Search

Fasting, eating earlier in the day or eating fewer meals – what works best for weight loss?

<div class="theconversation-article-body"><a href="https://theconversation.com/profiles/hayley-oneill-1458016">Hayley O'Neill</a>, <a href="https://theconversation.com/institutions/bond-university-863">Bond University</a> and <a href="https://theconversation.com/profiles/loai-albarqouni-452476">Loai Albarqouni</a>, <a href="https://theconversation.com/institutions/bond-university-863">Bond University</a> Globally, <a href="https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight">one in eight people</a> are living with obesity. This is an issue because <a href="https://www.aihw.gov.au/reports/risk-factors/risk-factors-to-health/contents/overweight-and-obesity">excess fat</a> <a href="https://pubmed.ncbi.nlm.nih.gov/27423262/">increases the risk</a> of type 2 diabetes, heart disease and certain cancers. <a href="https://pubmed.ncbi.nlm.nih.gov/33393504/">Modifying your diet</a> is important for managing obesity and preventing weight gain. This might include reducing your calorie intake, changing your <a href="https://pubmed.ncbi.nlm.nih.gov/39143663/">eating patterns</a> and prioritising healthy food. But is one formula for weight loss more likely to result in success than another? Our <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC11530941/">new research</a> compared three weight-loss methods, to see if one delivered more weight loss than the others: <ul> <li>altering calorie distribution – eating more calories earlier rather than later in the day</li> <li>eating fewer meals</li> <li>intermittent fasting.</li> </ul> We analysed data from 29 clinical trials involving almost 2,500 people. We found that over 12 weeks or more, the three methods resulted in similar weight loss: 1.4–1.8kg. So if you do want to lose weight, choose a method that works best for you and your lifestyle. <h2>Eating earlier in the day</h2> When our metabolism <a href="https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/metabolic-syndrome">isn’t functioning properly</a>, our body can’t respond to the hormone insulin properly. This can lead to weight gain, fatigue and can increase the risk of a number of chronic diseases such as diabetes. Eating later in the day – with a <a href="https://pubmed.ncbi.nlm.nih.gov/23512957/">heavy dinner</a> and late-night snacking – seems to lead to <a href="https://pubmed.ncbi.nlm.nih.gov/33172509/">worse metabolic function</a>. This means the body becomes less efficient at converting food into energy, managing blood sugar and regulating fat storage. In contrast, consuming calories <a href="https://pubmed.ncbi.nlm.nih.gov/31151228/">earlier</a> in the day appears to <a href="https://pubmed.ncbi.nlm.nih.gov/29754952/">improve</a> metabolic function. However, this might not be the case for everyone. Some people naturally have an evening “chronotype”, meaning they wake up and stay up later. People with this chronotype appear to have <a href="https://pubmed.ncbi.nlm.nih.gov/36803075/">less success losing weight</a>, no matter the method. This is due to a combination of factors including genes, an increased likelihood to have a poorer diet overall and higher levels of hunger hormones. <h2>Eating fewer meals</h2> <a href="https://pubmed.ncbi.nlm.nih.gov/30700403/">Skipping breakfast</a> is common, but does it hinder weight loss? Or is a <a href="https://pubmed.ncbi.nlm.nih.gov/28967343/">larger breakfast and smaller dinner</a> ideal? While <a href="https://pubmed.ncbi.nlm.nih.gov/28137935/">frequent meals</a> may reduce disease risk, recent studies suggest that compared to eating one to two meals a day, eating six times a day might increase <a href="https://pubmed.ncbi.nlm.nih.gov/32437566/">weight loss success</a>. However, this doesn’t reflect the broader research, which tends to show consuming <a href="https://pubmed.ncbi.nlm.nih.gov/33485709/">fewer meals</a> can lead to greater weight loss. <a href="https://pubmed.ncbi.nlm.nih.gov/39485353/">Our research</a> suggests three meals a day is better than six. The easiest way to do this is by cutting out snacks and keeping breakfast, lunch and dinner. Most studies compare three versus six meals, with limited evidence on whether <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC7490164/">two meals is better than three</a>. However, <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC11530941/">front-loading your calories</a> (consuming most of your calories between breakfast and lunch) appears to be better for weight loss and may also help <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC9605877/">reduce hunger</a> across the day. But more studies with a longer duration are needed. <h2>Fasting, or time-restricted eating</h2> Many of us eat over a period of more than <a href="https://pubmed.ncbi.nlm.nih.gov/26411343/">14 hours a day</a>. Eating late at night <a href="https://pubmed.ncbi.nlm.nih.gov/26411343/">can throw off</a> your body’s natural rhythm and alter how your organs function. Over time, this can increase your risk of type 2 diabetes and other chronic diseases, particularly among <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC8617838/">shift workers</a>. <a href="https://pubmed.ncbi.nlm.nih.gov/35194176/">Time-restricted eating</a>, a form of intermittent fasting, means eating all your calories within a <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC7262456/">six- to ten-hour window</a> during the day when you’re most active. It’s not about changing what or how much you eat, but <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC7262456/">when you eat it</a>. <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC7262456/">Animal studies</a> suggest time-restricted eating can lead to weight loss and improved metabolism. But the evidence in humans is still limited, especially about the long-term benefits. It’s also unclear if the benefits of time-restricted eating are due to the timing itself or because people are eating less overall. When we looked at studies where participants ate freely (with no intentional calorie limits) but followed an eight-hour daily eating window, they naturally consumed about 200 fewer calories per day. <h2>What will work for you?</h2> In the past, clinicians have thought about weight loss and avoiding weight gain as a simile equation of calories in and out. But factors such as how we distribute our calories across the day, how often we eat and whether we eat late at night may also impact our metabolism, weight and health. There are no easy ways to lose weight. So choose a method, or combination of methods, that suits you best. You might consider <ul> <li>aiming to eat in an eight-hour window</li> <li>consuming your calories earlier, by focusing on breakfast and lunch</li> <li>opting for three meals a day, instead of six.</li> </ul> The <a href="https://link.springer.com/article/10.1007/s13679-024-00555-2">average adult gains 0.4 to 0.7 kg per year</a>. Improving the quality of your diet is important to prevent this weight gain and the strategies above might also help. Finally, there’s still a lot we don’t know about these eating patterns. Many existing studies are short-term, with small sample sizes and varied methods, making it hard to make direct comparisons. More research is underway, including well-controlled trials with larger samples, diverse populations and consistent methods. So hopefully future research will help us better understand how altering our eating patterns can result in better health.<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/242028/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/hayley-oneill-1458016">Hayley O'Neill</a>, Assistant Professor, Faculty of Health Sciences and Medicine, <a href="https://theconversation.com/institutions/bond-university-863">Bond University</a> and <a href="https://theconversation.com/profiles/loai-albarqouni-452476">Loai Albarqouni</a>, Assistant Professor | NHMRC Emerging Leadership Fellow, <a href="https://theconversation.com/institutions/bond-university-863">Bond 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/fasting-eating-earlier-in-the-day-or-eating-fewer-meals-what-works-best-for-weight-loss-242028">original article</a>. </div>

Body

Australians are having fewer babies and our local-born population is about to shrink: here’s why it’s not that scary

<div class="theconversation-article-body"><a href="https://theconversation.com/profiles/amanda-davies-201009">Amanda Davies</a>, <a href="https://theconversation.com/institutions/the-university-of-western-australia-1067">The University of Western Australia</a> Australians are having fewer babies, so many fewer that without international migration our population would be on track to decline in just over a decade. In most circumstances, the number of babies per woman that a population needs to sustain itself – the so-called <a href="https://www.who.int/data/gho/indicator-metadata-registry/imr-details/123">total fertility rate</a> – is 2.1. Australia’s total fertility rate dipped below 2.1 in the late 1970s, moved back up towards it in the late 2000s (assisted in part by an improving economy, better access to childcare and the introduction of the <a href="https://theconversation.com/what-the-baby-bonus-boost-looks-like-across-ten-years-81563">Commonwealth Baby Bonus</a>), and then plunged again, hitting a low of <a href="https://www.abs.gov.au/statistics/people/population/population-projections-australia/2022-base-2071#assumptions">1.59</a> during the first year of COVID. <hr /> <iframe id="CHdqj" class="tc-infographic-datawrapper" style="border: none;" src="https://datawrapper.dwcdn.net/CHdqj/3/" width="100%" height="400px" frameborder="0"></iframe> <hr /> The latest population projections from the Australian Bureau of Statistics assume the rate remains near its present 1.6% for <a href="https://www.abs.gov.au/statistics/people/population/population-projections-australia/2022-base-2071#assumptions">the next 50 years</a>. An alternative, lower, set of assumptions has the rate falling to 1.45 over the next five years and staying there. A higher set of assumptions has it rebounding to 1.75 and staying there. A comprehensive study of global fertility trends published in March in the medical journal <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00550-6/fulltext#%20">The Lancet</a> has Australia’s central case at 1.45, followed by a fall to 1.33 by the end of the century. Significantly, none of these assumptions envisages a return to replacement rate. The bureau’s central projection has Australia’s population turning down from 2037 in the absence of a boost from migration. <hr /> <iframe id="oi55c" class="tc-infographic-datawrapper" style="border: none;" src="https://datawrapper.dwcdn.net/oi55c/3/" width="100%" height="400px" frameborder="0"></iframe> <hr /> It’s easy to make guesses about reasons. Reliable contraception has been widely available for 50 years. Rents, mortgages and the other costs facing Australians of child-bearing age appear to be climbing. It’s still <a href="https://www.abc.net.au/news/2023-12-17/career-or-baby-michelle-battersby-pregnancy-gender-/103186296">difficult to have a career</a> if you have a child, and data show women still carry the substantive burden of <a href="https://theconversation.com/mind-the-gap-gender-differences-in-time-use-narrowing-but-slowly-191678">unpaid work around the home</a>. The US fertility rate has fallen <a href="https://ourworldindata.org/grapher/children-per-woman-un?tab=chart&time=1950..latest&country=OWID_WRL%7EUSA%7EAUS">much in line with Australia’s</a>. Reporting on <a href="https://theconversation.com/us-birth-rates-are-at-record-lows-even-though-the-number-of-kids-most-americans-say-they-want-has-held-steady-197270">research</a> into the reasons, Forbes Magazine succinctly said a broken economy had “<a href="https://fortune.com/2023/01/12/millennials-broken-economy-delay-children-birthrate/">screwed over</a>” Americans considering having children. More diplomatically, it said Americans saw parenthood as “<a href="https://fortune.com/2023/01/12/millennials-broken-economy-delay-children-birthrate/">harder to manage</a>” than they might have in the past. <h2>Half the world is unable to replace itself</h2> But this trend is widespread. The <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00550-6/fulltext#%20">Lancet study</a> finds more than half of the world’s countries have a fertility rate below replacement level. <a href="https://theconversation.com/chinas-population-shrinks-again-and-could-more-than-halve-heres-what-that-means-220667">China</a>, which is important for the global fertility rate because it makes up such a large share of the world’s population, had a fertility rate as high as 7.5 in the early 1960s. It fell to 2.5 before the start of China’s <a href="https://www.scmp.com/economy/china-economy/article/3135510/chinas-one-child-policy-what-was-it-and-what-impact-did-it">one-child</a> policy in the early 1990s, and then slid further from 1.8 to 1 after the policy was abandoned in 2016. <hr /> <iframe id="idC4X" class="tc-infographic-datawrapper" style="border: none;" src="https://datawrapper.dwcdn.net/idC4X/3/" width="100%" height="400px" frameborder="0"></iframe> <hr /> South Korea’s fertility rate has dived further, to the world’s lowest: <a href="https://time.com/6488894/south-korea-low-fertility-rate-trend-decline/">0.72</a>. The fertility rate in India, which is now <a href="https://www.un.org/development/desa/dpad/publication/un-desa-policy-brief-no-153-india-overtakes-china-as-the-worlds-most-populous-country/">more populous than China</a>, has also fallen <a href="https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?page=&locations=IN">below replacement level</a>. Most of the 94 nations that continue to have above-replacement fertility rates are in North Africa, the Middle East and Sub-Saharan Africa. Some, including Samoa and Papua New Guinea, are in the Pacific. Most of Asia, Europe and Oceania is already below replacement rate. <h2>A changing world order</h2> The largest high-fertility African nation, <a href="https://www.weforum.org/agenda/2020/09/the-world-population-in-2100-by-country/">Nigeria</a>, is expected to overtake China to become the world’s second-most-populous nation by the end of the century. But even Nigeria’s fertility rate will sink. The Lancet projections have it sliding from 4.7 to <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00550-6/fulltext#%20">1.87</a> by the end of the century. The differences mean the world’s population growth will increasingly take place in countries that are among the most vulnerable to environmental and economic hardship. Already economically disadvantaged, these nations will need to provide jobs, housing, healthcare and services for rapidly growing populations at a time when the rest of the world does not. On the other hand, those nations will be blessed with young people. They will be an increasingly valuable resource as other nations face the challenges of an ageing population and declining workforce. <h2>An older world, then a smaller world</h2> Global fertility <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00550-6/fulltext">halved</a> between 1950 and 2021, shrinking from 4.84 to 2.23. The latest projections have it sinking below the replacement rate to somewhere between 1.59 and 2.08 by 2050, and then to between <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00550-6/fulltext">1.25 and 1.96</a> by 2100. The world has already seen peak births and peak primary-school-aged children. In <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00550-6/fulltext">2016</a>, the world welcomed about 142 million live babies, and since then the number born each year has fallen. By 2021, it was about 129 million. The global school-age population aged 6 to 11 years peaked at around 820 million in <a href="https://www.un.org/development/desa/dpad/publication/un-desa-policy-brief-no-152-population-education-and-sustainable-development-interlinkages-and-select-policy-implications/">2023</a>. The United Nations expects the world’s population to peak at 10.6 billion in <a href="https://www.smh.com.au/national/the-planet-s-population-will-get-to-10-4-billion-then-drop-here-s-when-we-reach-peak-human-20231213-p5er8g.html">2086</a>, after which it will begin to fall. Another forecast, produced as part of the impressive <a href="https://www.healthdata.org/research-analysis/gbd">Global Burden of Disease</a> study, has the peak occurring two decades earlier in <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30677-2/fulltext">2064</a>, with the world’s population peaking at 9.73 billion. <h2>Fewer babies are a sign of success</h2> In many ways, a smaller world is to be welcomed. The concern common <a href="https://theconversation.com/a-long-fuse-the-population-bomb-is-still-ticking-50-years-after-its-publication-96090">in the 1960s and 1970s</a> that the world’s population was growing faster and faster and the world would soon be unable to feed itself has turned out to be misplaced. Aside from occasional blips (China’s birth rate in the <a href="https://www.jstor.org/stable/1973601">Year of the Dragon</a>) the fertility trend in just about every nation on Earth is downwards. The world’s population hasn’t been growing rapidly for long. Before 1700 it grew by only about <a href="https://ourworldindata.org/population-growth-over-time">0.4% per year</a>. By 2100 it will have stabilised and started to fall, limiting the period of unusually rapid growth to four centuries. In an important way, lower birth rates can be seen as a sign of success. The richer a society becomes and the more it is able to look after its seniors, the less important it becomes for each couple to have children to care for them in old age. This is a long-established theory with a name: the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4116081/">demographic transition</a>. For Australia, even with forecast immigration, lower fertility will mean changes. The government’s 2023 <a href="https://treasury.gov.au/publication/2023-intergenerational-report">Intergenerational Report</a> says that whereas there are now 3.7 Australians of traditional working age for each Australian aged 65 and over, by 2063 there will only be 2.6. It will mean those 2.6 people will have to work smarter, perhaps with greater assistance from artificial intelligence. Unless they decide to have more babies, which history suggests they won’t.<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/228273/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/amanda-davies-201009">Amanda Davies</a>, Professor and Head of School of Social Sciences, <a href="https://theconversation.com/institutions/the-university-of-western-australia-1067">The University of Western Australia</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/australians-are-having-fewer-babies-and-our-local-born-population-is-about-to-shrink-heres-why-its-not-that-scary-228273">original article</a>. </div>

Family & Pets

Why smart people prefer fewer friends

While we know that loneliness can be bad for our health, it seems that not everyone wants to be surrounded by a big group of friends. For those with a higher IQ, in fact, a smaller circle of friends is preferred. <a href="http://www.ncbi.nlm.nih.gov/pubmed/26847844">In their study of wellbeing</a> published in the British Journal of Psychology, researchers looked at what it is that makes people happy. Using a group of 15,000 people aged 18 to 28, they found that those living in more densely populated areas deemed themselves a being less satisfied with their quality of life. They then looked at the number of interactions the people had with their inner circle of friends, and it appeared that the more connections they made, the happier they reported being. However there was a significant exception to this ‘more is better’ approach to friendship. For those with the highest IQs, the correlation went the other way – they were less likely to claim to be satisfied with their quality of life if they were interacting with their friendship group more often. Does this sound familiar? Do you know some very smart people (or you may even be the smart one) who prefer to spend time on their own rather than being out and about with friends? It seems that for the super intelligent, spending time socialising can be seen as a missed opportunity to better oneself. Meaning that instead of going to a party or a film, they would prefer to spend time studying, reading, or partaking in activities that will help them achieve their own personal goals. These are the people who would stay home to study when everyone else was going on a road trip for the weekend. The person who started their own business and spent every spare minute they had on it. They would even miss special occasions as they were so caught up in what they were doing that they didn’t notice the time. So if you are on the receiving end of a ‘no thank you’ to your invitation to socialise from your high IQ pal, now you know not to take it personally. It’s not that they don’t see friendship as valuable and important, they just really value their own time and space to try and reach their goals. Have you noticed that your highly intelligent friends tend to socialise less? Or are you the smart one that tends to pull away in order to focus on your own pursuits? Image credits: Getty Images

Mind

Salt substitute leads to fewer strokes and heart attacks

<div class="copy"> A reduced-sodium, potassium-rich ‘salt substitute’ reduces rates of stroke, heart attack and death, according to a new <a rel="noreferrer noopener" href="https://doi.org/10.1056/NEJMoa2105675" target="_blank">study</a> published in The New England Journal of Medicine. Researchers from the George Institute for Global Health showed that a salt substitute with more potassium chloride and less sodium chloride – the ‘normal’ table salt – leads to lower blood pressure and reduced heart problems, with no harmful effects. “Almost everyone in the world eats more salt than they should,’’ says lead author Bruce Neal. “Switching to a salt substitute is something that everyone could do if salt substitutes were on the supermarket shelves. “Better still, while salt substitutes are a bit more expensive than regular salt, they’re still very low-cost – just a few dollars a year to make the switch. “As well as showing clear benefits for important health outcomes, our study also allays concerns about possible risks. We saw no indication of any harm from the added potassium in the salt substitute. Certainly, patients with serious kidney disease should not use salt substitutes, but they need to keep away from regular salt as well.” The study was conducted with 21,000 adults with a history of stroke or blood-pressure issues from 600 rural Chinese villages in 2014/15. For those using the low-sodium salt, the team found that incidents of stroke dropped by 14%, total cardiovascular events (including heart attack) dropped by 13% and premature deaths dropped by 12%. They also showed that the price difference between table salt and the substitute was low – $1.48 per kilogram for regular salt compared to $2.22 per kilogram for low-sodium salt. ‘’Last year, a modelling study done for China suggested that about 400,000 premature deaths might be prevented each year by national uptake of salt substitute,” says Neal. “Our results now confirm this. If salt was switched for salt substitute worldwide, there would be several million premature deaths prevented every year. “This is quite simply the single-most worthwhile piece of research I’ve ever been involved with. Switching table salt to salt substitute is a highly feasible and low-cost opportunity to have a massive global health benefit.” Because of this result, the researchers have urged salt manufactures to switch to low-sodium salt, and for governments to make policies that promote salt substitutes. Image credits: Shutterstock  <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=163351&title=Salt+substitute+leads+to+fewer+strokes+and+heart+attacks" alt="" width="1" height="1" />  </div> <div id="contributors"> This article was originally published on <a rel="noopener" href="https://cosmosmagazine.com/health/salt-substitute-fewer-strokes-heart-attacks/" target="_blank">cosmosmagazine.com</a> and was written by Deborah Devis. </div>

Body

"Pack of idiots": Businesses unhappy with Vic's fewer COVID-19 rules

<div class="post_body_wrapper"> <div class="post_body"> <div class="body_text redactor-styles redactor-in"> While Victorians have woken to more freedom after Melbourne Premier Daniel Andrews announced a range of restrictions were eased, many are still unhappy that the hospitality and retail industries have been left out. The new easement of restrictions include: <ul> <li>Melbourne residents are able to travel 25 kilometres from home</li> <li>No time limit on time spent outdoors</li> <li>Outdoor gatherings increased from five to 10 people from two households</li> <li>Skate parks, golf courses and tennis courts will reopen</li> <li>Melbourne residents are able to get a haircut, see an allied health professional, renovate their home, wash their car and bid at auction</li> </ul> “I have announced today what is safe but will not undermine the sacrifice, the hard work, the pain, the amazing efforts that Victorians have put in,” Andrews told reporters on Sunday. However, the hospitality, retail and beauty salon sector will remain closed for another two weeks until November 1. Business groups have since lashed out at Andrews' lockdown exit plan. Council of Small Business Organisations Australia chief executive Peter Strong told the ABC that Mr Andrews “talks to Victorians like they’re a pack of idiots” and had harmed businesses unnecessarily. “I think he’s never run a business. He thinks you turn the key and the shop opens again and everything happens,” he said. It’s not like that. And the lack of respect for the business community is profound.” Chapel Street Precinct general manager Chrissie Maus said it was an "unjust joke" to leave the sectors waiting until November 1. “There’s a cloud of anger from businesses…as this is no longer acceptable or sustainable for our businesses. I would have rather kept the 5km limit and the shops opened,” Ms Maus said. “This week the World Health Organization (WHO) stated they no longer support widespread city lockdowns. WHO understands we must now live with the virus until a vaccine is ready, Daniel Andrews does not. “It seems the rest of the country is evolving in their policies but Dan continues on his draconian parade. We must learn to live with the virus and open our businesses up now.” </div> </div> </div>

News

Why do fewer women die from coronavirus than men?

All over the world – in China, Italy, the United States and Australia – many <a href="https://globalhealth5050.org/covid19/">more men than women</a> are <a href="https://doi.org/10.1101/2020.03.24.20042903">dying from COVID-19</a>. Why? Is it genes, hormones, the immune system – or behaviour – that makes men more susceptible to the disease? I see it as an interaction of all of these factors and it isn’t unique to the SARS-Cov-2 virus – the different response of men and women is typical of many diseases in many mammals. The grim figures In <a href="https://globalhealth5050.org/covid19/">Italy and China</a> deaths of men are more than double those of women. In <a href="https://www1.nyc.gov/site/doh/covid/covid-19-data.page">New York city</a> men constitute about <a href="https://www.ny1.com/nyc/all-boroughs/news/2020/04/19/why-are-more-male-coronavirus-patients-dying-in-nyc-">61% of patients who die</a>. Australia is shaping up to have <a href="https://globalhealth5050.org/covid19/">similar results</a>, though here it’s mostly in the <a href="https://www.health.gov.au/news/health-alerts/novel-coronavirus-2019-ncov-health-alert">70-79 and 80-89 age groups</a>. <img style="width: 500px; height: 281.25px;" src="https://oversixtydev.blob.core.windows.net/media/7835699/senior-coronavirus-men-women.jpg" alt="" data-udi="umb://media/99b226d04fc34329baaf520d89009790" /> COVID-19 deaths in Australia (last updated April 19, 2020). <a href="https://www.health.gov.au/news/health-alerts/novel-coronavirus-2019-ncov-health-alert/coronavirus-covid-19-current-situation-and-case-numbers#current-status">Australian Government, Department of Health</a> One major variable in severity of COVID-19 is age. But this can’t explain the sex bias seen globally because the increased male fatality rate is the <a href="https://www.cebm.net/covid-19/global-covid-19-case-fatality-rates/">same in each age group from 30 to 90+</a>. Women also live on average <a href="https://www.who.int/gho/women_and_health/mortality/situation_trends_life_expectancy/en/">six years longer than men</a>, so there are more elderly women than men in the vulnerable population. The other major factor is the presence of chronic diseases, particularly <a href="https://www.hopkinsmedicine.org/health/wellness-and-prevention/special-heart-risks-for-men">heart disease</a>, <a href="https://www.bbc.com/news/health-15147999">diabetes</a> and <a href="https://canceraustralia.gov.au/about-us/news/mens-health-week-men-more-likely-develop-and-die-cancer">cancer</a>. These are all more common in men than women, which <a href="https://edition.cnn.com/2020/03/24/health/coronavirus-gender-mortality-intl/index.html">might account for some of the bias</a>. But then we must ask why men are more vulnerable to the diseases that put them at greater risk of COVID-19. Men and women are biologically different <a href="http://theconversation.com/what-makes-you-a-man-or-a-woman-geneticist-jenny-graves-explains-102983">Men and women differ</a> in their sex chromosomes and the genes that lie on them. Women have two copies of a mid-sized chromosome (called the X). Men have only a single X chromosome and a small Y chromosome that contains few genes. One of these Y genes (<a href="https://ghr.nlm.nih.gov/gene/SRY">SRY</a>) directs the embryo to become male by kick-starting the development of testes in an XY embryo. The testes make male hormones and the hormones make the baby develop as a boy. In the absence of SRY an ovary forms and makes female hormones. It’s the hormones that control most of the obvious visible differences between men and women – genitals and breasts, hair and body type – and have a large influence on behaviour. The Y chromosome and hormones The Y chromosome contains hardly any genes other than SRY but it is full of repetitive sequences (“junk DNA”). Perhaps a “toxic Y” could lose its regulation during <a href="https://link.springer.com/article/10.1186/s13293-018-0181-y">ageing</a>. This might hasten ageing in men and render them more susceptible to the virus. But a bigger problem for men is the male hormones unleashed by SRY action. Testosterone levels are implicated in many diseases, particularly heart disease, and <a href="https://www.health.harvard.edu/newsletter_article/mars-vs-venus-the-gender-gap-in-health">may affect lifespan</a>. Men are also disadvantaged by their <a href="https://dx.doi.org/10.1186%2Fs13293-017-0152-8">low levels of estrogen</a>, which protects women from many diseases, including heart disease. Male hormones also influence behaviour. <a href="https://www.open.edu/openlearn/science-maths-technology/science/biology/how-testosterone-affects-risk-taking-behaviour">Testosterone levels</a> have been credited with major differences between men and women in risky behaviours such as smoking and drinking too much alcohol, as well as reluctance to heed health advice and to seek medical help. The extreme differences in <a href="https://ourworldindata.org/smoking">smoking rate between men and women</a> in China (almost half the men smoke and only 2% of women) may help to account for their very high ratio of male deaths (more than double female). Not only is smoking a severe risk factor for any respiratory disease, but it also causes lung cancer, a further risk factor. Smoking rates are lower and not as sex-biased in many other countries, so risky behaviour can’t by itself explain the sex difference in COVID-19 deaths. Maybe sex chromosomes have other effects. Two X chromosomes are better than one The X chromosome bears more than 1,000 genes with functions in all sorts of things including routine metabolism, blood clotting and brain development. The presence of two X chromosomes in XX females provides a buffer if a gene on one X is mutated. XY males lack this X chromosome backup. That’s why boys suffer from many sex-linked diseases such as <a href="https://www.cdc.gov/ncbddd/hemophilia/facts.html">haemophilia</a> (poor blood clotting). The number of X chromosomes also has big effects on many metabolic characters that are separable from sex hormone effects, as <a href="https://doi.org/10.1371/journal.pgen.1002709">studies of mice reveal</a>. Females not only have a double dose of many X genes, but they may also have the benefit of two different versions of each gene. This X effect goes far to explain why <a href="https://dx.doi.org/10.1373%2Fclinchem.2018.288332">males die at a higher rate than females</a> at every age from birth. And another man problem is the immune system. We’ve known for a long time that <a href="https://dx.doi.org/10.1186%2F2042-6410-2-1">women have a stronger immune system than men</a>. This is not all good, because it makes women more susceptible to autoimmune diseases such as lupus and multiple sclerosis. But it gives women an advantage when it comes to susceptibility to viruses, as many <a href="https://dx.doi.org/10.4049%2Fjimmunol.1601166">studies in mice and humans</a> show. This helps to explain why men are more susceptible to many viruses, including SARS and MERS. There are at least 60 immune response genes on the X chromosome, and it seems that a higher dose and having two different versions of these gives women a broader spectrum of defences. Sex differences in diseases – the big picture Sex differences in the frequency, severity and treatment efficacy for many diseases were <a href="https://www.ncbi.nlm.nih.gov/books/NBK222288/">pointed out long ago</a>. COVID-19 is part of a larger pattern in which males lose out – at every age. This isn’t just humans – it is true of most mammals. Are sex differences in disease susceptibility simply the by-catch of genetic and hormone differences? Or were they, like many other traits, selected differently in males and females because of differences in life strategy? It’s <a href="https://doi.org/10.1111/2041-210X.13366">suggested</a> that male mammals spread their genes by winning competitions for mates, hence hormone control of risky behaviour is a plus for men. It’s also suggested female mammals are selected for traits that enhance their ability to care for young, hence their stronger immune system. This made sense for most mammals through the ages. So the sex bias in COVID-19 deaths is part of a much larger picture – and a very much older picture – of sex differences in genes, chromosomes and hormones that lead to very different responses to all sorts of disease, including COVID-19. Written by Jenny Graves. Republished with permission of <a href="https://theconversation.com/why-do-more-men-die-from-coronavirus-than-women-136038">The Conversation.</a>

Caring

Why Australians have fewer accents than other countries

There is clearly some variation in the way Australians speak, but for a big country it is strange the English-Australian accent hasn’t developed strong regional roots. The answer, say University of Melbourne experts, is less to do with geography and more to do with history. Australians have a long history of wanting to retain their British roots and ‘fit-in’ together – but technology also plays a part; access to a globalised media is continuing to smooth out what small differences there are. Senior voice lecturer at the Victorian College of the Arts, Leith McPherson says language is both a way to merge and differentiate yourself from social groups. “All accents are constantly changing but some are changing at a glacial rate because of their isolation,’’ she says. “In Australia, there just hasn’t been enough time or isolation in the 229 years since colonisation began for accents to become a location specific thing.” As well as being a younger country than the United States in terms of white settlement, an extra influence on the evolution of the Australian accent comes as a result of children. Dr Debbie Loakes, a phonetics expert at the School of Language and Linguistics, says the Australian accent levelled out very quickly after British colonisation, and experts believe that it was predominantly formed by children. Children, Dr Loakes says, are especially influenced by the way others speak, especially their fellow children which means they are more likely to all sound alike. “There’s a lot of push and pull as to whether or not you adopt the way someone else speaks,” says Dr Loakes. “Initially there would have been a lot of English accents coming together in the early years, and mainstream Australian English is thought to have its origins in the interactions between second generation children whose accents are thought to have “levelled out”. Just like one big melting pot, it started us off with relatively little variation in accent.” While indigenous Australians had developed over 250 different languages at the time of European colonisation, non-indigenous Australians simply haven’t been around long enough to develop regional accents. And as an English-speaking immigrant population, it was their common language that bound them together. “Australian accents instead tend to be more connected to social groups than geography. You adopt the accent of the group you want to blend with,” says Ms McPherson. Ms McPherson is well known for her work as a dialectic coach in the theatre and on films like Peter Jackson’s The Hobbit trilogy, which used J.R.R. Tolkien’s created languages. “One of the weird things that I do in my life is work with made-up languages, like Elvish or Dwarvish. But languages take time and regular use to become real and a population will change the way a language is used over time. That goes the same way for accents.” “So there is a sense that European Australians were, by choice or by necessity, creating a new world together. And in this new world, as in any population anywhere, you develop a cultural currency within the language,” says Ms McPherson. Then there’s the somewhat dated historical link to the Mother Country. “If you want to hang on to your British identity as my grandparents on my mother’s side did, they were Anglophiles, it was considered that people who spoke “correctly” were on the Received Pronunciation, or southern British, end of the Australian spectrum. And that has had a huge influence.’’ She says many of the people who arrived in Australia with other accents weren’t here by choice – circumstance led to it – so for the most part people were willing and wanting to leave their past behind. “More recently American influences are coming into the Australian accent much more so than British. So if you listen to Australian accent recordings from the 1950s, they are quite different, much more British than the average accent that you hear today,” she says. Professor John Hajek, a linguist from the School of Languages and Linguistics, says variations in Australian accents tend to reflect presumed social differences, not regional ones. “When you listen to an Australian it’s much harder to identify what their regional origin might be, but we’re very good at picking out what we assume to be the social characteristics of a speaker.” So is there an element of snobbery there? “Until the 1970s the cultivated Australian accent that was very common. It was the sort of accent you aimed for if you did speech and drama. It was meant to show you were cultivated, educated, and of high social status,” says Professor Hajek. “There was a lot of time spent coaching people, so if you talk to your mothers and your grandmothers, they will often talk to you about how they had elocution lessons, to make them sound more refined. But that has progressively disappeared and it has become quite unusual now.’’ Interestingly, Professor Hajek says the proportion of people who might identify as having a very broad Australian accent is also dropping. And that’s a direct result of mass media as well as mass university education. So although we all sound similar, there are variations – but for how much longer? “Linguists once talked about a three-way split in the Australian accent between broad Australian, general Australian and cultivated Australian, but even that is falling away now.” Written by Louise Bennet. Republished with permission of <a href="https://pursuit.unimelb.edu.au/" target="_blank">Pursuit</a>. Read the <a href="https://pursuit.unimelb.edu.au/articles/why-doesn-t-modern-australia-have-diverse-regional-accents" target="_blank">original article</a>. Image credit: Kath & Kim/ABC.

Books

Our Partners

Over 60

News

Shop

Catalogues

Contests

Entertainment

Travel

Health

Lifestyle

Finance

Property

Games

Information

Keep up to date