leash. Doggy density ranged from one dog for every six people to one dog for every 30 people, depending on where you live. It also considered how access to these areas related to the annual registration fees for dogs in each government area compared, with surprising differences noted across greater Melbourne. We noted fees varied between A$37 and $84, and these didn’t relate to how many off-lead areas you could access. For dog-loving nations, such as Australia, helping our canine friends live their best life feels good. <a href="https://www.rnz.co.nz/national/programmes/afternoons/audio/2018957756/our-changing-world-the-science-behind-dog-welfare">Science that comes from a four-paw perspective</a> can help us reconsider our everyday interactions with dogs and influence positive changes so we can live well, together.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/236952/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/mia-cobb-15211">Mia Cobb</a>, Research Fellow, Animal Welfare Science Centre, <a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/the-science-of-happier-dogs-5-tips-to-help-your-canine-friends-live-their-best-life-236952">original article</a>.

Family & Pets

Ozempic, Wegovy, Rybelsus: Are we losing sight of overall health? Here’s what the science says

<a href="https://theconversation.com/profiles/aude-bandini-1488512">Aude Bandini</a>, <a href="https://theconversation.com/institutions/universite-de-montreal-1743">Université de Montréal</a>; <a href="https://theconversation.com/profiles/jean-philippe-drouin-chartier-1533338">Jean-Philippe Drouin-Chartier</a>, <a href="https://theconversation.com/institutions/universite-laval-1407">Université Laval</a>; <a href="https://theconversation.com/profiles/pierre-marie-david-1375228">Pierre-Marie David</a>, <a href="https://theconversation.com/institutions/universite-de-montreal-1743">Université de Montréal</a>, and <a href="https://theconversation.com/profiles/remi-rabasa-lhoret-1533515">Rémi Rabasa-Lhoret</a>, <a href="https://theconversation.com/institutions/universite-de-montreal-1743">Université de Montréal</a> The craze for new drugs in the GLP-1 (Glucagon-like peptide 1) and GIP (Gastric inhibitory polypeptide) analogue class, better known under the trade names Ozempic and Wegovy, is remarkable, but it’s not totally unprecedented in the history of pharmaceutical blockbusters. The volume of prescriptions and the budget allocated to them by public health insurance schemes are exploding, as are the <a href="https://www.forbes.com/sites/roberthart/2024/05/02/ozempic-maker-novo-nordisk-beats-profit-forecasts-amid-weight-loss-drug-frenzy/">profits of the companies that manufacture them</a>. Part of the popularity of these drugs owes to social networks, but these are not always the best source for health information. When it comes to the subject of weight loss, both fantasy and prejudice come into play. This works to the detriment of everyone’s well-being, but particularly those who are already stigmatized. As specialists in the philosophy of medicine (Université de Montréal), nutrition and food science (Université Laval), the sociology of medication (Université de Montréal) and endocrinology (Institut de recherches cliniques de Montréal), we feel it’s necessary to step back and take stock of both the promises and the limitations of these new treatments. <h2>The best of both worlds</h2> GLP-1/GIP analogues were originally developed to regulate glycemia (blood sugar levels) in people with Type 2 diabetes, thereby preventing the complications associated with this disease. When studies were carried out to assess their safety and efficacy, it was discovered that these drugs also led to weight loss. This prompted new research which showed that at higher doses, the drugs could lead to <a href="https://pubmed.ncbi.nlm.nih.gov/38078870/">very significant weight loss</a>, from 15 to 25 per cent of the starting weight. The mode of action of these drugs on blood sugar regulation is clear: they simulate incretin hormones which, in turn, increase insulin secretion. Weight loss, on the other hand, was only explained after the fact: in addition to the pancreas, these molecules also act on the brain by regulating the sensation of satiety and, indirectly, on the stomach by slowing gastric emptying. These two combined effects reduce appetite and lead to weight reduction. This is how a new use for the drug appeared, at which point the company Novo Nordisk began marketing the same drug under two different names: Ozempic to treat Type 2 diabetes, and <a href="https://theconversation.com/considering-taking-wegovy-to-lose-weight-here-are-the-risks-and-benefits-and-how-it-differs-from-ozempic-237308">Wegovy to manage obesity</a>. <h2>A new era</h2> GLP-1/GIP analogues are a welcome therapeutic breakthrough at a time when the <a href="https://www.diabetes.ca/advocacy---policies/advocacy-reports/national-and-provincial-backgrounders/diabetes-in-canada">prevalence of Type 2 diabetes</a> and <a href="https://www.statcan.gc.ca/o1/en/plus/5742-overview-weight-and-height-measurements-world-obesity-day">obesity</a> is exploding and affecting people younger and younger. These diseases particularly affect women, members of racialized groups and socio-economically disadvantaged populations. The physical and mental suffering these cause and the costs associated with treating them are both considerable. So the arrival of new weapons in the therapeutic arsenal is a source of hope. Draconian changes in lifestyle are certainly effective. But they are very difficult to implement and maintain over time for reasons that go beyond the individual sphere; on the one hand, genetic predisposition plays a major role in the development of Type 2 diabetes and obesity; on the other, because these conditions are <a href="https://obesitycanada.ca/managing-obesity/">multifactorial</a>, management of them must be comprehensive to be effective and long lasting: it must combine medical interventions but also nutritional, functional, psycho-social, environmental and even institutional interventions. Support services of this kind do exist, but only in large university hospital centres to which many people do not have access. Nor do many people have easy access to <a href="https://health-infobase.canada.ca/health-inequalities/index">healthy and varied food options</a>, sports facilities or social and psychological support. <h2>Treating the effects but not the causes</h2> To be effective over the long term, GLP-1/GIP analogues must be taken continuously: without drastic lifestyle changes, the <a href="https://pubmed.ncbi.nlm.nih.gov/35441470/">weight that was lost is regained within a year of stopping</a>, and glycemic control is compromised once again. In other words, the drugs treat the effects of Type 2 diabetes and obesity but not their causes. And yet some of these causes are modifiable: for example, according to <a href="https://www150.statcan.gc.ca/n1/pub/75-006-x/2023001/article/00013-eng.htm">Statistics Canada</a>, less than half the Canadian population (49.2 per cent for adults; 43.9 per cent for young people and children) achieves the recommended amount of weekly physical activity. According to the same source, <a href="https://www150.statcan.gc.ca/n1/pub/75-006-x/2023001/article/00013-eng.htm">food insecurity</a> affects around 14 per cent of the Québec population (22 per cent in Alberta). Pharmacological treatment, even if it allows an individual to eat less, does not necessarily mean that person will <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10837702/">eat better</a>. Similarly, losing weight does not mean one will become more active or healthier. So these new drugs do not cure Type 2 diabetes or obesity. Nor do they prevent these diseases from developing, although they do help to limit the many complications to which they give rise. <h2>Prescribe and treat</h2> A drug such as Mounjaro is as effective at weight loss as bariatric surgery. Much easier to administer and much less risky, it could be a real game changer in the treatment of obesity. Prescribed directly by family doctors and dispensed in pharmacies, it would also be much more accessible and easier to administer for those who need it. This raises the question of costs and reimbursement, but not only that: prescribing is not the same as treating. Here, the manufacturers are following the recommendations of the health authorities: this treatment must be preceded by a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10748770/">careful assessment</a>, then management, and above all a close and regular monitoring of diet, physical activity, mental health, and if necessary, socio-economic assistance. This requires not only time that GPs do not have, but also co-ordination with other players in the health-care network. The problem is not whether the treatment will be effective, but what can happen if it is. Losing 25 per cent of your body weight in just a few months has serious consequences, which are not always beneficial: it involves a loss of body fat, but also of muscle mass, which is associated with intense fatigue. Nor should we underestimate the <a href="https://pubmed.ncbi.nlm.nih.gov/37990685/">challenge of adapting physically and psychologically</a> to a body transformation of this scale. Losing weight doesn’t solve everything, and expectations must remain realistic. <h2>What lessons can we learn?</h2> The clinical effectiveness of GLP-1/GIP analogues in reducing the complications associated with Type 2 diabetes and obesity is indisputable. However, these drugs are not suitable for everyone, and they are certainly not miracle cures that will make it possible for one to regain health without making any changes to lifestyle or environment. We must bear in mind that their success, both commercial and medical, is also the result of a failure: that of our societies to prevent these diseases, to promote healthy lifestyles and to develop environments conducive to the health of all.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/238484/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/aude-bandini-1488512">Aude Bandini</a>, Professeure agrégée, Philosophie (épistémologie et philosophie de la médecine), <a href="https://theconversation.com/institutions/universite-de-montreal-1743">Université de Montréal</a>; <a href="https://theconversation.com/profiles/jean-philippe-drouin-chartier-1533338">Jean-Philippe Drouin-Chartier</a>, Professeur agrégé, Faculté de pharmacie, <a href="https://theconversation.com/institutions/universite-laval-1407">Université Laval</a>; <a href="https://theconversation.com/profiles/pierre-marie-david-1375228">Pierre-Marie David</a>, Professeur adjoint à la faculté de pharmacie, <a href="https://theconversation.com/institutions/universite-de-montreal-1743">Université de Montréal</a>, and <a href="https://theconversation.com/profiles/remi-rabasa-lhoret-1533515">Rémi Rabasa-Lhoret</a>, Professeur de médecine et de nutrition, <a href="https://theconversation.com/institutions/universite-de-montreal-1743">Université de Montréal</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/ozempic-wegovy-rybelsus-are-we-losing-sight-of-overall-health-heres-what-the-science-says-238484">original article</a>.

Body

MSG is back. Is the idea it’s bad for us just a myth or food science?

<a href="https://theconversation.com/profiles/evangeline-mantzioris-153250">Evangeline Mantzioris</a>, <a href="https://theconversation.com/institutions/university-of-south-australia-1180">University of South Australia</a> MSG is making a comeback. The internet’s favourite cucumber salad recipe includes fish sauce, cucumber, garlic and – as the video’s creator Logan tells us with a generous sprinkle from the bag – “MSG, obviously”. But for many of us, it’s not obvious. Do you have a vague sense MSG is unhealthy but you’re not sure why? Here is the science behind monosodium glutamate, how it got a bad rap, and whether you should add it to your cooking. <h2>What is MSG?</h2> Monosodium glutamate (MSG) is a sodium salt of glutamic acid, one of the amino acids that make up proteins. It occurs naturally in <a href="https://www.tandfonline.com/doi/full/10.1080/10942912.2017.1295260#d1e167">foods</a> such as mature cheeses, fish, beef, mushrooms, tomatoes, onion and garlic. It provides their savoury and “meaty” flavour, known as <a href="https://www.sciencedirect.com/science/article/pii/S0022316622140186">umami</a>. MSG has been used to season food for <a href="https://wjpsonline.com/index.php/wjps/article/view/effects-monosodium-glutamate-human-health-review">more than 100 years</a>. Traditionally it <a href="https://pubs.acs.org/doi/epdf/10.1021/ed081p347?ref=article_openPDF">was extracted</a> from seaweed broth, but now it’s made by fermenting starch in sugar beets, sugar cane and molasses. Today it’s widely used as a flavour enhancer in many dishes and pre-packaged goods, including soups, condiments and processed meats. There is no chemical difference between the MSG found in food and the additive. <h2>Is it safe?</h2> For most people, yes. MSG is a safe and authorised additive, according to the Australian agency that regulates food. This corresponds with food standards in the <a href="https://www.fda.gov/food/food-additives-petitions/questions-and-answers-monosodium-glutamate-msg">United States</a>, <a href="https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02008R1333-20201223#tocId3">European Union and United Kingdom</a>. Two major <a href="https://www.foodstandards.gov.au/sites/default/files/consumer/additives/msg/Documents/MSG%20Technical%20Report.pdf">safety reviews</a> have been conducted: one in 1987 by a United Nations expert committee and another 1995 by the Federation of American Societies for Experimental Biology. Both concluded MSG was safe for the general population. In 2017 the <a href="https://www.efsa.europa.eu/en/efsajournal/pub/4910">European Food Safety Authority</a> updated its stance and set a recommended limit based on body weight, aimed to prevent headaches and increased blood pressure. That limit is still higher than most people consume. The authority says an 80kg person should not have more than 2.4g of added MSG per day. <a href="https://www.nature.com/articles/1602526">For reference</a>, Europeans average less than a gram per day (0.3-1 gram), while in Asia intake is somewhere between 1.2-1.7 grams a day. Food Standards Australia New Zealand says the European update does not raise any new safety concerns not already assessed. <h2>Isn’t it bad for me?</h2> Despite the evidence, the idea MSG is dangerous persists. Its notorious reputation can be traced back to a <a href="https://news.colgate.edu/magazine/2019/02/06/the-strange-case-of-dr-ho-man-kwok/">hoax letter</a> published in the <a href="https://www.nejm.org/doi/full/10.1056/NEJM196805162782014">New England Journal of Medicine</a> in 1968. A doctor claiming to have experienced palpitations, numbness and fatigue after eating at a Chinese restaurant suggested MSG could be to blame. With a follow-up article in the <a href="https://www.nytimes.com/1968/05/19/archives/-chinese-restaurant-syndrome-puzzles-doctors.html">New York Times</a>, the idea of “Chinese Restaurant Syndrome” took off. Eating MSG was associated with a range of symptoms, including headache, hives, throat swelling, itching and belly pain. However an <a href="https://www.sciencedirect.com/science/article/pii/027869159390012N?via%3Dihub">early randomised control trial</a> showed no difference in these symptoms between people who were given MSG versus a placebo. This has since been confirmed in a <a href="https://ift.onlinelibrary.wiley.com/doi/full/10.1111/1541-4337.12448">review of many studies</a>. <h2>Can MSG cause reactions?</h2> A very small percentage of people may have hypersensitivities to MSG. The reported reaction is now known as MSG symptom complex, rather than so-called Chinese restaurant syndrome, with its <a href="https://www.jandonline.org/article/S2212-2672(21)00068-X/abstract#:%7E:text=A%20New%20York%20Times%20piece,connecting%20MSG%20to%20health%20outcomes.">problematic</a> racial connotations. Symptoms are usually mild, short-term and don’t need treatment. <a href="https://www.sciencedirect.com/science/article/pii/S0091674999703714">One study</a> looked at 100 people with asthma, 30 of whom believed they had hypersensitivities to MSG. However when participants were blinded to whether they were consuming MSG, not one reported a reaction. If you believe you do react to added MSG, it’s relatively easy to avoid. In Australia, it is <a href="https://www.foodstandards.gov.au/consumer/additives/msg">listed</a> in ingredients as either monosodium glutamate or flavour enhancer 621. <h2>Is it better than table salt?</h2> Using MSG instead of regular salt may help <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6893472/">reduce</a> your overall sodium intake, as MSG <a href="https://www.medicalnewstoday.com/articles/msg-what-the-science-says-about-its-safety#Uses-of-MSG">contains</a> about one third the amount of sodium. <a href="https://pubmed.ncbi.nlm.nih.gov/21372742/">One study</a> found people who ate soup seasoned with MSG rather than salt actually liked it more. They still found it salty to taste, but their sodium intake was reduced by 18%. MSG still contains sodium, so high use is associated with increased <a href="https://pubmed.ncbi.nlm.nih.gov/21372742/">blood pressure</a>. If you’re using MSG as a substitute and you have high blood pressure, you should closely monitor it (just as you would with other salt products). <h2>Should I use MSG in my cooking?</h2> If you want to – yes. Unless you are one of the rare people with hypersensitivities, enhancing the flavour of your dish with a sprinkle of MSG will not cause any health problems. It could even help reduce how much salt you use. If you’re <a href="https://www.tandfonline.com/doi/full/10.1080/25765299.2020.1807084#d1e199">vegetarian or vegan</a>, cooking with MSG could help add the umami flavour you may miss from animal products such as meat, fish sauce and cheese. But buying foods with added MSG? Be aware, many of them will also be <a href="https://www.cambridge.org/core/journals/public-health-nutrition/article/un-decade-of-nutrition-the-nova-food-classification-and-the-trouble-with-ultraprocessing/2A9776922A28F8F757BDA32C3266AC2A">ultra-processed</a> and it’s that – not the MSG – that’s associated with poor physical and mental <a href="https://www.mdpi.com/2072-6643/14/1/174">health outcomes</a>.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/237871/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/evangeline-mantzioris-153250">Evangeline Mantzioris</a>, Program Director of Nutrition and Food Sciences, Accredited Practising Dietitian, <a href="https://theconversation.com/institutions/university-of-south-australia-1180">University of South Australia</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/msg-is-back-is-the-idea-its-bad-for-us-just-a-myth-or-food-science-237871">original article</a>.

Food & Wine

Do mobile phones cause brain cancer? Science makes definitive call

The question of whether mobile phones - specifically the electromagnetic radiation or radio waves emitted by these devices - cause cancer has been debated and researched for a long time, and now scientists have made a definitive call. A new comprehensive review commissioned by the World Health Organization has found that mobile phones are NOT linked to brain and head cancers. The systematic review, led by the Australian Radiation Protection and Nuclear Safety Agency (Arpansa), examined over 5,000 studies, which included 63 observational studies on humans published between 1994 and 2022 and is "the most comprehensive review to date" according to review lead author, associate prof Ken Karipidis. “We concluded the evidence does not show a link between mobile phones and brain cancer or other head and neck cancers," he said. The review, which was published on Wednesday, focused on cancers of the nervous system, salivary gland and brain tumours. They found no overall association between mobile phone use and cancer, even if people have used it for a long time (over 10 years) or spend a lot of time on their phones. “I’m quite confident with our conclusion. And what makes us quite confident is … even though mobile phone use has skyrocketed, brain tumour rates have remained stable,” Karipidis continued. Despite emitting electromagnetic radiation, also known as radio waves, the exposure is relatively low. Karipidis said people hear the word radiation and assume it is similar to nuclear radiation, “and because we use a mobile phone close to the head when we’re making calls, there is a lot of concern.” He clarified that “radiation is basically energy that travels from one point to another. There are many different types, for example, ultraviolet radiation from the sun." “We’re always exposed to low-level radio waves in the everyday environment.” While exposure from mobile phones is still low, it is much higher than exposure from any other wireless technology sources since they are used close to the head, Karipidis said. The association between mobile phones and cancers came about from early studies comparing differences between those with and without brain tumours and asking about their exposure history. According to Karipidis, who is also the vice-chair of the International Commission on Non-Ionizing Radiation Protection, the results from these kind of studies tend to be biased, as the group with the tumour tend to overreport their exposure. Based on these early studies WHO’s International Agency for Research on Cancer (IARC) designated radio-frequency fields like those from mobile phones as a possible cancer risk, but Karipidis said "this classification doesn’t mean all that much”. This is because the IARC has different classifications of cancer risk, with some substances classified as a “definite” carcinogen (such as smoking), and others as “probable” or “possible” carcinogens. Tim Driscoll, a professor at the University of Sydney and chair of the Australian Cancer Council’s occupational and environmental cancers committee, also backed the systematic review. “I think people should feel reassured by this study … but it’s worthwhile just remembering that the studies aren’t perfect, but the weight of evidence certainly is that mobile phones should be considered safe to use in terms of any concerns about increased risk of cancer,” Driscoll said. Images: Shutterstock

Body

Can a 10-year-old be responsible for a crime? Here’s what brain science tells us

<a href="https://theconversation.com/profiles/susan-m-sawyer-109573">Susan M. Sawyer</a>, <a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</a> and <a href="https://theconversation.com/profiles/nandi-vijayakumar-1644262">Nandi Vijayakumar</a>, <a href="https://theconversation.com/institutions/deakin-university-757">Deakin University</a> The age a child can be arrested, charged and jailed in Australia is back in the spotlight. Last year, the Northern Territory became the first jurisdiction to raise the age of criminal responsibility from ten to 12. Now its new, tough-on-crime government has pledged to <a href="https://www.sbs.com.au/nitv/article/incoming-chief-minister-says-age-of-criminal-responsibility-to-be-lowered-to-10-years-old/a1xm9jy9c">return it to ten</a>. It comes after Victoria <a href="https://www.abc.net.au/news/2024-08-13/victoria-youth-justice-reform-criminal-age/104217160">walked back</a> its earlier commitment to raise the age to 14, settling instead on 12. But the United Nations Committee on the Rights of the Child says 14 should be the absolute <a href="https://www.ohchr.org/en/documents/general-comments-and-recommendations/general-comment-no-24-2019-childrens-rights-child">minimum</a>. It raised this age from its earlier recommendation (in 2007) of 12, citing a decade of new research into child and adolescent development. So what does the science say? What happens to the brain between ten and 14? And how much can those under 14 understand the consequences of their actions? <h2>Who is an adolescent?</h2> Our research shows adolescence is a <a href="https://pubmed.ncbi.nlm.nih.gov/30169257/">critical period</a> for development. It’s the time children’s experiences and explorations shape how they develop cognitive skills (including critical thinking and decision making), as well as social and emotional skills (including moral reasoning). Adolescence also lasts longer than we tend to think. Important brain development begins during late childhood, around eight to nine years. Intense changes then follow during early adolescence (ages ten to 14). But these changes continue well into the twenties, and full cognitive and emotional maturity is not usually reached until around age 24. However, everyone’s brain matures at a different rate. That means there is no definitive age we can say humans reach “adult” levels of cognitive maturity. What we do know is the period of early adolescence is critical. <h2>What does puberty do to the brain?</h2> Puberty is a defining feature of early adolescence. Most of us are familiar with the changes that occur to the body and reproductive systems. But the increase in puberty hormones, such as testosterone and oestrogen, also trigger changes to the brain. These hormones <a href="https://www.sciencedirect.com/science/article/abs/pii/S0306453017313252?via%3Dihub">increase most sharply</a> between ten and 15 years of age, although gradual changes continue into the early twenties. Puberty hormones change the structures in the brain which process emotions, including the amygdala (which encodes fear and stress) and ventral striatum (involved in reward and motivation). This makes adolescents particularly reactive to emotional rewards and threats. <a href="https://doi.org/10.1016/j.cortex.2019.04.024">Our research</a> has shown the brain’s sensitivity to emotions increases throughout early adolescence until around 14 or 15 years old. At the same time, changes in puberty have <a href="http://dx.doi.org/10.1037/pspp0000172">been linked</a> to increased sensation seeking and impulsive behaviours during early adolescence. This context is crucial when we discuss the behaviour of children in the ten to 14 age range. The way their brains change during this period makes them more sensitive and responsive to emotions, and more likely to be seeking experiences that are new and intense. <h2>How do adolescents make decisions?</h2> The emotional context of puberty influences how younger adolescents make decisions and understand their consequences. Decision making relies on several basic cognitive functions, including the brain’s flexibility, memory and ability to control impulses. These cognitive abilities – which together help us consider the consequences of our actions – undergo some of the <a href="https://doi.org/10.1523/JNEUROSCI.1741-13.2013">steepest development</a> between ages ten and 14. By age 15, the ability to make complex decisions has usually <a href="https://doi.org/10.1037/lhb0000315">reached adult maturity</a>. But adolescents at this age remain highly susceptible to emotions. So while their brain may be equipped to make a complex decision, their ability to think through the consequences, weighing up costs and benefits, can be clouded by emotional situations. For example, <a href="https://doi.org/10.1111/cdev.12085">research has shown</a> 13-14 year-olds were more distracted from completing a task and less able to control their behaviour when they viewed images that made them feel negative emotions. The social world of teenagers also has a significant impact on how they make decisions – especially in early adolescence. One study found that while older adolescents (aged 15-18) are more influenced by what adults think when weighing up risk, adolescents aged 12-14 <a href="https://journals.sagepub.com/doi/full/10.1177/0956797615569578">look to other teenagers</a>. Experiments <a href="https://doi.org/10.1177/0272431616648453">have also shown</a> adolescents aged 12-15 make riskier decisions when they are with peers than by themselves. Their brain responses also suggest they experience a greater sense of reward in taking those risks <a href="https://doi.org/10.1093/scan/nsy071">with peers</a>. <h2>How do teens understand the consequences of their actions?</h2> The concept of <a href="https://www.aph.gov.au/About_Parliament/Parliamentary_Departments/Parliamentary_Library/pubs/rp/rp2122/Quick_Guides/MinimumAgeCriminalResponsibility">criminal responsibility</a> is based on whether a person is able to understand their action and know whether it is wrong. Moral reasoning – how people think about right and wrong – depends on the ability to understand another person’s mental state and adopt their perspective. These skills are in development <a href="https://doi.org/10.1016/j.biopsych.2020.09.012">across adolescence</a>. Research suggests it may take more effort for adolescent brains to process <a href="https://doi.org/10.1162/jocn.2009.21121">“social” emotions</a> such as guilt and embarrassment, compared to adults. This is similar when they make <a href="https://doi.org/10.1080/17470919.2014.933714">moral judgements</a>. This evidence suggests teenage brains may have to work harder when considering other people’s intentions and desires. Young adolescents have the cognitive ability to appreciate they made a bad decision, but it is more mentally demanding. And social rewards, emotions and the chance to experience something new all have a strong bearing on their decisions and actions in the moment — possibly more than whether it is right or wrong. <h2>Early adolescence is critical for the brain</h2> There are also a number of reasons adolescent brains may develop differently. This includes various forms of neurodisability such as acquired brain injury, fetal alcohol spectrum disorder, attention-deficit hyperactivity disorder (ADHD) and intellectual disability, as well as exposure to trauma. Teenagers with neurodevelopmental disorders will likely cope differently with decision making, social pressure, impulse control and risk assessment, and face <a href="https://www.mcri.edu.au/images/research/strategic-collaborations/Flagships/Neurodevelopment/Neurodevelopment_Flagship_Brochure.pdf">extra difficulties</a>. Across the world, they are <a href="https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(19)30217-8/fulltext">disproportionately incarcerated</a>. In Australia, Indigenous children and adolescents are incarcerated <a href="https://www.indigenoushpf.gov.au/measures/2-11-contact-with-the-criminal-justice-system#:%7E:text=On%20an%20average%20day%20in%202021%E2%80%9322%2C%20there%20were%3A,AIHW%202023d%3A%20Table%20S76a">in greater numbers</a> than their non-Indigenous peers. Each child matures differently, and some face extra challenges. But for every person, the period between ten and 14 is critical for developing the cognitive, social and emotional skills they’ll carry through the rest of their life.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/237552/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/susan-m-sawyer-109573">Susan M. Sawyer</a>, Professor of Adolescent Health The University of Melbourne; Director, Royal Children's Hospital Centre for Adolescent Health, <a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</a> and <a href="https://theconversation.com/profiles/nandi-vijayakumar-1644262">Nandi Vijayakumar</a>, Research Fellow, School of Psychology, <a href="https://theconversation.com/institutions/deakin-university-757">Deakin University</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/can-a-10-year-old-be-responsible-for-a-crime-heres-what-brain-science-tells-us-237552">original article</a>.

Mind

Anti-cellulite products are big business – but here’s what the science says

<div class="theconversation-article-body"><a href="https://theconversation.com/profiles/rebecca-shepherd-423135">Rebecca Shepherd</a>, <a href="https://theconversation.com/institutions/university-of-bristol-1211">University of Bristol</a> Although <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/jocd.14815">90% of women have cellulite</a>, we’re yet to see it represented as a normal anatomical characteristic in popular culture. In Greta Gerwig’s 2023 Hollywood blockbuster, for instance, Stereotypical Barbie, played by Margot Robbie, develops dimples on her upper thigh as part of her existential crisis – along with other human faults such as halitosis, flat feet and irrepressible thoughts of death. When Stereotypical Barbie asks doll sage Weird Barbie what the dimples are, she explains: “That’s cellulite. That’s going to spread everywhere. Then you’re going to start getting sad and mushy and complicated.” Barbie’s perfect smooth plastic perfection is marred. Despite its prevalence, then, cellulite has been constructed as a flaw in need of correction. Consumers, it seems, agree, especially when fed a diet of the <a href="https://www.tandfonline.com/doi/full/10.1080/21604851.2021.1913827">photoshop smoothed skin</a> of models, social media influencers – and Hollywood stars. <figure><iframe src="https://www.youtube.com/embed/rmThigh1i8s?wmode=transparent&start=0" width="440" height="260" frameborder="0" allowfullscreen="allowfullscreen"></iframe><figcaption>“NO!” Barbie shouts when Weird Barbie tells her she has cellulite.</figcaption></figure> Cellulite’s usually found in areas that have greater amounts of subcutaneous fat, when fat deposits push through the connective tissue beneath the skin, leading to a lumpy appearance. It is common, <a href="https://www.sciencedirect.com/science/article/pii/S0738081X1300076X?via%3Dihub">usually painless</a> and harmless. The human skin is the <a href="https://theconversation.com/the-skin-is-a-very-important-and-our-largest-organ-what-does-it-do-91515">body’s largest organ</a>, made up of three layers. At the surface, the epidermis acts as our first line of defence against the environment. This outermost, impermeable layer is made up of cells that are constantly renewed and shed, protecting our body from external elements. Beneath the epidermis lies the dermis, a robust layer containing fibroblasts, the cells responsible for producing essential proteins such as collagen and elastin. These proteins provide structure and elasticity, contributing to the skin’s strength and flexibility. Deeper still is the hypodermis, also known as the subcutaneous layer. This layer is rich in adipose tissue – mostly made up of fat, which plays a crucial role in cushioning and insulating the body, as well as storing fat that can be used when needed. Beneath these three layers of skin, there is muscle. Running from the muscle to the dermis are <a href="https://journals.lww.com/amjdermatopathology/fulltext/2000/02000/cellulite__from_standing_fat_herniation_to.7.aspx">bands of connective tissue</a>, that holds the adipose tissue in “pockets”. Cellulite does not affect health, although some people report that it affects their <a href="https://www.tandfonline.com/doi/abs/10.1080/07853890.2018.1561731">self-esteem and body image</a> but that’s more to do with the social pressure on women to be physically perfect – or spend money, time and energy trying to be as close to perfect as possible. Cellulite, then, has become big business for the beauty industry. In the lead up to summer especially, companies will promote <a href="https://www.asa.org.uk/advice-online/weight-control-cellulite.html">all manner of products</a> from creams and serums to gadgets and pills, all aimed at creating perfectly smooth limbs. The most popular question seems to be, “Do these treatments work?” but as an anatomist I think the more pressing question is, “Why are healthy women’s bodies considered something to treat, cure or correct?” The beauty and wellness industry has long capitalised on societal standards of beauty. The idea that cellulite is undesirable and <a href="https://journals.lww.com/dermatologicsurgery/abstract/1978/03000/So_Called_Cellulite.9.aspx">should be corrected</a> has been perpetuated since Vogue magazine was the <a href="https://archive.vogue.com/article/1968/4/cellulite-the-new-word-for-fat-you-couldnt-lose-before">first English language magazine</a> to use the term “cellulite”, introducing the concept to thousands of women. This marketing strategy taps into the insecurities of consumers, particularly women, and promotes an endless pursuit of “perfection” for bodies that have normal anatomical variation. By framing cellulite as a condition that needs treatment, companies can sell a wide range of products and services, bolstered by celebrity endorsements, which lend credibility and aspirational value to pseudo-medical “smoothing” products. However, there is limited scientific evidence supporting the effectiveness of these supplements in treating cellulite. In fact, the <a href="https://onlinelibrary.wiley.com/doi/10.1111/j.1524-4725.1978.tb00416.x">first scientific paper</a> on cellulite, published in 1978, referred to it as “so called cellulite: the invented disease”. Recent product launches include, <a href="https://lemmelive.com/en-gb/products/lemme-smooth-capsules?variant=45597048111318">Lemme Smooth</a>, Kourtney Kardashian-Barker’s latest addition to her vitamin and supplement range. The product’s promotional materials claim that the capsule “visibly reduces cellulite in 28 days”. But what does the science tell us? Supplements like Lemme Smooth claim to improve skin texture and reduce cellulite from within. Kardashian-Barker’s supplement contains a mixture of <a href="https://link.springer.com/article/10.1007/s10298-015-0977-4">french cantaloupe melon</a>, hyaluronic acid, chromium and vitamin C among other ingredients. The body’s ability to absorb and utilise these ingredients in a way that would impact cellulite is still a subject of debate. There is evidence that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4110621/#:%7E:text=In%20a%20randomized%2C%20double%2Dblind,in%20part%2C%20to%20the%20skin.">ingested hyaluronic acid</a> can migrate into the skin, stimulating the production of collagens within the dermis – and vitamin C has been shown to <a href="https://www.nature.com/articles/s41598-020-72704-1">thicken the surface layer</a> of the skin. However, the lack of standardisation in testing for the use of these ingredients in the treatment of cellulite means it’s still not clear if they will have a <a href="https://onlinelibrary.wiley.com/doi/10.1111/j.1467-2494.2006.00318.x">significant effect</a>. Other products marketed to reduce the appearance of cellulite include topical creams and lotions, containing ingredients like <a href="https://karger.com/books/book/763/chapter-abstract/5600478/Specific-Use-Cosmeceuticals-for-Body-Skin-Texture?redirectedFrom=fulltext">caffeine, retinol, and herbal extracts</a>. Cosmetic products are not able to penetrate the epidermis enough to significantly affect the underlying fat deposits and connective tissue. Some invasive treatments, such as <a href="https://www.aad.org/public/cosmetic/fat-removal/cellulite-treatments-what-really-works">laser therapy, subcision, and acoustic wave therapy</a> can offer more promising results. These procedures work by breaking down the connective tissue bands that cause dimpling and stimulating collagen production in the dermis to improve skin elasticity. While these methods <a href="https://www.aad.org/public/cosmetic/fat-removal/cellulite-treatments-what-really-works">may be more effective</a>, they are often expensive, require multiple sessions to achieve results – and aren’t without risk. Maintaining a healthy diet, drinking lots of water, and regular physical activity can help improve the overall appearance of the skin and reduce the visibility of cellulite. Losing weight and strengthening the muscles in the legs, buttocks and abdomen may make cellulite less noticeable, but it won’t make it <a href="https://jndc-chemistryarticles.info/ijn/article/318">disappear altogether</a>. The bottom line, though, is that cellulite does not need to be treated. It’s a normal anatomical variation that’s been transformed into a condition driving a lucrative market for cures <a href="https://link.springer.com/article/10.1007/s40257-015-0129-5">that don’t exist</a>. My top expert advice in the run up to summer? Be wary of claims from cosmetic companies and save your money. <hr /> The Conversation has approached the Lemme Live brand for comment.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/232318/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/rebecca-shepherd-423135">Rebecca Shepherd</a>, Senior Lecturer in Human Anatomy, School of Anatomy, <a href="https://theconversation.com/institutions/university-of-bristol-1211">University of Bristol</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/anti-cellulite-products-are-big-business-but-heres-what-the-science-says-232318">original article</a>. </div>

Body

Michael Mosley used science communication to advance health and wellbeing. We can learn a lot from his approach

<a href="https://theconversation.com/profiles/lauren-ball-14718">Lauren Ball</a>, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a> and <a href="https://theconversation.com/profiles/kirsten-adlard-684475">Kirsten Adlard</a>, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a> Overnight, we learned of the <a href="https://www.abc.net.au/news/2024-06-09/michael-mosley-body-found-greek-island-clare-bailey-mosley/103957382">tragic passing</a> of Michael Mosley, who went missing last week while on holiday on the Greek island of Symi. The British celebrity doctor was a household name in many countries, including Australia. Mosley was well known for his television shows, documentaries, books and columns on healthy eating, weight management, physical activity and sleep. During the days he was missing and once his death was confirmed, media outlets have acknowledged Mosley’s <a href="https://www.independent.co.uk/arts-entertainment/tv/features/michael-mosley-tv-doctor-death-b2558717.html">career achievements</a>. He is being celebrated for his connection to diverse public audiences and his unrelenting focus on science as the best guide to our daily habits. <h2>From medicine to the media</h2> Mosley was born in India <a href="https://www.bbc.com/news/articles/c8770jyz6vvo">in 1957</a> and was sent to England at age seven to attend boarding school. He later studied philosophy, politics and economics at the <a href="https://michaelmosley.co.uk/biog/">University of Oxford</a>. After a short stint in investment banking, Mosley opted to train in medicine at the Royal Free Hospital in London. Rather than forging a career in clinical practice, <a href="https://michaelmosley.co.uk/biog/">Mosley</a> started working at the BBC in 1985 as a trainee assistant producer. In the decades that followed, Mosley continued to work with the BBC as a producer and presenter. Mosley became a popular public figure by applying his medical training to journalism to examine a breadth of health and wellbeing topics. In 1995, following his documentary on <a href="https://genome.ch.bbc.co.uk/baf970949e3a46a992ae52420395a7c2">Helicobacter pylori</a>, a bacterium that causes ulcers in the stomach, the British Medical Association named him <a href="https://www.bbc.co.uk/programmes/profiles/2kczjZKp8sGSDxSxKYzxsyr/michael-mosley">medical journalist of the year</a>. His other television work on diet, weight management, exercise and sleep earned him <a href="https://www.emmys.com/bios/michael-mosley">Emmy</a>, <a href="https://www.imdb.com/name/nm0608839/awards/">BAFTA</a> (the British Academy of Film and Television Arts), and <a href="https://rts.org.uk/tags/michael-mosley">Royal Television Society</a> <a href="https://www.bbc.co.uk/programmes/profiles/2kczjZKp8sGSDxSxKYzxsyr/michael-mosley">award nominations</a>. Over the past decade, Mosley published <a href="https://www.amazon.com.au/Fast-Diet-Original-Revised-Research/dp/1780722370/ref=sr_1_6?dib=eyJ2IjoiMSJ9.75_akcxo8tanyLrD4CVMwd1lCTliHyckSLPU2W7K4HmdPqRlVqvMbKWKkJ6CPCsrFsAw4Vfw5SWOYkl_Y8ah4yNCSjQksdT3ByCSHhiycNB9AB5h6vVUqB99okxDDWPaXUCwD-CZMzHZDvAjuAotTN">several books</a> on <a href="https://www.fishpond.com.au/Books/Fastexercise-Michael-Mosley-Peta-Bee-With/9781476759982?utm_source=googleps&utm_medium=ps&utm_campaign=AU&gad_source=1&gclid=CjwKCAjw34qzBhBmEiwAOUQcF3wd7d1bj8KMFeEtKS6ZU7py5rRzjiycZhcsMbSEQ9lXhjEBcY4GRxoCwgIQAvD_BwE">exercise</a>, <a href="https://www.amazon.com.au/8-Week-Blood-Sugar-Diet-Recipe/dp/1925456595/ref=sr_1_7?dib=eyJ2IjoiMSJ9.75_akcxo8tanyLrD4CVMwd1lCTliHyckSLPU2W7K4HmdPqRlVqvMbKWKkJ6CPCsrFsAw4Vfw5SWOYkl_Y8ah4yNCSjQksdT3ByCSHhiycNB9AB5h6vVUqB99okxDDWPaXUCwD-CZMzHZDvAjuAotTNxxkW3">healthy eating</a>, <a href="https://www.amazon.com.au/Fast-800-Australian-New-Zealand/dp/B07MPRQWJP/ref=sr_1_8?dib=eyJ2IjoiMSJ9.75_akcxo8tanyLrD4CVMwd1lCTliHyckSLPU2W7K4HmdPqRlVqvMbKWKkJ6CPCsrFsAw4Vfw5SWOYkl_Y8ah4yNCSjQksdT3ByCSHhiycNB9AB5h6vVUqB99okxDDWPaXUCwD-CZMzHZDvAjuAotTNxxkW">intermittent fasting</a>, <a href="https://www.amazon.com.au/Weeks-Better-Sleep-life-changing-improved/dp/1761425927/ref=sr_1_1?dib=eyJ2IjoiMSJ9.75_akcxo8tanyLrD4CVMwd1lCTliHyckSLPU2W7K4HmdPqRlVqvMbKWKkJ6CPCsrFsAw4Vfw5SWOYkl_Y8ah4yNCSjQksdT3ByCSHhiycNB9AB5h6vVUqB99okxDDWPaXUCwD-CZMzHZDvAj">sleep</a> and <a href="https://www.amazon.com.au/Just-One-Thing-Changes-Transform/dp/B0BJVRP94X/ref=sr_1_9?dib=eyJ2IjoiMSJ9.75_akcxo8tanyLrD4CVMwd1lCTliHyckSLPU2W7K4HmdPqRlVqvMbKWKkJ6CPCsrFsAw4Vfw5SWOYkl_Y8ah4yNCSjQksdT3ByCSHhiycNB9AB5h6vVUqB99okxDDWPaXUCwD-CZMzHZDvAjuAotTNxxk">behaviour change</a>. He sold millions of copies of his books around the world, including at least <a href="https://www.simonandschuster.com.au/p/mosley-1mil-sales">one million</a> in Australia and New Zealand. Alongside his wife, Dr Clare Bailey Mosley, he recently embarked on a <a href="https://michaelmosley.co.uk/live/">live theatre show tour</a>, yet another vehicle to bring his key messages to audiences. <h2>A trusted voice</h2> Mosley became a trusted voice for health and wellbeing throughout his journalistic career. His television program <a href="https://www.bbc.co.uk/programmes/b04j9gny">Trust Me, I’m a Doctor</a> drew on his medical qualifications to discuss health and wellbeing credibly on a public platform. His medical training also inferred credibility in examining the scientific literature that underpins the topics he was communicating. At the same time, Mosley used simple terminology that captured the attention of diverse audiences. For many of Mosley’s outputs, he used himself as an example. For instance, in his <a href="https://www.bbc.co.uk/programmes/p09by3yy/episodes/downloads">podcast series</a> Just One Thing and <a href="https://www.amazon.com.au/Just-One-Thing-Changes-Transform/dp/B0BJVRP94X/ref=sr_1_9?dib=eyJ2IjoiMSJ9.75_akcxo8tanyLrD4CVMwd1lCTliHyckSLPU2W7K4HmdPqRlVqvMbKWKkJ6CPCsrFsAw4Vfw5SWOYkl_Y8ah4yNCSjQksdT3ByCSHhiycNB9AB5h6vVUqB99okxDDWPaXUCwD-CZMzHZDvAjuAotTNxxk">companion book</a>, Mosley self-tested a range of evidence-based behavioural habits (while also interviewing subject-matter experts), covering topics such as eating slowly, yoga, listening to music, cooking, gardening and drinking green tea. His focus on intermittent fasting and high-intensity training was fuelled by his <a href="https://www.abc.net.au/news/2024-06-08/how-dr-michael-mosley-popularised-intermittent-fasting/103952408">diagnosis of type 2 diabetes</a>, and his work on sleep health was based on his experience <a href="https://www.sbs.com.au/food/article/sleep-revolution-michael-mosley/okmv5o7qe">with chronic insomnia</a>. At the most extreme end of the spectrum, Mosley <a href="https://www.bbc.com/news/science-environment-25968755">infested himself with tapeworms</a> in the pursuit of exploring their effects on the human body. By using himself as a <a href="https://www.theguardian.com/media/article/2024/jun/09/michael-mosley-favourite-health-tip-slow-deep-breathing">human guinea pig</a>, he fostered a connection with his audience, showing the <a href="https://www.chronicle.com/article/the-personal-touch-using-anecdotes-to-hook-a-reader">power</a> of personal anecdotes. <h2>Some controversies along the way</h2> Despite his notable career achievements, Mosley received ongoing criticisms about his work due to differing opinions within the medical and scientific communities. One key concern was around his promotion of potentially risky diets such as intermittent fasting and other restrictive diets, including the 5:2 diet and low-carb diets. While <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9946909/">some evidence</a> supports intermittent fasting as a way to improve metabolic health and enable weight management, Mosley was criticised for not fully acknowledging the potential risks of these diets, such as a potential to lead to <a href="https://clindiabetesendo.biomedcentral.com/articles/10.1186/s40842-023-00152-7">disordered eating</a> habits. His promotion of low-carb diets also raised concerns that his work added to a diet-focused <a href="https://www.independent.co.uk/life-style/health-and-families/lose-a-stone-in-21-days-channel-4-criticism-eating-disorder-food-relationship-beat-a9656531.html">culture war</a>, ultimately to the detriment of many people’s relationship with food and their bodies. More broadly, in his efforts to make scientific concepts simple and accessible to the general public, Mosley was sometimes criticised for overgeneralising science. The concern was that he didn’t properly discuss the nuance and tension inherent in scientific evidence, thereby providing an incomplete synthesis of the evidence. For example, Mosley conceptualised the <a href="https://thebloodsugardiet.com">blood sugar diet</a> (a low-carbohydrate Mediterranean-style diet), which was <a href="https://www.bbc.com/news/health-68452019">criticised</a> for lacking a strong grounding in scientific evidence. Similarly, <a href="https://www.thetimes.com/life-style/health-fitness/article/smoke-and-mirrors-the-truth-about-vaping-nmpf3przr">associating his name with e-cigarettes</a> may have drawn unhelpful attention to the topic, irrespective of the underlying details. <h2>What can we learn from Mosley?</h2> Overall, Mosley has been objectively successful in communicating scientific concepts to large, engaged audiences. Mosley showed us that people want to consume scientific information, whether through the news media, social media, podcasts or books. His passion and persistence in using science to promote health and wellbeing have likely supported public health efforts across the globe.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/231934/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/lauren-ball-14718">Lauren Ball</a>, Professor of Community Health and Wellbeing, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a> and <a href="https://theconversation.com/profiles/kirsten-adlard-684475">Kirsten Adlard</a>, Supervisor of Engagement, Communication, and Outreach, Centre for Community Health and Wellbeing, <a href="https://theconversation.com/institutions/the-university-of-queensland-805">The University of Queensland</a> Image credits: Ken McKay/ITV/Shutterstock Editorial This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/michael-mosley-used-science-communication-to-advance-health-and-wellbeing-we-can-learn-a-lot-from-his-approach-231934">original article</a>.

Caring

Are young people smarter than older adults? My research shows cognitive differences between generations are diminishing

<div class="theconversation-article-body"><a href="https://theconversation.com/profiles/stephen-badham-1531316">Stephen Badham</a>, <a href="https://theconversation.com/institutions/nottingham-trent-university-1338">Nottingham Trent University</a> We often assume young people are smarter, or at least quicker, than older people. For example, we’ve all heard that scientists, and even more so mathematicians, <a href="https://www.forbes.com/sites/nextavenue/2014/08/07/who-says-scientists-peak-by-age-50/">carry out their most important work</a> when they’re comparatively young. But my new research, <a href="https://www.sciencedirect.com/science/article/pii/S027322972400008X#:%7E:text=Highlights&text=Three%20review%20studies%20measure%20secular,%2C%20education%2C%20and%20overall%20health.">published in Developmental Review</a>, suggests that cognitive differences between the old and young are tapering off over time. This is hugely important as stereotypes about the intelligence of people in their sixties or older may be holding them back – in the workplace and beyond. Cognitive ageing is often measured by comparing young adults, aged 18-30, to older adults, aged 65 and over. There are a variety of tasks that older adults do not perform well on compared to young adults, such as memory, spatial ability and speed of processing, which often form the basis of <a href="https://theconversation.com/the-iq-test-wars-why-screening-for-intelligence-is-still-so-controversial-81428">IQ tests</a>. That said, there are a few tasks that older people do better at than younger people, such as reading comprehension and vocabulary. Declines in cognition are driven by a process called <a href="https://www.nature.com/collections/cbjacdabdf">cognitive ageing</a>, which happens to everyone. Surprisingly, age-related cognitive deficits start very early in adulthood, and declines in cognition have been measured as dropping in adults as young as just 25. Often, it is only when people reach older age that these effects add up to a noticeable amount. Common complaints consist of walking into a room and forgetting why you entered, as well as difficulty remembering names and struggling to drive in the dark. <h2>The trouble with comparison</h2> Sometimes, comparing young adults to older adults can be misleading though. The two generations were brought up in different times, with different levels of education, healthcare and nutrition. They also lead different daily lives, with some older people having lived though a world war while the youngest generation is growing up with the internet. Most of these factors favour the younger generation, and this can explain a proportion of their advantage in cognitive tasks. Indeed, much existing research shows that <a href="https://theconversation.com/iq-tests-are-humans-getting-smarter-158837">IQ has been improving</a> globally throughout the 20th century. This means that later-born generations are more cognitively able than those born earlier. This is even found when both generations are tested in the same way at the same age. Currently, there is growing evidence that <a href="https://www.pnas.org/doi/10.1073/pnas.1718793115">increases in IQ are levelling off,</a> such that, in the most recent couple of decades, young adults are no more cognitively able than young adults born shortly beforehand. Together, these factors may underlie the current result, namely that cognitive differences between young and older adults are diminishing over time. <h2>New results</h2> My research began when my team started getting strange results in our lab. We found that often the age differences we were getting between young and older adults was smaller or absent, compared to prior research from early 2000s. This prompted me to start looking at trends in age differences across the psychological literature in this area. I uncovered a variety of data that compared young and older adults from the 1960s up to the current day. I plotted this data against year of publication, and found that age deficits have been getting smaller over the last six decades. Next, I assessed if the average increases in cognitive ability over time seen across all individuals was a result that also applied to older adults specifically. Many large databases exist where groups of individuals are recruited every few years to take part in the same tests. I analysed studies using these data sets to look at older adults. I found that, just like younger people, older adults were indeed becoming more cognitively able with each cohort. But if differences are disappearing, does that mean younger people’s improvements in cognitive ability have slowed down or that older people’s have increased? I analysed data from my own laboratory that I had gathered over a seven-year period to find out. Here, I was able to dissociate the performance of the young from the performance of the older. I found that each cohort of young adults was performing to a similar extent across this seven-year period, but that older adults were showing improvements in both processing speed and vocabulary scores. <figure class="align-center "><img src="https://images.theconversation.com/files/591482/original/file-20240501-24-esxcic.png?ixlib=rb-4.1.0&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/591482/original/file-20240501-24-esxcic.png?ixlib=rb-4.1.0&q=45&auto=format&w=600&h=333&fit=crop&dpr=1 600w, https://images.theconversation.com/files/591482/original/file-20240501-24-esxcic.png?ixlib=rb-4.1.0&q=30&auto=format&w=600&h=333&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/591482/original/file-20240501-24-esxcic.png?ixlib=rb-4.1.0&q=15&auto=format&w=600&h=333&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/591482/original/file-20240501-24-esxcic.png?ixlib=rb-4.1.0&q=45&auto=format&w=754&h=418&fit=crop&dpr=1 754w, https://images.theconversation.com/files/591482/original/file-20240501-24-esxcic.png?ixlib=rb-4.1.0&q=30&auto=format&w=754&h=418&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/591482/original/file-20240501-24-esxcic.png?ixlib=rb-4.1.0&q=15&auto=format&w=754&h=418&fit=crop&dpr=3 2262w" alt="The figure shows data for a speed-based task where higher scores represent better performance." /><figcaption>The figure shows data for a speed-based task where higher scores represent better performance. <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></figcaption></figure> I believe the older adults of today are benefiting from many of the factors previously most applicable to young adults. For example, the number of children who went to school <a href="https://education-uk.org/history/chapter12.html">increased significantly</a> in the 1960s – with the system being more similar to what it is today than what it was at the start of the 20th century. This is being reflected in that cohort’s increased scores today, now they are older adults. At the same time, young adults have hit a ceiling and are no longer improving as much with each cohort. It is not entirely clear why the young generations have stopped improving so much. Some research has <a href="https://doi.org/10.1016/j.intell.2016.10.002">explored maternal age, mental health and even evolutionary trends</a>. I favour the opinion that there is just a natural ceiling – a limit to how much factors such as education, nutrition and health can improve cognitive performance. These data have important implications for research into dementia. For example, it is possible that a modern older adult in the early stages of dementia might pass a dementia test that was designed 20 or 30 years ago for the general population at that time. Therefore, as older adults are performing better in general than previous generations, it may be necessary to revise definitions of dementia that depend on an individuals’ expected level of ability. Ultimately, we need to rethink what it means to become older. And there’s finally some good news. Ultimately, we can expect to be more cognitively able than our grandparents were when we reach their age.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/229132/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/stephen-badham-1531316">Stephen Badham</a>, Professor of Psychology, <a href="https://theconversation.com/institutions/nottingham-trent-university-1338">Nottingham Trent University</a> Image credits: Getty Images This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/are-young-people-smarter-than-older-adults-my-research-shows-cognitive-differences-between-generations-are-diminishing-229132">original article</a>. </div>

Mind

Run out of butter or eggs? Here’s the science behind substitute ingredients

<a href="https://theconversation.com/profiles/paulomi-polly-burey-404695">Paulomi (Polly) Burey</a>, <a href="https://theconversation.com/institutions/university-of-southern-queensland-1069">University of Southern Queensland</a> It’s an all too common situation – you’re busy cooking or baking to a recipe when you open the cupboard and suddenly realise you are missing an ingredient. Unless you can immediately run to the shops, this can leave you scrambling for a substitute that can perform a similar function. Thankfully, such substitutes can be more successful than you’d expect. There are a few reasons why certain ingredient substitutions work so well. This is usually to do with the chemistry and the physical features having enough similarity to the original ingredient to still do the job appropriately. Let’s delve into some common ingredient substitutions and why they work – or need to be tweaked. <iframe id="IitfH" class="tc-infographic-datawrapper" style="border: none;" src="https://datawrapper.dwcdn.net/IitfH/1/" width="100%" height="400px" frameborder="0"></iframe> <h2>Oils versus butter</h2> Both butter and oils belong to a chemical class called <a href="https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Map%3A_Fundamentals_of_General_Organic_and_Biological_Chemistry_(McMurry_et_al.)/23%3A_Lipids/23.01%3A_Structure_and_Classification_of_Lipids">lipids</a>. It encompasses solid, semi-solid and liquid fats. In a baked product the “job” of these ingredients is to provide flavour and influence the structure and texture of the finished item. In cake batters, lipids contribute to creating an emulsion structure – this means combining two liquids that wouldn’t usually mix. In the baking process, this helps to create a light, fluffy crumb. One of the primary differences between butter and oil is that butter is only about 80% lipid (the rest being water), while <a href="https://www.nutritionadvance.com/types-of-cooking-fats-and-oils/">oil is almost 100% lipid</a>. Oil creates a softer crumb but is still a great fat to bake with. You can use a wide range of oils from different sources, such as olive oil, rice bran, avocado, peanut, coconut, macadamia and many more. Each of these may impart different flavours. Other “butters”, such as peanut and cashew butter, aren’t strictly butters but pastes. They impart different characteristics and can’t easily replace dairy butter, unless you also add extra oil. <h2>Aquafaba or flaxseed versus eggs</h2> Aquafaba is the liquid you drain from a can of legumes – such as chickpeas or lentils. It contains proteins, kind of how egg white also contains proteins. The proteins in egg white include albumins, and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5912395/">aquafaba also contains albumins</a>. This is why it is possible to make meringue from egg whites, or from aquafaba if you’re after a vegan version. The proteins act as a foam stabiliser – they hold the light, airy texture in the product. The concentration of protein in egg white is a bit higher, so it doesn’t take long to create a stable foam. Aquafaba requires more whipping to create a meringue-like foam, but it will bake in a similar way. Another albumin-containing alternative for eggs is <a href="https://foodstruct.com/compare/seeds-flaxseed-vs-egg">flaxseed</a>. These seeds form a thick gel texture when mixed with a little water. The texture is similar to raw egg and can provide structure and emulsification in baked recipes that call for a small amount of egg white. <h2>Lemon plus dairy versus buttermilk</h2> Buttermilk is the liquid left over after churning butter – it can be made from sweet cream, cultured/sour cream or whey-based cream. Buttermilk mostly <a href="https://www.journalofdairyscience.org/article/S0022-0302(06)72115-4/fulltext">contains proteins and fats</a>. Cultured buttermilk has a somewhat tangy flavour. Slightly soured milk can be a good substitute as it contains similar components and isn’t too different from “real” buttermilk, chemically speaking. One way to achieve slightly soured milk is by adding some lemon juice or cream of tartar to milk. Buttermilk is used in pancakes and baked goods to give extra height or volume. This is because the acidic (sour) components of buttermilk interact with baking soda, producing a light and airy texture. Buttermilk can also influence flavour, imparting a slightly tangy taste to pancakes and baked goods. It can also be used in sauces and dressings if you’re looking for a lightly acidic touch. <h2>Honey versus sugar</h2> Honey is a <a href="https://resources.perkinelmer.com/lab-solutions/resources/docs/APP_Analysis-of-Sugars-in-Honey-012101_01.pdf">complex sugar-based syrup</a> that includes floral or botanical flavours and aromas. Honey can be used in cooking and baking, adding both flavour and texture (viscosity, softness) to a wide range of products. If you add honey instead of regular sugar in baked goods, keep in mind that honey imparts a softer, moister texture. This is because it contains more moisture and is a humectant (that is, it likes to hold on to water). It is also less crystalline than sugar, unless you leave it to crystallise. The intensity of sweetness can also be different – some people find honey is sweeter than its granular counterpart, so you will want to adjust your recipes accordingly. <h2>Gluten-free versus regular flour</h2> Sometimes you need to make substitutions to avoid allergens, such as gluten – the protein found in cereal grains such as wheat, rye, barley and others. Unfortunately, gluten is also the component that gives a nice, stretchy, squishy quality to bread. To build this characteristic in a gluten-free product, it’s necessary to have a mixture of ingredients that work together to mimic this texture. Common ingredients used are corn or rice flour, xanthan gum, which acts as a binder and moisture holder, and tapioca starch, which is a good water absorbent and can aid with binding the dough. <img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/202036/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/paulomi-polly-burey-404695">Paulomi (Polly) Burey</a>, Associate Professor (Food Science), <a href="https://theconversation.com/institutions/university-of-southern-queensland-1069">University of Southern Queensland</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/run-out-of-butter-or-eggs-heres-the-science-behind-substitute-ingredients-202036">original article</a>.

Food & Wine

Science finally proves "Money doesn't buy happiness"

A new study has proven that the old adage "money can't buy you happiness" is true. Historically, economic wealth and higher income households are often seen to have an increased level of wellbeing and happiness, with the extra money making way for less stress and more general comfortability. However, researchers from Canada and Spain have concluded this may not be true, with such surveys often including responses from people in industrialised areas only. People in small-scale societies where money does not play a central role in every day life are often excluded from these studies, as the livelihood of residents in these small communities usually depend more on nature. Now, 2,966 people from Indigenous and local communities in 19 locations across the globe have been included in a study, with researchers now finding that societies of Indigenous people and those in small, local communities report living very satisfying lives despite not having a lot of money. The researchers wrote, "The striking aspect of our findings... is that reported life satisfaction in very low-income communities can meet and even exceed that reported at the highest average levels of material wealth provided by industrial ways of life." Researchers concluded the findings are strong evidence that economic growth is not needed to be happy, with only 64 percent of households included in the survey reported having any cash income. Eric Galbraith, lead author of the study, said, "Surprisingly, many populations with very low monetary incomes report very high average levels of life satisfaction, with scores similar to those in wealthy countries." Researchers added that high life satisfaction is shown in these communities "despite many of these societies having suffered histories of marginalisation and oppression." Galbraith added, "I would hope that, by learning more about what makes life satisfying in these diverse communities, it might help many others to lead more satisfying lives while addressing the sustainability crisis." Image credits: Shutterstock

Money & Banking

How to make the perfect pavlova, according to chemistry experts

<a href="https://theconversation.com/profiles/nathan-kilah-599082">Nathan Kilah</a>, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a> and <a href="https://theconversation.com/profiles/chloe-taylor-1400788">Chloe Taylor</a>, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a> The pavlova is a summer icon; just a few simple ingredients can be transformed into a beautifully flavoured and textured dessert. But despite its simplicity, there’s a surprising amount of chemistry involved in making a pavlova. Knowing what’s happening in each step is a sure-fire way to make yours a success. So exactly what does it take to make the perfect pavlova? Let us break it down for you. <h2>Egg whites</h2> <a href="https://theconversation.com/eight-cracking-facts-about-eggs-150797">Egg white</a> is basically a mixture of proteins in water. Two of these proteins, ovalbumin and ovomucin, are the key to forming a perfect foamy meringue mixture. Whipping the egg whites agitates the proteins and disrupts their structure, causing them to unfold so the protein’s interior surface is exposed, in a process <a href="https://theconversation.com/sunny-side-up-can-you-really-fry-an-egg-on-the-footpath-on-a-hot-day-172616">known as denaturing</a>. These surfaces then join with one another to trap air bubbles and turn into a stable foam. Egg yolk must be completely removed for this process to work. Yolk is mostly made of fat molecules, which would destabilise the protein network and pop the air bubbles. It only takes a trace amount of fat, or even just a greasy bowl, to disrupt foam formation. You should always whip your egg whites in a clean glass or metal bowl. Plastic bowls are more likely to hold leftover grease. <h2>Sugar</h2> A traditional pavlova uses sugar – a lot of it – to provide texture and flavour. The ratio of sugar to egg white will differ between recipes. The first thing to remember is that adding more sugar will give you a drier and crispier texture, whereas less sugar will lead to a softer and chewier pavlova that won’t keep as long. The second thing is the size of the sugar crystals. The larger they are, the longer they’ll need to be whipped to dissolve, and the greater the chance you will overwork the proteins in your meringue. Powdered icing sugar (not icing mixture) is preferable to caster or granulated sugar. If you do happen to overbeat your meringue (which may end up looking clumpy and watery) you can try to save it by adding another egg white. <h2>Acid</h2> Many pavlova recipes call for adding cream of tartar or vinegar. Cream of tartar is also known as potassium hydrogen tartrate, which you may have seen in the form of crystals at the <a href="https://theconversation.com/louis-pasteurs-scientific-discoveries-in-the-19th-century-revolutionized-medicine-and-continue-to-save-the-lives-of-millions-today-191395">bottom of a wine glass</a>. These acids act as a stabilising agent for the meringue by aiding in the unfolding of the egg white proteins. More isn’t always better, though. Using too much stabiliser can affect the taste and texture, so use it sparingly. <h2>Heat</h2> Cooking a pavlova requires a very slow oven for specific chemical reasons. Namely, egg white proteins gel at temperatures above 60°C, setting the meringue. At higher temperatures a chemical reaction known as the <a href="https://theconversation.com/kitchen-science-from-sizzling-brisket-to-fresh-baked-bread-the-chemical-reaction-that-makes-our-favourite-foods-taste-so-good-58577">Maillard reaction</a> takes place in which proteins and sugars react to form new flavourful compounds. We can thank the Maillard reaction for many delicious foods including <a href="https://theconversation.com/brewing-a-great-cup-of-coffee-depends-on-chemistry-and-physics-84473">roasted coffee</a>, toast and <a href="https://theconversation.com/what-makes-smoky-charred-barbecue-taste-so-good-the-chemistry-of-cooking-over-an-open-flame-184206">seared steak</a>. However, excessive Maillard reactions are undesirable for a pavlova. An oven that’s too hot will turn your meringue brown and give it a “caramelised” flavour. Recipes calling for pavlova to be left in the oven overnight may actually overcook it. At the same time, you don’t want to accidentally undercook your pavlova – especially since uncooked eggs are often responsible for <a href="https://theconversation.com/how-to-avoid-food-borne-illness-a-nutritionist-explains-153185">food poisoning</a>. To kill dangerous bacteria, including salmonella, the pavlova’s spongy centre must reach <a href="https://foodsafety.asn.au/eggs/">temperatures above 72°C</a>. An alternative is to use pasteurised egg whites, which are briefly heated to a very high temperature to kill any pathogens. But this processing may also affect the egg white’s whippability. <h2>Substitute ingredients</h2> People love pavlova, and nobody should have to miss out. Luckily they don’t have to. If you want to <a href="https://theconversation.com/a-taste-for-sweet-an-anthropologist-explains-the-evolutionary-origins-of-why-youre-programmed-to-love-sugar-173197">limit your sugar intake</a>, you can make your meringue using sweeteners such as <a href="https://theconversation.com/whats-the-difference-between-sugar-other-natural-sweeteners-and-artificial-sweeteners-a-food-chemist-explains-sweet-science-172571">powdered erythritol or monk fruit</a>. But, if you do, you may want to add some extra stabiliser such as cornflour, arrowroot starch, or a pinch of xanthan gum to maintain the classic texture. Also, if you want a vegan pavlova, you can turn to the chickpea instead of the chicken! <a href="https://review.jove.com/t/56305/composition-properties-aquafaba-water-recovered-from-commercially">Aquafaba</a> – the water collected from tinned or soaked beans – contains proteins and carbohydrates that give it emulsifying, foaming and even thickening properties. Egg-free pavlova recipes typically replace one egg white with about two tablespoons of aquafaba. And for those of you who don’t do gluten, pavlova can easily be made <a href="https://theconversation.com/gluten-free-diet-is-expensive-socially-challenging-for-those-with-celiac-disease-and-wheat-allergy-155861">gluten-free</a> by using certain stabilising agents. All that’s left is to get creative with your toppings and decide what to do with those leftover yolks!<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/196485/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/nathan-kilah-599082">Nathan Kilah</a>, Senior Lecturer in Chemistry, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a> and <a href="https://theconversation.com/profiles/chloe-taylor-1400788">Chloe Taylor</a>, Research Fellow - PhD candidate, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a> Image credits: Getty Images This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/how-to-make-the-perfect-pavlova-according-to-chemistry-experts-196485">original article</a>.

Food & Wine

Worrying news – ozone layer not recovering after all

Alarming news from New Zealand scientists suggests the ozone layer might not be recovering after all, with the problem exacerbated by bushfires, volcanic eruptions and greenhouse gas emissions. <div class="copy"> The research <a href="https://doi.org/10.1038/s41467-023-42637-0" target="_blank" rel="noopener">published</a> in Nature Communications suggests the Antarctic ozone layer has reduced by 26% since 2004, contrary to previous reports of recovery by actions taken under an agreement called the Montreal Protocol. The authors say wildfire and volcanic aerosols together with greenhouse gas emissions probably explain recent setbacks with record large, long-lived ozone holes re-emerging over Antarctica during Spring since 2020. Climate change is influencing the <a href="http://www.bom.gov.au/weather-services/fire-weather-centre/bushfire-weather/index.shtml" target="_blank" rel="noopener">severity and frequency</a> of bushfires. The ozone hole was previously thought to be under repair thanks to a global agreement signed in Montreal, Canada to limit ozone depleting substances. But the paper finds insignificant long-term change in the total ozone column since the early 2000s, “even where significant recovery has previously been reported”. The analysis of daily and monthly ozone changes between 2001 – 2022, show delays in the formation of the ozone hole. While early springtime shows signs of recovery in the ozone layer, this is followed by declines during late September. Researcher and author Hannah Kessenich from the University of Otago says: “by looking at detailed, daily ozone observations from the last 19 years, we find evidence of much less ozone in the centre of the Antarctic ozone hole compared to 19 years ago. This means that the hole has not only remained large in area, but it has also become deeper (i.e. has less ozone) throughout most of Antarctic spring.” But Atmospheric scientist, Dr Martin Jucker from the University of NSW is not convinced by the results of the study. He says: “Their results rely heavily on the large ozone holes we have seen in 2020-2022. However, existing literature has already found reasons for these large ozone holes: Smoke from the 2019 bushfires and a volcanic eruption (La Soufriere), as well as a general relationship between the polar stratosphere and El Niño Southern Oscillation […] The years 2020-22 have seen a rare triple La Niña, but this relationship is never mentioned in the study.” <a href="https://cosmosmagazine.com/earth/earth-sciences/ozone-hole-among-largest-on-record/">This Spring</a>, the European Space Agency reported yet another large ozone hole had formed, among the biggest on record. The layer of ozone high in the atmosphere protects the Earth from ultraviolet (UV) radiation from the Sun. Ozone depletion exposes people, particularly in the Southern Hemisphere, to a higher risk of skin cancer. Image credits: Getty Images <div> <img id="cosmos-post-tracker" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=288486&title=Worrying+news+%26%238211%3B+ozone+layer+not+recovering+after+all" width="1" height="1" loading="lazy" aria-label="Syndication Tracker" data-spai-target="src" data-spai-orig="" data-spai-exclude="nocdn" /><a href="https://cosmosmagazine.com/earth/climate/ozone-layer-not-recovering/">This article</a> was originally published on <a href="https://cosmosmagazine.com">Cosmos Magazine</a> and was written by <a href="https://cosmosmagazine.com/contributor/petra-stock/">Petra Stock</a>. </div> </div>

Travel Trouble

Sweet secrets – the science of keeping good news hush hush

Most people keep secrets, and staying hush about good news – like pregnancy, presents, proposals and promotions – tends to be freely chosen, enjoyable and energising according to new research. <div class="copy"> Conventional wisdom holds that secrecy is a burden, and good news is <a href="https://cosmosmagazine.com/health/body-and-mind/seeing-emotions/">meant to be shared</a>. But Australian and United States researchers <a href="https://dx.doi.org/10.1037/pspa0000352" target="_blank" rel="noopener">publishing</a> in the Journal of Personality and Social Psychology investigated the effects of keeping positive news to one’s self, finding the motivations and effects are quite different to other types of secrets. Associate Professor Katharine Greenaway researches <a href="https://cosmosmagazine.com/people/society/are-sciences-equal/">social psychology</a> at the University of Melbourne and is an author of the paper. She tells Cosmos: “secrecy is extremely common – on average, 97% of people are keeping a secret right now.” “It’s obviously fascinating to know, people’s secrets, and why they keep them,” she says. Greenaway adds studying secrecy is “really interesting theoretically because we’re social creatures. From our evolutionary past, we’ve always had to be social, we’ve had to communicate in order to co-operate. So, from that perspective it’s really interesting, why would we ever want to keep information from other people? […] It’s particularly interesting why we would keep positive information from others.” Across 5 different experiments involving 2,500 participants the researchers tested different elements of positive secrecy: the effect of secret and non-secret good news; deliberately keeping news secret for personal reasons compared to external reasons ; and the effects of positive secrets compared to other kinds of secrets. “Positive secrets, we’ve found, tend to be the types of secrets people choose freely, and they actually quite enjoy keeping,” Greenaway says. In one study, involving 194 people, participants were provided with a list of 38 common categories of good news, such as: pregnancy; won something; new possession; financial windfall; family news; and self-development. They were asked to indicate which items were relevant, and any they were keeping secret. On average, participants held 14 to 15 pieces of good news, keeping 5 to 6 positive items to themselves. A second study tested motivation. A new group of 600 participants in committed relationships were asked to imagine a plausible piece of good news (from the list of common good news). They were randomly assigned to imagine either: deciding to keep the news secret until they chose share it with their partner, or the information remaining unknown due to external factors like being in meetings all day. For a further group, no reason was specified for not sharing the news. Participants were then asked about how “tired, depleted, weak, passive, active, invigorated, strong, energized, awake and alert, and alive they felt” on a scale from not at all ‘1’ to very much ‘7’. When people elected to keep a piece of good news private, they felt energised. But when external factors got in the way of sharing information, they felt fatigued. <iframe title="People are Seriously becoming Friends with their Robotic Vacuums" src="https://omny.fm/shows/huh-science-explained/people-are-seriously-becoming-friends-with-their-r/embed?in_playlist=podcast&style=Cover" width="100%" height="180" frameborder="0"></iframe> Three further experiments tested the effect of positive or negative secrets. Finding positive secrets were more likely to be kept for personal reasons, freely chosen, generating greater feelings of energy. “When people keep a positive secret as opposed to a different type of secret, they tend to have relatively more intrinsic motivation for doing so. Intrinsic motivation is associated with feeling like something is really important, personally valuable to you. And also enjoyable,” says Greenaway. “If you’ve kept a negative secret, often you’re worried about what would happen if that secret got out […] you feel as though that’s something that’s being imposed on you, as opposed to something that you’re freely choosing to keep secret from others.” Prior research has mostly focused on negative secrets, suggesting secrecy can be harmful. In contrast, this new research suggests holding on to positive news is more likely to be freely chosen, for personal reasons, and can be more energising than sharing the information. Image credits: Getty Images <div> <noscript data-spai="1">&lt;img decoding="async" fetchpriority="high" class="aligncenter size-full wp-image-198773" src="https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2023/11/Cosmos-Catch-Up-embed_728x150-1.jpg" data-spai-egr="1" alt="Sign up to our weekly newsletter" width="600" height="154" title="sweet secrets - the science of keeping good news hush hush 2"&gt;</noscript> </div>  <img id="cosmos-post-tracker" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=288402&title=Sweet+secrets+%26%238211%3B+the+science+of+keeping+good+news+hush+hush" width="1" height="1" loading="lazy" aria-label="Syndication Tracker" data-spai-target="src" data-spai-orig="" data-spai-exclude="nocdn" /><a href="https://cosmosmagazine.com/people/social-sciences/sweet-secrets-science/">This article</a> was originally published on <a href="https://cosmosmagazine.com">Cosmos Magazine</a> and was written by <a href="https://cosmosmagazine.com/contributor/petra-stock/">Petra Stock</a>. </div>

Mind

Can coffee help you avoid weight gain? Here’s what the science says

Body

Can a daily multivitamin improve your memory?

<a href="https://theconversation.com/profiles/jacques-raubenheimer-1144463">Jacques Raubenheimer</a>, <a href="https://theconversation.com/institutions/university-of-sydney-841">University of Sydney</a> <a href="https://theconversation.com/au/topics/research-check-25155">Research Checks</a> interrogate newly published studies and how they’re reported in the media. The analysis is undertaken by one or more academics not involved with the study, and reviewed by another, to make sure it’s accurate. <hr /> Don’t we all want to do what we can to reduce the impact of age-related decline on our memory? A new study suggests a daily multivitamin and mineral supplement is a simple and inexpensive way to help older adults slow the decline in some aspects of memory function. The <a href="https://ajcn.nutrition.org/article/S0002-9165(23)48904-6/fulltext">new study</a>, which comes from a <a href="https://www.clinicaltrials.gov/ct2/show/NCT02422745?term=NCT02422745&draw=2&rank=1">long-running clinical trial</a>, shows there may be a small benefit of taking a daily multivitamin and mineral supplement for one type of cognitive task (immediate word recall) among well-functioning elderly white people. At least in the short term. But that doesn’t mean we should all rush out and buy multivitamins. The results of the study don’t apply to the whole population, or to all types of memory function. Nor does the study show long-term benefits. <h2>How was the study conducted?</h2> The overarching COSMOS study is a well-designed double-blind randomised control trial. This means participants were randomly allocated to receive the intervention (a daily multivitamin and mineral supplement) or a placebo (dummy tablet), but neither the participants nor the researchers knew which one they were taking. This type of study is considered the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5654877/">gold standard</a> and allows researchers to compare various outcomes. Participants (3,562) were older than 64 for women, and 59 for men, with no history of heart attack, invasive cancer, stroke or serious illness. They couldn’t use multivitamins or minerals (or <a href="https://www.pnas.org/doi/10.1073/pnas.2216932120">cocoa extract</a> which they also tested) during the trial. Participants completed a <a href="https://www.clinicaltrials.gov/ct2/show/NCT04582617?term=NCT04582617&draw=2&rank=1">battery of online cognitive tests</a> at the start of the study (known as baseline), then yearly for three years, of which only three were reported in this paper: <ul> <li> ModRey, measuring immediate recall. Participants were shown “a list of 20 words, one at a time, for three seconds each,” and then had to type the list from memory </li> <li> ModBent, measuring object recognition. Participants were given 20 prompts with a shape and then had to select the correct match from a pair of similar prompts. After this, they were prompted with 40 shapes in turn, and had to indicate whether each was included in the original 20 or not </li> <li> Flanker, measuring “executive control”. Participants had to select a coloured block that corresponded to an arrow in a matrix of arrows, which could have the same (or different) colour to the surrounding arrows, and the same (or different) direction as the prompt block. </li> </ul> <h2>What did the researchers find?</h2> Of all the tests the researchers performed, only immediate recall (ModRey) at one year showed a significant effect, meaning the result is unlikely to just be a result of chance. At two and three years, the effect was no longer significant (meaning it could be down to chance). However they added an “overall estimate” by averaging the results from all three years to arrive at another significant effect. All the effect sizes reported are very small. The largest effect is for the participants’ immediate recall at one year, which was 0.07 – a value that is <a href="https://academic.oup.com/jpepsy/article/34/9/917/939415">generally considered very small without justification</a>. Also of note is that both the multivitamin and placebo groups had higher immediate word recall scores at one year (compared to baseline), although the multivitamin group’s increase was significantly larger. <a href="https://www.pnas.org/doi/epdf/10.1073/pnas.2216932120">In the researchers’ prior study</a>, the increase in word recall scores was described as a “typical learning (practice) effect”. This means they attributed the higher scores at one year to familiarisation with the test. For some reason, this “learning effect” was not discussed in the current paper, where the treatment group showed a significantly larger increase compared to those who were given the placebo. <h2>What are the limitations of the study?</h2> The team used a suitable statistical analysis. However, it did not adjust for demographic characteristics such as age, gender, race, and level of education. The authors detail their study’s major limitation well: it is not very generalisable, as it used “mostly white participants” who had to be very computer literate, and, one could argue, would be quite well-functioning cognitively. <figure class="align-center "><figcaption></figcaption>Another unmentioned limitation is the advanced age of their sample, meaning long-term results for younger people can’t be assessed.</figure> Additionally, the baseline diet score for their sample was abysmal. The researchers say participants’ diet scores “were consistent with <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1899558">averages from the US population</a>” but the cited study noted “the overall dietary quality… [was] poor.” And they didn’t measure changes in diet over the three years, which could impact the results. <h2>How should we interpret the results?</h2> The poor dietary quality of the sample raises the question: can a better diet be the simple fix, rather than multivitamin and mineral supplements? Even for the effect they observed, which micronutrient from the supplement was the contributing factor? The researchers speculate about vitamins B12 and D. But you can find research on cognitive function for any arbitrarily chosen <a href="https://www.centrum.com/content/dam/cf-consumer-healthcare/bp-wellness-centrum/en_US/pdf/lbl-00000775-web-ready-centrum-silver-adults-tablets-(versio.pdf">ingredient</a>, including <a href="https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=selenium+cognitive+function">selenium</a>, which can be <a href="https://www.sciencedirect.com/science/article/pii/S0048969720378608">toxic at high levels</a>. <h2>So should I take a multivitamin?</h2> <a href="https://newsinhealth.nih.gov/2013/08/should-you-take-dietary-supplements">Health authorities advise</a> daily multivitamin use isn’t necessary, as you can get all the nutrients you need by eating a wide variety of healthy foods. However, supplementation may be appropriate to meet any specific nutrient gaps an individual has. Using a good quality multivitamin at the recommended dose shouldn’t do any harm, but at best, this study shows well-functioning elderly white people might show some additional benefit in one type of cognitive task from using a multivitamin supplement. The case for most of the rest of the population, and the long-term benefit for younger people, can’t be made. <hr /> <h2>Blind peer review</h2> Clare Collins writes: I agree with the reviewer’s assessment, which is a comprehensive critique of the study. The key result was a small effect size from taking a daily multivitamin and mineral (or “multinutrient”) supplement on memory recall at one year (but not later time points) and is equivalent to a training effect where you get better at taking a test the more times you do it. It’s also worth noting the study authors received support and funding from commercial companies to undertake the study. While the study authors state they don’t believe background diet quality impacted the results, they didn’t comprehensively assess this. They used a brief <a href="https://pubmed.ncbi.nlm.nih.gov/22513989/">diet quality assessment score</a> only at baseline. Participants may have changed their eating habits during the study, which could then impact the results. Given all participants reported low diet quality scores, an important question is whether giving participants the knowledge, skills and resources to eat more healthily would have a bigger impact on cognition than taking supplements. <img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/208114/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> Image credit: Shutterstock <a href="https://theconversation.com/profiles/jacques-raubenheimer-1144463">Jacques Raubenheimer</a>, Senior Research Fellow, Biostatistics, <a href="https://theconversation.com/institutions/university-of-sydney-841">University of Sydney</a> This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/can-a-daily-multivitamin-improve-your-memory-208114">original article</a>.

Body

The science of dreams and nightmares – what is going on in our brains while we’re sleeping?

<a href="https://theconversation.com/profiles/drew-dawson-13517">Drew Dawson</a>, <a href="https://theconversation.com/institutions/cquniversity-australia-2140">CQUniversity Australia</a> and <a href="https://theconversation.com/profiles/madeline-sprajcer-1315489">Madeline Sprajcer</a>, <a href="https://theconversation.com/institutions/cquniversity-australia-2140">CQUniversity Australia</a> Last night you probably slept for <a href="https://www.sciencedirect.com/science/article/pii/S2352721816301292">seven to eight hours</a>. About one or two of these was likely in deep sleep, especially if you’re young or physically active. That’s because <a href="http://apsychoserver.psych.arizona.edu/jjbareprints/psyc501a/readings/Carskadon%20Dement%202011.pdf">sleep changes with age</a> and <a href="https://www.hindawi.com/journals/apm/2017/1364387/">exercise</a> affects brain activity. About three or four hours will have been spent in light sleep. For the remaining time, you were likely in rapid eye movement (REM) sleep. While this is not the only time your brain is potentially dreaming – we also dream during other sleep stages – it is the time your brain activity is most likely to be recalled and reported when you’re awake. That’s usually because either really weird thoughts or feelings wake you up or because the last hour of sleep is nearly all <a href="https://www.researchgate.net/profile/Elizaveta-Solomonova/publication/320356182_Dream_Recall_and_Content_in_Different_Stages_of_Sleep_and_Time-of-Night_Effect/links/5a707bdb0f7e9ba2e1cade56/Dream-Recall-and-Content-in-Different-Stages-of-Sleep-and-Time-of-Night-Effect.pdf">REM sleep</a>. When dreams or your alarm wake you, you’re likely coming out of dream sleep and your dream often lingers into the first few minutes of being awake. In this case you remember it. If they’re strange or interesting dreams, you might tell someone else about them, which may further <a href="https://link.springer.com/article/10.1007/s00426-022-01722-7">encode</a> the dream memory. Dreams and nightmares are mysterious and we’re still learning about them. They keep our brains ticking over. They wash the thoughts from the day’s events at a molecular level. They might even help us imagine what’s possible during our waking hours. <h2>What do scientists know about REM sleep and dreaming?</h2> It’s really hard to study dreaming because people are asleep and we can’t observe what’s going on. Brain imaging has indicated certain <a href="https://www.sciencedirect.com/science/article/pii/S1087079216300673#sec3">patterns of brain activity</a> are associated with dreaming (and with certain sleep stages where dreams are more likely to occur). But such studies ultimately rely on self-reports of the dream experience. Anything we spend so much time doing probably serves multiple ends. At the basic physiological level (indicated by <a href="https://www.sciencedirect.com/science/article/pii/S1053810021001409">brain activity, sleep behaviour and studies of conciousness</a>), all mammals dream – even the platypus and echidna probably experience something similar to dreaming (provided they are at the <a href="https://www.wired.com/2014/07/the-creature-feature-10-fun-facts-about-the-echidna/#:%7E:text=It%20was%20long%20thought%20that,re%20at%20the%20right%20temperature.">right temperature</a>). Their brain activity and sleep stages align to some degree with human <a href="https://www.sciencedirect.com/science/article/pii/S1053810021001409#b0630">REM sleep</a>. Less evolved species do not. Some <a href="https://www.sciencedirect.com/science/article/pii/S2468867319301993#sec0030">jellyfish</a> – who do not have a brain – do experience what could physiologically be characterised as sleep (shown by their posture, quietness, lack of responsiveness and rapid “waking” when prompted). But they do not experience the same physiological and behavioural elements that resemble REM dream sleep. In humans, REM sleep is thought to occur cyclically every 90 to 120 minutes across the night. It prevents us from sleeping too deeply and being <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4972941/">vulnerable to attack</a>. Some scientists think we dream in order to stop our brains and bodies from getting too cold. Our core body temperature is typically <a href="https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(22)00210-1/fulltext">higher while dreaming</a>. It is typically easier to <a href="https://www.tandfonline.com/doi/pdf/10.2147/NSS.S188911">wake from dreaming</a> if we need to respond to external cues or dangers. The brain activity in REM sleep kicks our brain into gear for a bit. It’s like a periscope into a more conscious state, observing what’s going on at the surface, then going back down if all is well. Some evidence suggests “fever dreams” are far less common than we might expect. We actually experience <a href="https://www.frontiersin.org/articles/10.3389/fpsyg.2020.00053/full">far less REM sleep</a> when we have a fever – though the dreams we do have tend to be <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3830719/">darker in tone and more unusual</a>. Spending less time in REM sleep when we’re feverish might happen because we are far less capable of regulating our body temperature in this stage of sleep. To protect us, our brain tries to regulate our temperature by “skipping” this sleep stage. We tend to have fewer dreams when the weather is hot <a href="https://www.tandfonline.com/doi/abs/10.1080/23744731.2020.1756664">for the same reason</a>. <h2>A deep-cleaning system for the brain</h2> REM sleep is important for ensuring our brain is working as it should, as indicated by studies using <a href="https://www.cell.com/current-biology/pdf/S0960-9822(17)31329-5.pdf">electoencephalography</a>, which measures brain activity. In the same way deep sleep helps the body restore its physical capacity, dream sleep “<a href="https://www.cell.com/current-biology/pdf/S0960-9822(17)31329-5.pdf">back-flushes</a>” our neural circuits. At the molecular level, the chemicals that underpin our thinking are bent out of shape by the day’s cognitive activity. Deep sleep is when those chemicals are returned to their unused shape. The brain is “<a href="https://www.science.org/doi/abs/10.1126/science.1241224">washed</a>” with cerebrospinal fluid, controlled by the <a href="https://theconversation.com/on-your-back-side-face-down-mice-show-how-we-sleep-may-trigger-or-protect-our-brain-from-diseases-like-als-181954">glymphatic system</a>. At the next level, dream sleep “tidies up” our recent memories and feelings. During <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC534695/">REM sleep</a>, our brains consolidate procedural memories (of how to do tasks) and emotions. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC534695/">Non-REM sleep</a>, where we typically expect fewer dreams, is important for the consolidation of episodic memories (events from your life). As our night’s sleep progresses, we produce more cortisol - the <a href="https://psycnet.apa.org/record/2005-01907-021">stress hormone</a>. It is thought the amount of cortisol present can impact the type of memories we are consolidating and potentially the types of dreams we have. This means the dreams we have later in the night may be <a href="https://learnmem.cshlp.org/content/11/6/671.full.pdf">more fragmented or bizarre</a>. Both kinds of sleep help <a href="https://www.researchgate.net/profile/Jb-Eichenlaub/publication/313545620_Daily_Life_Experiences_in_Dreams_and_Sleep-Dependent_Memory_Consolidation/links/5c532b0ba6fdccd6b5d76270/Daily-Life-Experiences-in-Dreams-and-Sleep-Dependent-Memory-Consolidation.pdf?ref=nepopularna.org">consolidate</a> the useful brain activity of the day. The brain also discards less important information. <h2>Random thoughts, rearranged feelings</h2> This filing and discarding of the day’s activities is going on while we are sleeping. That’s why we often dream about things that happen <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0264574">during the day</a>. Sometimes when we’re rearranging the thoughts and feelings to go in the “<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3921176/">bin</a>” during sleep, our level of consciousness allows us to experience awareness. Random thoughts and feelings end up all jumbled together in weird and wonderful ways. Our awareness of this process may explain the bizarre nature of some of our dreams. Our daytime experiences can also fuel nightmares or anxiety-filled dreams after a <a href="https://www.sleepfoundation.org/dreams/how-trauma-can-affect-dreams">traumatic event</a>. Some dreams appear to <a href="https://rai.onlinelibrary.wiley.com/doi/pdfdirect/10.1111/j.1467-9655.2010.01668.x">foretell the future or carry potent symbolism</a>. In many societies dreams are believed to be a window into an <a href="https://digitalcommons.ciis.edu/cgi/viewcontent.cgi?article=1050&context=ijts-transpersonalstudies">alternate reality</a> where we can envisage what is possible. <h2>What does it all mean?</h2> Our scientific understanding of the thermoregulatory, molecular and basic neural aspects of dreaming sleep is <a href="https://www.nature.com/articles/nrn2716">good</a>. But the psychological and spiritual aspects of dreaming remain largely hidden. Perhaps our brains are wired to try and make sense of things. Human societies have always interpreted the random – birds wheeling, tea leaves and the planets – and looked for <a href="https://brill.com/display/book/edcoll/9789047407966/B9789047407966-s003.xml">meaning</a>. Nearly every human society has regarded dreams as more than just random neural firing. And the history of science tells us some things once thought to be magic can later be understood and harnessed – for better or worse.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/210901/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/drew-dawson-13517">Drew Dawson</a>, Director, Appleton Institute, <a href="https://theconversation.com/institutions/cquniversity-australia-2140">CQUniversity Australia</a> and <a href="https://theconversation.com/profiles/madeline-sprajcer-1315489">Madeline Sprajcer</a>, Lecturer in Psychology, <a href="https://theconversation.com/institutions/cquniversity-australia-2140">CQUniversity Australia</a> Image credits: Shutterstock This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/the-science-of-dreams-and-nightmares-what-is-going-on-in-our-brains-while-were-sleeping-210901">original article</a>.

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Anti-cellulite products are big business – but here’s what the science says

Michael Mosley used science communication to advance health and wellbeing. We can learn a lot from his approach

Are young people smarter than older adults? My research shows cognitive differences between generations are diminishing

Run out of butter or eggs? Here’s the science behind substitute ingredients

Science finally proves "Money doesn't buy happiness"

How to make the perfect pavlova, according to chemistry experts

Worrying news – ozone layer not recovering after all

Sweet secrets – the science of keeping good news hush hush

Can coffee help you avoid weight gain? Here’s what the science says

Can a daily multivitamin improve your memory?

The science of dreams and nightmares – what is going on in our brains while we’re sleeping?