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7 ways you’re shortening the lifespan of your refrigerator

<p><strong>How you may be shortening the lifespan of a refrigerator</strong></p> <p>Refrigerators are a necessity in the home, but they cost a pretty penny. They can range in price from $700 to thousands of dollars, depending on which refrigerator brand you buy and which bells and whistles you want. Since it takes a good chunk of change to pay for this appliance, it makes sense to take great care of it so it lasts as long as possible. The typical lifespan of a refrigerator is 10 to 15 years, but it could last up to 20 years if you take superb care of it.</p> <p>Knowing how you may be shortening the life of your fridge helps you nip bad habits in the bud and make those well-spent dollars go the extra mile. That’s why we’ve rounded up the ways you may be knocking valuable time off your fridge’s life – read on and take note! Then, brush up on the signs your refrigerator is about to die and what your refrigerator temperature should be – both important things to know for fridge upkeep.</p> <p><strong>You’re not cleaning the internal mechanics</strong></p> <p>“If the defrost drain is clogged with debris, or frozen, the water dripping off the coils will overflow the drain trough and drip into the bottom of your refrigerator,” experts at the Repair Clinic told Reader’s Digest. Not only can this overwork your fridge, leading to a shorter lifespan, but it potentially causes your fridge/freezer to leak water all over your kitchen floor. </p> <p>Leaking water is a sign you should get any appliance looked at – it’s also a symptom of some of the ways you’re shortening the life of your washer and dryer.</p> <p><strong>You’re not cleaning the fridge itself</strong></p> <p>Additionally, debris, foodstuff, sticky spills and more common food mishaps that stay on the gasket of the refrigerator’s door too long can tear or break the seal of your refrigerator door. That can cause a leak, allowing cold air to escape. This makes learning how to clean your refrigerator properly all the more important (psst – these are the best fridge cleaners that’ll get the job done). </p> <p>To keep your fridge in tip-top shape as long as possible, wipe down the door edges often. And while you’re wiping down your fridge, see if you’ve organised your refrigerator the right way to keep ingredients fresh and avoid food poisoning.</p> <p><strong>You’re not cleaning the coils</strong></p> <p>More than 70 per cent of service calls for your fridge can be eliminated by cleaning your coils once a year – so experts recommend upping that to twice a year if you have furry pets (like an adorable but extra-fluffy pup). </p> <p>Debris on the coils can stop your fridge from properly dissipating heat, which means your compressor works harder and longer than it was designed to. That makes your fridge use more energy and shortens its lifespan.</p> <p><strong>It's too full </strong></p> <p>We’ve all played a few games of Tetris with our refrigerator after we get home with the groceries, but be careful when stocking up and storing. While this isn’t a huge problem with newer models, some older models have fan blades that are less protected. You may even be able to see the fan blades in your freezer or fridge.</p> <p>Cramming your food into the fridge and freezer to the point of applying undue pressure on this small part can affect its shape and fit among related parts of your fridge, risking a break. Ineffective fridges are overworked fridges, which will eventually lead to a refrigerator that doesn’t work. To avoid overfilling your fridge, do a deep clean of the contents of your fridge every once in a while and eliminate clutter.</p> <p><strong>You’re not changing the water filter often enough</strong></p> <p>If you have the type of fridge that makes ice – with the dispenser either within the freezer or on your door – the water filter is key to keeping this part of your refrigerator in great condition. An old, broken or dislodged water filter can create all kinds of problems for your fridge. At best, your ice dispenser breaks. At worst, your fridge overworks itself to an early death and you’re stuck footing the bill for a new one.</p> <p>Luckily, CNET reports that you likely can detect this problem early, as your ice cubes will start coming out smaller, oddly shaped or not at all. Keep this in mind next time you’re filling up your water bottle.</p> <p><strong>Your freezer temperature is too high</strong></p> <p>“Ideally, the temperature should be set -18 degrees Celsius,” said experts at Repair Clinic. The wrong freezer temperature can affect the longevity of your ice maker, as well as the safety of the food you’ll be eating. </p> <p>A temperature higher than -9 degrees Celsius can also cause the defrost thermostat to stop working, which, in turn, overworks your refrigerator and shortens its life.</p> <p><strong>You ignore weird noises or constant running</strong></p> <p>If you notice that your fridge is always running, or is running louder than usual, do something about it right away. Some fixes are easy enough that you can do them yourself, or they’re inexpensive for a professional, but even if that’s not the case, allowing a fridge to work itself harder than it is intended to is a good way to put an early expiration date on it. Depending on the age of your fridge, you may want to decide not to fix it and invest in a new, more energy- and cost-efficient option.</p> <p><em>Image credits: Getty Images</em></p> <p><em>This article originally appeared on <a href="https://www.readersdigest.co.nz/food-home-garden/7-ways-youre-shortening-the-lifespan-of-your-refrigerator" target="_blank" rel="noopener">Reader's Digest</a>. </em></p>

Home & Garden

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What your fitness level says about your lifespan

<p>Ever wish you had a crystal ball that could show you the future of your health? While the magic side of things might not be possible, recent research has found that there is a reliable indicator that can shed light on how you’ll be feeling as you enter your twilight years. That indicator? Physical activity, namely how much of it you’re doing during midlife.</p> <p>A study published in the Journal of the American Medical Association looked at almost 20,000 healthy men and women with a median age of 49 all of whom received a fitness rating between one and five (with one indicating very low levels of activity and five indicating very high levels). Twenty-six years later, the researchers followed up participants and found conclusively that the fitter they were in midlife, the lower their incidence of chronic conditions decades later.</p> <p>While the findings themselves weren’t hugely surprising, researchers were amazed at the impact cardio-respiratory fitness can have on preventing a large variety of illnesses, even those you wouldn’t usually associate with fitness.</p> <p>While maintaining a good level of fitness throughout your life is important, it’s never too late to make a change for the better. Improving your physical fitness is beneficial at any point in your life and there’s never been a better time to jump in. Here’s how!</p> <ol> <li>Make time for cardio – The general recommendation is that you integrate around 150 minutes of aerobic exercise into your week. That equates to around 20 to 30 minutes a day, five days per week. Walking, swimming, tennis, golf, Pilates and cycling are all great, low impact options.</li> <li>Build up – While it can be tempting to dive right in, starting slow and easing into a new program will help prevent injury and burn out from occurring. High intensity exercise after a period of inactivity won’t do your body any good and may scare you off for good. Start out steady and gradually increase over a period of weeks.</li> <li>Don’t forget to stretch – Yoga, Pilates and stretch classes are a fantastic way to integrate movement into your week while also keeping joints supple. Increasing your flexibility will also make other forms of exercise easier and lower your chances of injury.</li> </ol> <p><em>Image: Getty Images</em></p>

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Four ways having a pet increases your lifespan

<p>Pet owners will often swear their beloved pooch or moggie does wonders for their wellbeing, and now we have empirical proof. A <a href="https://www.nature.com/articles/s41598-017-16118-6">new study</a> has found dog ownership is linked to improved heart health for humans. This is an important finding, given heart disease is the <a href="http://www.who.int/mediacentre/factsheets/fs310/en/">leading cause of death</a> globally.</p> <p>While the new study focuses on dogs and heart disease, it raises the broader question of how pet ownership affects human longevity. Can pets create health in humans?</p> <p>A study known as the “blue zone” study has focused on factors affecting <a href="http://www.sciencedirect.com/science/article/pii/S0531556504002141">longevity</a> for over a decade. <a href="http://journals.sagepub.com/doi/abs/10.1177/1559827616637066#articleCitation">Nine factors</a> have been identified as increasing lifespan in the communities studied, and many of these factors are increased by pets.</p> <h2>1. Natural everyday movement</h2> <p>Much of the focus on pets providing health has been on dog walking. But anyone who owns a pet knows there are numerous incidental physical activities associated with pet ownership – like getting up to feed their pet; ensuring the pet’s food and water is available; and looking after pet “accommodation”.</p> <p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5491133/">Reducing prolonged sitting</a> and <a href="https://bmcpublichealth.biomedcentral.com/articles/10.1186/1471-2458-11-762">increasing incidental domestic activity</a> have both been shown to be protective with regard to health risks.</p> <p>Pets provide <a href="https://www.researchgate.net/profile/Marc_Suhrcke/publication/49784905_Judging_Nudging_Can_Nudging_Improve_Population_Health/links/0c96052bcb6a2b31d6000000.pdf">nudges</a> to everyday movement.</p> <p><a href="https://images.theconversation.com/files/202223/original/file-20180117-53295-isgsvi.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=1000&amp;fit=clip"><img src="https://images.theconversation.com/files/202223/original/file-20180117-53295-isgsvi.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip" alt="" /></a> <span class="caption">You must get out of bed so you can feed me.</span> <span class="attribution"><a href="https://unsplash.com/photos/gAAtlPqweaU" class="source">Unsplash/anthony de kroon</a>, <a href="http://creativecommons.org/licenses/by/4.0/" class="license">CC BY</a></span></p> <h2>2. Having a sense of purpose</h2> <p>At the very simplest level, pets can provide “<a href="https://lemosandcrane.co.uk/resources/RISE%20Pet%20ownership%20and%20mental%20illness.pdf">a reason to get up in the morning</a>”.</p> <p>This has been shown to be particularly important for groups at risk of, or experiencing, poorer health – including <a href="https://www.hindawi.com/journals/cggr/2014/623203/">the aged</a>, people with <a href="https://bmcpsychiatry.biomedcentral.com/articles/10.1186/s12888-016-1111-3?utm_campaign=BMC40562B&amp;utm_medium=BMCemail&amp;utm_source=Teradata">long-term mental illness</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3785224/">chronic diseases</a> (including <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1442-2018.2004.00207.x/full">youth</a>).</p> <p>Our (as-yet-unpublished) research interviewing older people about the impact of their pets on health has found pets could be protective against suicide. Pets are seen as reliant on their owners functionally (“need me to feed them or they will die”) and emotionally (“he would pine for me terribly”).</p> <p>Feeling unneeded and of no use has been identified as a key <a href="http://www.apa.org/science/about/psa/2009/06/sci-brief.aspx">risk factor</a> in suicide.</p> <h2>3. Regular destressing activities</h2> <p>Interaction with pets can reduce stress. There is evidence petting an animal may <a href="https://www.ncbi.nlm.nih.gov/pubmed/3236382">reduce heart rates</a>, and <a href="http://www.mayoclinicproceedings.org/article/S0025-6196(15)00674-6/abstract">co-sleeping with pets</a> may improve some people’s quality of sleep.</p> <p><a href="https://images.theconversation.com/files/202230/original/file-20180117-53302-1h9rmzc.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=1000&amp;fit=clip"><img src="https://images.theconversation.com/files/202230/original/file-20180117-53302-1h9rmzc.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip" alt="" /></a> <span class="caption">Some report they sleep better with a pet alongside them.</span> <span class="attribution"><a href="https://unsplash.com/photos/Wjx2hqdQfaQ" class="source">Unsplash/helena lopes</a>, <a href="http://creativecommons.org/licenses/by/4.0/" class="license">CC BY</a></span></p> <h2>4. Belonging and commitment</h2> <p>It’s in the area of relationships (three of the nine “blue zone” factors) that pets may have their most powerful role in longevity.</p> <p>Pets can act as a <a href="http://www.sciencedirect.com/science/article/pii/S0277953605000535?via%3Dihub">social catalyst</a>, promoting social connections, conversations, and even leading to the development of networks of practical support (a form of commitment).</p> <p>The connectivity of pets can even <a href="https://www.ncbi.nlm.nih.gov/pubmed/15970228">include non-pet owners</a>, as people feel safer in pet-owning neighbourhoods. Hence, pets can enable a sense of communal belonging identified as increasing longevity.</p> <p>The role pets play in mental health (as compared to physical health) may be where the strongest connection to individual longevity lies. There is an established <a href="https://www.medicalnewstoday.com/articles/269645.php">link between heart disease and mental unwellness</a>.</p> <p>Improving mental wellbeing (often through social enhancements) may be key in extending life expectancy, especially for population groups vulnerable to poor social connectedness. These groups often have <a href="http://content.time.com/time/health/article/0,8599,1863220,00.html">lower life expectancy</a>.</p> <p>People with <a href="https://bmcpsychiatry.biomedcentral.com/articles/10.1186/s12888-016-1111-3?utm_campaign=BMC40562B&amp;utm_medium=BMCemail&amp;utm_source=Teradata">long-term mental</a> illness, <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0057010">autism</a>, and the <a href="https://www.ncbi.nlm.nih.gov/pubmed/11111505">homeless</a> report their pets as providing nonjudgmental, simpler relationships than those with humans.</p> <p><a href="http://scholar.valpo.edu/cgi/viewcontent.cgi?article=1057&amp;context=jmms">Older people</a> report pets reducing loneliness and social isolation. Pets may improve vulnerable people’s interaction with others either <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0057010">directly</a> (improving social skills), or their social catalyst role can <a href="https://www.ncbi.nlm.nih.gov/pubmed/22329059">override social prejudice</a>.</p> <p><a href="https://images.theconversation.com/files/202225/original/file-20180117-53310-1ba1j56.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=1000&amp;fit=clip"><img src="https://images.theconversation.com/files/202225/original/file-20180117-53310-1ba1j56.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip" alt="" /></a> <span class="caption">Pets can provide opportunities to socialise.</span> <span class="attribution"><a href="https://www.flickr.com/photos/jimwallace57/5774338610/in/photolist-9NfZGf-9Ndd3g-9NeAGN-9Nh9hN-9NerCd-9Ndcei-9NeAW3-9Ndc8F-aYHjc2-nzyrkZ-mxoweR-uvctm5-9Neywj-N36NQC-9NdiRk-9Ngafo-oq3EB9-9Ng7P3-bAQXte-9NetKL-9Ndmze-6d4PTr-HJbA3z-9NeAM9-HHW51P-9NfY3L-4NE2B1-bnW7Fs-9NeyBh-9NbFAD-AjmH8X-9Ng46j-fiuENb-tzS4F-fVwHxo-bnW6MQ-9NfWvj-bAQXAv-9NdijV-Fq4xeL-efuLe6-RTjUxh-UShmbM-bE8DEv-nJ7doR-9NfYfm-Ah54dd-9NfXXq-z8gPDj-8THm5B" class="source">Flickr/Jim'sPhotos1</a>, <a href="http://creativecommons.org/licenses/by/4.0/" class="license">CC BY</a></span></p> <h2>Why we need to take pets and health seriously</h2> <p>In acknowledging people’s connection to their pets, we save lives. In <a href="https://habricentral.org/resources/43012/download/Save_me_Save_my_dog.pdf">disasters</a>, people die staying with, returning to, and trying to save pets. Disaster management planning is increasingly responding to and harnessing this reality, preventing deaths.</p> <p>It’s also being recognised <a href="http://shura.shu.ac.uk/13989/">women</a> stay with violent partners for fear of what will happen to pets. Pet-friendly escape options <a href="https://www.themorningbulletin.com.au/news/woman-who-couldnt-leave-pets-killed-violent-ex/3209238/">can save lives</a>.</p> <p>Public policies that <a href="https://theconversation.com/riding-in-cars-with-dogs-millions-of-trips-a-week-tell-us-transport-policy-needs-to-change-87094">support pet owners</a>, especially in <a href="https://academic.oup.com/jpubhealth/advance-article-abstract/doi/10.1093/pubmed/fdx111/4110317#.Wjwhx9shiCM.email">vulnerable groups</a>, have health-promoting outcomes.</p> <p>It’s important to remember animals are not “things” – they are living, breathing others. Simplistic understandings (“one pat of a pet per day”) risk endangering animals (overlooking their needs; abuse), and some humans (phobias, allergies).</p> <p>But for the millions of people who choose to have pets, often seeing them as family, increasing longevity is not the point. They add richness, creating lives worth living (longer) for.</p> <p><em>Anyone seeking support and information about suicide can contact Lifeline on 131 114 or beyondblue on 1300 22 46 36.</em><!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><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; text-shadow: none !important;" src="https://counter.theconversation.com/content/88640/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> <p><span><a href="https://theconversation.com/profiles/janette-young-129283">Janette Young</a>, Lecturer in Health Policy, Politics and Promotion, <em><a href="https://theconversation.com/institutions/university-of-south-australia-1180">University of South Australia</a></em></span></p> <p>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/four-ways-having-a-pet-increases-your-lifespan-88640">original article</a>.</p> <p><em>Image: Unsplash/jonathan daniels</em></p>

Family & Pets

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New study shows that animal's lifespan is written in its DNA

<p>Humans have a “natural” lifespan of around 38 years, according to a new method we have developed for estimating the lifespans of different species by analysing their DNA.</p> <p>Extrapolating from genetic studies of species with known lifespans, we found that the extinct woolly mammoth probably lived around 60 years and bowhead whales can expect to enjoy more than two and a half centuries of life.</p> <p>Our research, <a href="https://www.nature.com/articles/s41598-019-54447-w">published today in Scientific Reports</a>, looked at how DNA changes as an animal ages – and found that it varies from species to species and is related to how long the animal is likely to live.</p> <p><strong>The mystery of ageing</strong></p> <p>The ageing process is very important in biomedical and ecological research. As animals grow older, they experience a decline of biological functions, which limits their lifespan. Until now it has been difficult to determine how many years an animal can live.</p> <p>DNA is the blueprint of living organisms and it is an obvious place to seek insights into ageing and lifespan. However, no-one has been able to find differences in DNA sequences that account for differences in lifespans.</p> <p>Lifespans among vertebrates varies greatly. The pygmy goby (<em>Eviota sigillata</em>) is a small fish that lives only eight weeks, whereas individual Greenland sharks (<em>Somniosus microcephalus</em>) have been found that lived for more than 400 years.</p> <p>Knowing the lifespan of wild animals is fundamental for wildlife management and conservation. For endangered species, lifespan can be used to understand what populations are viable. In industries such as fisheries, lifespan is used in population models to determine catch limits.</p> <p>However, the lifespan of most animals is unknown. Most estimates come from a small number of individuals living in captivity whose ages at death were known. For long-lived species it is difficult to obtain a lifespan as they may outlive a generation of researchers.</p> <p><strong>Using changes in DNA to measure age</strong></p> <p>Over the past few years researchers have developed DNA “clocks” that can determine how old an animal is using a special type of change in the DNA called DNA methylation.</p> <p>DNA methylation does not change the underlying sequence of a gene but controls whether it is active. Other researchers have shown that DNA methylation in specific genes is associated with the maximum lifespan of some mammals such as primates.</p> <p>Despite DNA methylation being linked to ageing and lifespan, no research until now has used it as a method to estimate the lifespan of animals.</p> <p>In our research, we have used 252 genomes (full DNA sequences) of vertebrate species that other researchers have assembled and made publicly available in an <a href="https://www.ncbi.nlm.nih.gov/genome/">online database</a>. We then compared these genomes to <a href="https://genomics.senescence.info/species/">another database</a> of known animal lifespans.</p> <p>Using this data, we found that we could estimate the lifespan of vertebrate species by looking at where DNA methylation occurs in 42 particular genes. This method also lets us estimate the lifespans of long-lived and extinct species.</p> <p style="text-align: center;"><em><a href="https://images.theconversation.com/files/306222/original/file-20191211-95138-nfsxg8.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=1000&amp;fit=clip"><img src="https://images.theconversation.com/files/306222/original/file-20191211-95138-nfsxg8.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip" alt="" /></a> <span class="caption">Using DNA analysis, scientists can now estimate the lifespans of long-lived and extinct species.</span> <span class="attribution"><span class="source">CSIRO</span>, <span class="license">Author provided</span></span></em></p> <p style="text-align: left;"><strong>Extinct species</strong></p> <p>We found the lifespan of the bowhead whale, thought to be the world’s longest lived mammal, is 268 years. This estimate is 57 years higher than the oldest individual that has been found, so they may have a much longer lifespan than previously thought.</p> <p>We also found the extinct woolly mammoth had a lifespan of 60 years, similar to the 65-year span of the modern-day African elephant.</p> <p>The extinct Pinta Island giant tortoise had a lifespan of 120 years by our estimate. The last member of this species, Lonesome George, died in 2012 at age 112.</p> <p>Interestingly, we found Neanderthals and Denisovans, which are extinct species closely related to modern humans, had a maximum lifespan of 37.8 years.</p> <p>Based on DNA, we also estimated a “natural” lifespan modern humans of 38 years. This matches some anthropological estimates for early modern humans. However, humans today may be an exception to this study as advances in medicine and lifestyle have extended the average lifespan.</p> <p>As more scientists assemble the genomes of other animals, our method means their lifespans can readily be estimated. This has huge ecological and conservation significance for many species which require better wildlife management.<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><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; text-shadow: none !important;" src="https://counter.theconversation.com/content/128623/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: http://theconversation.com/republishing-guidelines --></p> <p><em><a href="https://theconversation.com/profiles/benjamin-mayne-908831">Benjamin Mayne</a>, Molecular biologist and bioinformatician, <a href="http://theconversation.com/institutions/csiro-1035">CSIRO</a></em></p> <p><em>This article is republished from <a href="http://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/a-new-study-shows-an-animals-lifespan-is-written-in-the-dna-for-humans-its-38-years-128623">original article</a>.</em></p>

Family & Pets

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How to work out how old your dog REALLY is

<p>If your dog has been alive and kicking its paws about for a decade, the widely held belief is that it has aged as much as a human would have done by the grand old age of 70. This conversion factor – each year of a dog’s life accounting for seven human years – comes from dividing human life expectancy of around 77 by the canine life expectancy of around 11.</p> <p>The underlying assumption is that each calendar year a dog lives though is equivalent to seven human years at any stage of a dog’s life. But <a href="https://www.biorxiv.org/content/10.1101/829192v1?ct=">new research</a> suggests that things aren’t so simple. And if we look at some basic developmental milestones, it’s clear why.</p> <p>For example, most dog breeds <a href="https://www.akc.org/expert-advice/health/sexual-maturity-in-puppies-what-to-expect/">reach sexual maturity</a> between the ages of six and 12 months – the upper end of that range corresponding, by the traditional conversion, to a human age of seven. And at the other end of the spectrum, although unusual, some dogs have been known to live for over 20 years. Under the “factor-of-seven” conversion rule, this would equate to an unfathomable 140 human-equivalent years.</p> <p>To make matters more complicated, dogs’ life expectancy depends significantly on the breed. Smaller dogs <a href="https://www.akc.org/expert-advice/health/why-do-small-dogs-live-longer/">tend to live significantly longer</a>, suggesting that they age more slowly than bigger dogs.</p> <p>All of this raises the question of what exactly we mean by age. The most obvious way to describe it is simply the length of time that has passed since birth. This is known as the chronological definition of age.</p> <p>However, there are other descriptions. “Biological age”, for example, is a more subjective definition, which relies on assessing physiological indicators to identify an indivdual’s development. These include measures like the “<a href="https://bmcgeriatr.biomedcentral.com/articles/10.1186/1471-2318-8-24">frailty index</a>” – surveys which take into account an individual’s disease status, cognitive impairments and levels of activity.</p> <p>Then there are the more objective <a href="https://academic.oup.com/biomedgerontology/article/56/4/B180/619965">ageing biomarkers</a>, such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4639797/">levels of gene expression</a> (genes produce proteins at differing rates at different stages of life) or <a href="https://academic.oup.com/biomedgerontology/article/56/4/B180/619965">numbers of immune cells</a>. The rate at which biological age increases depends on <a href="https://www.biorxiv.org/content/10.1101/578245v1.full">genetically inherited factors, mental health and lifestyle</a>.</p> <p>For example, if you’ve spent a lot of time eating junk food and smoking cigarettes instead of taking exercise and eating healthily, the chances are your biological age will exceed your chronological age. Or, you might be a 60-year-old with the body of a 40-year-old if you’ve looked after yourself well.</p> <p><strong>A new look at a dog’s life</strong></p> <p>When it comes to comparing animal ages across species, the biological definitions of age are far more useful than their chronological counterparts. Knowing a hamster is six weeks old doesn’t give you a good picture of that animal’s life stage even if you know the life expectancy of a hamster is only three years. Learning that a hamster has reached an age at which it can reproduce gives a much better picture of its level of maturity.</p> <p>The authors of the <a href="https://www.biorxiv.org/content/10.1101/829192v1?ct=">new ageing study</a> suggest that a sensible way to measure biological age is though so-called “epigenetic clocks” – changes to the packaging of our DNA that accumulate over time in all mammals.<span class="attribution"><a href="https://www.shutterstock.com/image-photo/old-lazy-mixed-breed-dog-prepares-8021299?src=c8957236-c3fe-4b09-a428-f14ae9f9c00a-1-48" class="source"></a></span></p> <p>In particular, “methylation” – the addition of methyl groups (a carbon atom bonded to three hydrogen atoms) to DNA – seems to be a good indicator of age. Many prominent physiological markers, such as the development of teeth, seem to occur at the same levels of methylation across different species. So by matching the levels of methylation in Labrador retrievers and humans, the researchers derived a formula to map dog age to its human equivalent.</p> <p>That formula is: human equivalent age = 16 x ln(dog’s chronological age) + 31.</p> <p>Here “ln” represents a <a href="https://www.rapidtables.com/calc/math/Ln_Calc.html">mathematical function</a> known as the <a href="https://www.britannica.com/science/logarithm#ref795970">natural logarithm</a>. The logarithm function is well-known in the non-linear scales for energy released during earthquakes (Richter) or for measuring sound (decibels). It comes in useful for measuring quantities whose sizes vary over many orders of magnitude. It’s even possible, as I explore in my new book <a href="https://amzn.to/2MkmdcM">The Maths of Life and Death</a>, that a logarithmic experience of the passing of time might explain why we perceive <a href="https://theconversation.com/why-time-seems-to-go-by-more-quickly-as-we-get-older-63354">time speeding up as we get older</a>.</p> <p>In the graph below, you can see how the natural logarithm works to convert the years a dog has lived (dog age) into the equivalent human age in the red dashed curve. The curve suggests that dogs mature extremely rapidly at first, but that their ageing then slows down, meaning that most of their lives are experienced as a form of protracted middle age.</p> <p>A handy short cut is to remember that the first dog year counts for 31 human years. Then, every time the dog’s chronological age doubles after that, the number of equivalent human years increases by 11. So eight calendar years represents three “doublings” (from one to two, two to four and then four to eight) giving a dog age equivalent of 64 (that’s 31 + 3x11).</p> <p>This useful approximation is plotted as the black curve on the conversion figure below. The green line represents the discredited factor-of-seven rule that suggests unrealistic ages at the higher end of the dog age spectrum.</p> <p><a href="https://images.theconversation.com/files/304278/original/file-20191128-178114-11gk665.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=1000&amp;fit=clip"><img src="https://images.theconversation.com/files/304278/original/file-20191128-178114-11gk665.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip" alt="" /></a> <span class="caption">The different ways of converting a dog’s age to the equivalent progression through a human life.</span> <span class="attribution"><span class="source">Kit Yates</span></span></p> <p>Most dog lovers will already have suspected that the human-to-dog age relationship is non-linear, having noticed that, initially, their pets mature much more quickly than the linear factor-of-seven rule suggests.</p> <p>A <a href="https://www.telegraph.co.uk/pets/news-features/calculate-dogs-age-human-years/">more sophisticated refinement</a> to the factor-of-seven rules has suggested that each of the dog’s first two years correspond to 12 human years while all subsequent years count for four human equivalents. The blue curve in the above figure, which represents this ad hoc rule, shows better agreement with the new logarithmic law.</p> <p>In practice the new molecular insights into human-to-dog age conversion encapsulated by the logarithmic law suggest that dogs move into middle age even more rapidly than most dog-owners would have suspected. It’s worth bearing in mind, when you find that Rex is reluctant to chase the ball like he once did, that he’s probably got more miles on the clock than you’ve been giving him credit for.<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><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; text-shadow: none !important;" src="https://counter.theconversation.com/content/127655/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: http://theconversation.com/republishing-guidelines --></p> <p><em><a href="https://theconversation.com/profiles/christian-yates-199844">Christian Yates</a>, Senior Lecturer in Mathematical Biology, <a href="http://theconversation.com/institutions/university-of-bath-1325">University of Bath</a></em></p> <p><em>This article is republished from <a href="http://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/are-dog-years-for-real-an-explanation-of-calculating-canine-age-127655">original article</a>.</em></p>

Family & Pets

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How stress can shorten your lifespan

<p><em><strong>Robin Bailey, Senior Lecturer in Psychological Therapies, University of Central Lancashire, explains how stress can significantly shorten your lifespan.</strong></em></p> <p>A recent study of over 60,000 US adults examined the link between perceptions of exercise and mortality. The researchers found something curious: people who worried about being less active than others were up to 71% more likely to die in follow up period 21 years later, regardless of their actual levels of physical activity or overall health.</p> <p>Inversely, believing you are getting enough exercise can lead to better health. In a study conducted by Harvard University, a group of hotel workers was told that their daily work fulfilled recommended exercise guidelines. A second group – the control group – was not given this information. After just one month, people in the informed group showed significant health improvements, including a ten point drop in systolic blood pressure and two pound weight loss (0.9kg). Waist-to-hip ratio also improved, as did body mass index. All of these changes were significantly greater than the changes in the control group.</p> <p><strong>Meta-stress</strong></p> <p>It is a commonly held belief that stress is bad for you, but the evidence is not clear cut. For example, a 2016 UK study of over <span style="text-decoration: underline;"><strong><a href="http://www.sciencedirect.com/science/article/pii/S0140673615010879" target="_blank">700,000 women</a></strong></span>, found that self-reported levels of stress had no direct effect on mortality.</p> <p>Similar to what has been found with activity levels, how you perceive or think about stress may be as big a problem as stress itself. A number of studies seem to support this idea.</p> <p>In a <span style="text-decoration: underline;"><strong><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3374921/" target="_blank">large study</a></strong></span>, spanning nine years, researchers explored the role of stress and its impact on health and mortality. In this study, the researchers not only explored people’s levels of stress, but also their beliefs about stress being dangerous for their health.</p> <p>The results showed that neither high amounts of stress nor the perception that stress has a negative effect on health were independently associated with premature death. However, people who both believed that stress affects health and reported a large amount of stress had a 43% increased risk of premature death. The authors concluded: “The results suggest that the appraisal of both the amount of stress and its impact on health may work together synergistically to increase the risk of premature death.”</p> <p>Interestingly, those who reported high levels of stress but who did not believe their stress was harmful, had the lowest mortality rates, even compared with those who had less stress.</p> <p><strong>New mindset</strong></p> <p>What links both these areas of research is the idea that your mindset may be very important in influencing both the positive and negative effects of stress and exercise. So how can you change your mindset?</p> <p>A starting point with exercise is to give up worrying how much physical activity you are doing compared with others. This is particularly important if your comparisons are based on unrealistically high standards, such as those often portrayed on social media.</p> <p>Follow public health guidelines on appropriate levels of physical activity, but remember to praise yourself for the exercise and activity you do, and don’t punish yourself for the exercise you don’t do. This may increase your motivation and provide a range of physical health benefits – as with the hotel workers.</p> <p>With regards to stress, you need to stop thinking of psychological stress as being directly dangerous, particularly if you are stressed, as it is the relationship between stress and its perceived effect on health that increases mortality. When people worry about stress being dangerous, it can lead to a range of behaviours that can be much more dangerous, such as smoking, binge eating and excessive alcohol consumption.</p> <p>Two approaches may be helpful here: first, don’t worry about stress being bad for you. Worry only heightens a sense of threat and strengthens the belief that stress is dangerous. By choosing not to worry, you can greatly reduce any stress you may have about stress. This may also reduce your desire to engage in unhealthy lifestyle choices.</p> <p>Second, accept stress as a normal part of life and a natural survival mechanism for dealing with threats. It has been shown that when people shift to seeing <span style="text-decoration: underline;"><strong><a href="http://goodthinkinc.com/wp-content/uploads/CrumSaloveyAchor_RethinkingStress_JPSP2013.pdf" target="_blank">stress as enhancing</a></strong></span> rather than debilitating, it can result in more positive outcomes.</p> <p>A change in perception and a reduction in worry may be a beneficial goal we can all achieve.</p> <p><em>Written by Robin Bailey. Republished with permission of <a href="http://www.theconversation.com" target="_blank"><strong><span style="text-decoration: underline;">The Conversation</span></strong></a>.</em><img width="1" height="1" src="https://counter.theconversation.com/content/88788/count.gif?distributor=republish-lightbox-advanced" alt="The Conversation"/></p>

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4 ways having a pet increases your lifespan

<p><em><strong>Dr Janette Young is a Lecturer in Health Policy, Politics and Promotion at the University of South Australia.</strong></em></p> <p>Pet owners will often swear their beloved pooch or moggie does wonders for their wellbeing, and now we have empirical proof. A <span style="text-decoration: underline;"><strong><a href="https://www.nature.com/articles/s41598-017-16118-6" target="_blank">new study</a></strong></span> has found dog ownership is linked to improved heart health for humans. This is an important finding, given heart disease is the <span style="text-decoration: underline;"><strong><a href="http://www.who.int/mediacentre/factsheets/fs310/en/" target="_blank">leading cause of death</a></strong></span> globally.</p> <p>While the new study focuses on dogs and heart disease, it raises the broader question of how pet ownership affects human longevity. Can pets create health in humans?</p> <p>A study known as the “blue zone” study has focused on factors affecting <span style="text-decoration: underline;"><strong><a href="http://www.sciencedirect.com/science/article/pii/S0531556504002141" target="_blank">longevity</a></strong></span> for over a decade. <span style="text-decoration: underline;"><strong><a href="http://journals.sagepub.com/doi/abs/10.1177/1559827616637066#articleCitation" target="_blank">Nine factors</a></strong></span> have been identified as increasing lifespan in the communities studied, and many of these factors are increased by pets.</p> <p><strong>1. Natural everyday movement</strong></p> <p>Much of the focus on pets providing health has been on dog walking. But anyone who owns a pet knows there are numerous incidental physical activities associated with pet ownership – like getting up to feed their pet; ensuring the pet’s food and water is available; and looking after pet “accommodation”.</p> <p><span style="text-decoration: underline;"><strong><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5491133/" target="_blank">Reducing prolonged sitting</a></strong></span> and <span style="text-decoration: underline;"><strong><a href="https://bmcpublichealth.biomedcentral.com/articles/10.1186/1471-2458-11-762" target="_blank">increasing incidental domestic activity</a></strong></span> have both been shown to be protective with regard to health risks.</p> <p>Pets provide <span style="text-decoration: underline;"><strong><a href="https://www.researchgate.net/profile/Marc_Suhrcke/publication/49784905_Judging_Nudging_Can_Nudging_Improve_Population_Health/links/0c96052bcb6a2b31d6000000.pdf" target="_blank">nudges</a></strong></span> to everyday movement.</p> <p><strong>2. Having a sense of purpose</strong></p> <p>At the very simplest level, pets can provide “<span style="text-decoration: underline;"><strong><a href="https://lemosandcrane.co.uk/resources/RISE%20Pet%20ownership%20and%20mental%20illness.pdf" target="_blank">a reason to get up in the morning</a></strong></span>”.</p> <p>This has been shown to be particularly important for groups at risk of, or experiencing, poorer health – including <span style="text-decoration: underline;"><strong><a href="https://www.hindawi.com/journals/cggr/2014/623203/" target="_blank">the aged</a></strong></span>, people with <span style="text-decoration: underline;"><strong><a href="https://bmcpsychiatry.biomedcentral.com/articles/10.1186/s12888-016-1111-3?utm_campaign=BMC40562B&amp;utm_medium=BMCemail&amp;utm_source=Teradata" target="_blank">long-term mental illness</a></strong></span> and <span style="text-decoration: underline;"><strong><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3785224/" target="_blank">chronic diseases</a></strong></span> (including <span style="text-decoration: underline;"><strong><a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1442-2018.2004.00207.x/full" target="_blank">youth</a></strong></span>).</p> <p>Our (as-yet-unpublished) research interviewing older people about the impact of their pets on health has found pets could be protective against suicide. Pets are seen as reliant on their owners functionally (“need me to feed them or they will die”) and emotionally (“he would pine for me terribly”).</p> <p>Feeling unneeded and of no use has been identified as a key <span style="text-decoration: underline;"><strong><a href="http://www.apa.org/science/about/psa/2009/06/sci-brief.aspx" target="_blank">risk factor</a></strong></span> in suicide.</p> <p><strong>3. Regular destressing activities</strong></p> <p>Interaction with pets can reduce stress. There is evidence petting an animal may <span style="text-decoration: underline;"><strong><a href="https://www.ncbi.nlm.nih.gov/pubmed/3236382" target="_blank">reduce heart rates</a></strong></span>, and <span style="text-decoration: underline;"><strong><a href="http://www.mayoclinicproceedings.org/article/S0025-6196(15)00674-6/abstract" target="_blank">co-sleeping with pets</a></strong></span> may improve some people’s quality of sleep.</p> <p><strong>4. Belonging and commitment</strong></p> <p>It’s in the area of relationships (three of the nine “blue zone” factors) that pets may have their most powerful role in longevity.</p> <p>Pets can act as a <span style="text-decoration: underline;"><strong><a href="http://www.sciencedirect.com/science/article/pii/S0277953605000535?via%3Dihub" target="_blank">social catalyst</a></strong></span>, promoting social connections, conversations, and even leading to the development of networks of practical support (a form of commitment).</p> <p>The connectivity of pets can even <span style="text-decoration: underline;"><strong><a href="https://www.ncbi.nlm.nih.gov/pubmed/15970228" target="_blank">include non-pet owners</a></strong></span>, as people feel safer in pet-owning neighbourhoods. Hence, pets can enable a sense of communal belonging identified as increasing longevity.</p> <p>The role pets play in mental health (as compared to physical health) may be where the strongest connection to individual longevity lies. There is an established <span style="text-decoration: underline;"><strong><a href="https://www.medicalnewstoday.com/articles/269645.php" target="_blank">link between heart disease and mental unwellness</a></strong></span>.</p> <p>Improving mental wellbeing (often through social enhancements) may be key in extending life expectancy, especially for population groups vulnerable to poor social connectedness. These groups often have <span style="text-decoration: underline;"><strong><a href="http://content.time.com/time/health/article/0,8599,1863220,00.html" target="_blank">lower life expectancy</a></strong></span>.</p> <p>People with <span style="text-decoration: underline;"><strong><a href="https://bmcpsychiatry.biomedcentral.com/articles/10.1186/s12888-016-1111-3?utm_campaign=BMC40562B&amp;utm_medium=BMCemail&amp;utm_source=Teradata" target="_blank">long-term mental</a></strong></span> illness, <span style="text-decoration: underline;"><strong><a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0057010" target="_blank">autism</a></strong></span>, and the <span style="text-decoration: underline;"><strong><a href="https://www.ncbi.nlm.nih.gov/pubmed/11111505" target="_blank">homeless</a></strong></span> report their pets as providing nonjudgmental, simpler relationships than those with humans.</p> <p><span style="text-decoration: underline;"><strong><a href="http://scholar.valpo.edu/cgi/viewcontent.cgi?article=1057&amp;context=jmms" target="_blank">Older people</a></strong></span> report pets reducing loneliness and social isolation. Pets may improve vulnerable people’s interaction with others either <span style="text-decoration: underline;"><strong><a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0057010" target="_blank">directly</a></strong></span> (improving social skills), or their social catalyst role can <span style="text-decoration: underline;"><strong><a href="https://www.ncbi.nlm.nih.gov/pubmed/22329059" target="_blank">override social prejudice</a></strong></span>.</p> <p><strong>Why we need to take pets and health seriously</strong></p> <p>In acknowledging people’s connection to their pets, we save lives. In <span style="text-decoration: underline;"><strong><a href="https://habricentral.org/resources/43012/download/Save_me_Save_my_dog.pdf" target="_blank">disasters</a></strong></span>, people die staying with, returning to, and trying to save pets. Disaster management planning is increasingly responding to and harnessing this reality, preventing deaths.</p> <p>It’s also being recognised <span style="text-decoration: underline;"><strong><a href="http://shura.shu.ac.uk/13989/" target="_blank">women</a></strong></span> stay with violent partners for fear of what will happen to pets. Pet-friendly escape options <span style="text-decoration: underline;"><strong><a href="https://www.themorningbulletin.com.au/news/woman-who-couldnt-leave-pets-killed-violent-ex/3209238/" target="_blank">can save lives</a></strong></span>.</p> <p>Public policies that <span style="text-decoration: underline;"><strong><a href="https://theconversation.com/riding-in-cars-with-dogs-millions-of-trips-a-week-tell-us-transport-policy-needs-to-change-87094" target="_blank">support pet owners</a></strong></span>, especially in <span style="text-decoration: underline;"><strong><a href="https://academic.oup.com/jpubhealth/advance-article-abstract/doi/10.1093/pubmed/fdx111/4110317#.Wjwhx9shiCM.email" target="_blank">vulnerable groups</a></strong></span>, have health-promoting outcomes.</p> <p>It’s important to remember animals are not “things” – they are living, breathing others. Simplistic understandings (“one pat of a pet per day”) risk endangering animals (overlooking their needs; abuse), and some humans (phobias, allergies).</p> <p>But for the millions of people who choose to have pets, often seeing them as family, increasing longevity is not the point. They add richness, creating lives worth living (longer) for.</p> <p>Written by Dr Janette Young. Republished with permission of <a href="http://theconversation.com/" target="_blank"><strong><span style="text-decoration: underline;">The Conversation</span></strong></a>.<img width="1" height="1" src="https://counter.theconversation.com/content/88640/count.gif?distributor=republish-lightbox-advanced" alt="The Conversation"/> </p>

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How mental illness impacts your lifespan

<p><em><strong>Dr Annette Erlangsen is a Visiting Fellow at the Centre for Mental Health Research at Australian National University.</strong></em></p> <p>Men who are diagnosed with a mental health condition can expect to live 10.2 years less than those who aren’t, according to our new research, published in <span style="text-decoration: underline;"><em><strong><a href="http://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(17)30429-7/fulltext" target="_blank">The Lancet Psychiatry</a></strong></em></span>. The life expectancy gap for women with mental illness is 7.3 years earlier those without.</p> <p>Despite efforts to address the issue, the gap has remained consistent over two decades. However the causes of death have changed: deaths from injury and suicide have decreased, while premature deaths from cancer and heart disease have doubled.</p> <p>My colleagues and I analysed medical and hospital data from Denmark over two decades to 2014. While our new study only looked at Danes, past research from Australia found <span style="text-decoration: underline;"><strong><a href="http://www.bmj.com/content/346/bmj.f2539" target="_blank">supportive results</a></strong></span>. In 2005, Australian men with a mental illness could expect to live 15.9 years less than men without mental illness. The gap was 12 years for Australian women.</p> <p>Our new study used a new mathematical approach to calculate life expectancy and life years lost, with more precision than previous research. This allowed us to examine the changes in the cause of death.</p> <p>The largest differences in early death between those with and without mental disorders were found for respiratory diseases, such as <span style="text-decoration: underline;"><strong><a href="https://theconversation.com/explainer-what-is-chronic-obstructive-pulmonary-disease-25539" target="_blank">chronic obstructive pulmonary disorders</a></strong></span> (known as “smoker’s lung”), and alcohol misuse. Deaths involving alcohol still account for the major share of the excess life years lost among people with mental disorders over the past two decades.</p> <p>Deaths due to suicide and accidents such as car crashes decreased slightly among people with mental illnesses over the past 20 years. These are, however, still major contributors to the life expectancy gap. This is partially related to the mental health disorders themselves, but also to less healthy lifestyles, which might involve high-risk behaviours, such as being under the influence of alcohol or other substances.</p> <p>Chronic diseases – such as cancer, diabetes and heart disease – are now playing a bigger role in the early death of people with mental health disorders. These people live longer than they used to and are therefore exposed to the risks of developing other age- and lifestyle-related disorders.</p> <p>People with mental disorders tend to live less healthy lives – in terms of diet, smoking, alcohol consumption, and physical exercise – than the rest of the population. <span style="text-decoration: underline;"><strong><a href="https://www.sane.org/mental-health-and-illness/facts-and-guides/antipsychotic-medication" target="_blank">Side-effects of anti-psychotic medication</a></strong></span>, such as weight gain, blurred vision and muscle spasms, can also have a significant impact on the lives of people with severe mental disorders.</p> <p><span style="text-decoration: underline;"><strong><a href="http://www.sciencedirect.com/science/article/pii/S0022395610001378?via%3Dihub" target="_blank">Physical conditions are sometimes overlooked</a></strong></span> in people with mental disorders and tend to be detected later than for other people. People with schizophrenia, for instance, are less likely to be treated for and more likely to die from heart disease.</p> <p>Clinicians rightly focus on the mental well-being of people with mental disorders, but more attention needs to directed toward their physical well-being. One way to ensure this occurs is to implement routine screening programs for chronic health conditions in mental health clinics and during admissions to mental health wards.</p> <p>We need to address the life expectancy gap by approaching mental illness more holistically, and consider the person’s whole health profile, including their lifestyle and the support they need. The health system can no longer simply prescribe medication and send the patient on their way.</p> <p><em>Written by Annette Erlangsen. Republished with permission of <a href="http://theconversation.com/" target="_blank"><strong><span style="text-decoration: underline;">The Conversation</span></strong></a>.<img width="1" height="1" src="https://counter.theconversation.com/content/88766/count.gif?distributor=republish-lightbox-advanced" alt="The Conversation"/> </em></p>

Mind

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How your height affects your lifespan

<p><em><strong>Bradley Elliott is a lecturer in physiology and biomedical science at the University of Westminster.</strong></em></p> <p>The tallest man in Europe, 7ft 7in former basketball player turned actor <span style="text-decoration: underline;"><strong><a href="https://www.theguardian.com/tv-and-radio/2017/feb/26/neil-fingleton-game-of-thrones-star-and-uks-tallest-man-dies-aged-36" target="_blank">Neil Fingleton</a></strong></span>, who played roles in Game of Thrones, and the X-Men and Avengers films, recently died aged just 36. Such early death in the excessively tall is not uncommon. Robert Wadlow, the world’s tallest person on record <strong><span style="text-decoration: underline;"><a href="http://www.guinnessworldrecords.com/world-records/tallest-man-ever" target="_blank">died at 22</a></span></strong>, and of the 10 tallest people ever recorded, the oldest died at 56. In people, height is <strong><span style="text-decoration: underline;"><a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0094385" target="_blank">negatively correlated with longevity</a></span></strong>; that is, taller individuals don’t tend to live as long. It’s kind of unfortunate that I’m both a researcher into ageing and 6ft 1in tall.</p> <p>While these are extreme examples, in the general population there also is a trend of greater height leading to reduced longevity. For example, <strong><span style="text-decoration: underline;"><a href="http://cebp.aacrjournals.org/content/early/2013/07/25/1055-9965.EPI-13-0305" target="_blank">taller woman</a></span></strong> are more likely to suffer from cancer in later, post-menopausal life. In a study of civil servants at Whitehall, height was noted as an excellent correlate with <strong><span style="text-decoration: underline;"><a href="http://jech.bmj.com/content/54/2/97.full" target="_blank">risk of cancer, stroke and cardiovascular disorders, and ultimately death</a></span></strong>.</p> <p>Yet it’s a noted rule of thumb in the biological sciences that <strong><span style="text-decoration: underline;"><a href="http://jeb.biologists.org/content/jexbio/208/9/1717.full.pdf" target="_blank">bigger species of mammals live longer</a></span></strong> – for example, elephants (lifespan: 40 to 75 years) and whales (35 to 110 years) – than smaller ones – for example, mice and rats (around 12 months). So why is height not associated with longer life spans in humans?</p> <p>As a researcher into ageing, for me the important question is why does height, such a useful day-to-day feature, and arguably an evolutionary advantage for our hunter-gatherer ancestors on the savannah, seem to count against us? There are two good hypotheses here, one arguing the case for nature and the other for nurture – but it may be that they are linked.</p> <p>On the nurture, environmental factors side of the argument, there has been a lot of research conducted recently on the idea that reduced calorie intake (eating less) can correlate with greater longevity. Essentially, faced with restricted quantities of available food, animals tend to live longer.</p> <p>We have found good evidence for this in <strong><span style="text-decoration: underline;"><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC23719/" target="_blank">worms</a></span></strong>, <strong><span style="text-decoration: underline;"><a href="https://www.ncbi.nlm.nih.gov/pubmed/3958810" target="_blank">mice</a></span></strong>, <strong><span style="text-decoration: underline;"><a href="https://www.ncbi.nlm.nih.gov/pubmed/11991408" target="_blank">dogs</a></span></strong>, <strong><span style="text-decoration: underline;"><a href="http://www.nature.com/articles/ncomms4557" target="_blank">monkeys</a></span></strong>, and there are even <strong><span style="text-decoration: underline;"><a href="https://www.ncbi.nlm.nih.gov/pubmed/15096581" target="_blank">suggestions of the same effect in humans</a></span></strong>. Indeed, children who lived through the Second World War and <strong><span style="text-decoration: underline;"><a href="http://webarchive.nationalarchives.gov.uk/20160105160709/http:/www.ons.gov.uk/ons/rel/population-trends-rd/population-trends/no--145--autumn-2011/ard-pt145-golden-generation.pdf" target="_blank">rationing show a bump in longevity statistics</a></span></strong>. Why does this matter? Because these calorie restricted worms, mice, monkeys and children are also shorter than their well-feed peers. So average height across a population is a rough marker of calorie availability during childhood and development, which is a factor that decides height in adulthood.</p> <p>On the nature side of the argument, it might seem obvious but genetics dictates height as well. Even my above average height makes me the shortest member of my family, with a brother, mother and father who are all taller than me. So-called “familial height” is passed on via genes that contribute to height.</p> <p>In particular, the conveniently named and easy to remember gene Forkhead family, O subclass, type 3 gene (FOXO3), has a common variation that is associated with longevity in <strong><span style="text-decoration: underline;"><a href="https://www.ncbi.nlm.nih.gov/pubmed/18358814?dopt=Abstract&amp;holding=npg" target="_blank">worms</a></span></strong>, in <strong><span style="text-decoration: underline;"><a href="https://www.ncbi.nlm.nih.gov/pubmed/19627267?dopt=Abstract&amp;holding=npg" target="_blank">flies</a></span></strong>, and in <strong><span style="text-decoration: underline;"><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2544566/" target="_blank">human centenarians</a></span></strong>.</p> <p>This gene has many roles, contributing to stem cell activation, controlling cell death mechanisms, and altering the effectiveness of insulin and insulin-like growth factors. All of these play a role in how the body senses how much energy it has, and so how much growth it can afford over and above the nutrients and energy the body needs just to maintain itself. So variation in this FOXO3 gene may also contribute to this hypothetical connection between longevity, height and calories by directing more or less energy into growing the body.</p> <p>So while tallness is linked to shorter lifespans on average, we don’t really understand why. There’s some good research at the moment regarding both genetics and lifestyle, which may reveal that simply eating a little less over the course of your life may lead to a longer life. A simple sounding fix – but getting people to eat less has not always proven easy.</p> <p><em>Written by Bradley Elliott. First appeared on <a href="https://theconversation.com" target="_blank"><strong><span style="text-decoration: underline;">The Conversation</span></strong></a>. </em></p>

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Maximum human lifespan has been revealed

<p>We’re always hearing incredible stories of people surpassing the age of 100 (and even 110), but researchers suggest we shouldn’t expect to live much further beyond that. According to scientists at the Albert Einstein College of Medicine in New York, humans have already reached their potential when it comes to ageing.</p> <p>“The chances are very high that we [have] really reached our maximum allotted lifespan for the first time,” Jan Vijg, co-author of <a href="http://www.nature.com/nature/journal/vaop/ncurrent/full/nature19793.html" target="_blank"><strong><span style="text-decoration: underline;">the report</span></strong></a>, told <a href="https://www.theguardian.com/science/2016/oct/05/human-lifespan-has-hit-its-natural-limit-research-suggests" target="_blank"><strong><em><span style="text-decoration: underline;">The Guardian</span></em></strong></a>.</p> <p>The oldest person ever recorded was one Jeanne Louise Calment, who passed away in 1997 at the impressive age of 122 years old – but according to Vijg and his colleagues, it’s highly unlikely that she’ll be knocked off the top spot any time soon.</p> <p>Researchers studied data from 41 countries around the world from the Human Mortality Database and found that even though humans are living longer than ever before, thanks to better healthcare, medicines and vaccines, surviving beyond 100 years old is no mean feat. “[For] the oldest old people, we are still not very good at reducing their mortality rates,” Vijg explained.</p> <p>In addition, many nations have reached a sort of life expectancy plateau, with 88 per cent of countries not reporting a significant improvement in longevity since 1980 and many essentially stalling in the 1990s. “Based on the data we have now, the chance that you will ever see a person of 125 [years] in a given year is about 1 in 10,000.”</p> <p>However, associate dean for ageing at Newcastle University Tom Kirkwood believes otherwise. “There is no set programme for ageing and we know that the process, which is ultimately driven by the build-up of faults and damage in the cells and organs of the body, is to some degree malleable,” he told <em>The Guardian</em>. “Even without any change in the biology of ageing, it is almost inevitable that the current record will be broken.”</p> <p>Here's hoping! Tell us in the comments below, who’s the oldest person you’ve ever known?</p> <p><strong>Related links:</strong></p> <p><a href="/news/news/2016/10/top-5-relaxing-activities-according-to-science/"><span style="text-decoration: underline;"><em><strong>Top 5 relaxing activities, according to science</strong></em></span></a></p> <p><a href="/news/news/2016/09/5-foods-a-nutritionist-would-never-let-you-eat/"><strong><span style="text-decoration: underline;"><em>5 foods a nutritionist would never let you eat</em></span></strong></a></p> <p><a href="/news/news/2016/09/why-women-need-more-sleep-than-men/"><em><span style="text-decoration: underline;"><strong>The reason why women need more sleep than men</strong></span></em></a></p>

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