Ageing isn’t just about how many birthdays you’ve had, but about how well your body is actually functioning at a cellular level.
That’s something scientists call biological age. Two people who are exactly the same age can be ageing at totally different speeds, and a surprising number of everyday habits play a role in that difference. Researchers have been using something called epigenetic clocks, tests that measure tiny chemical changes in DNA, to work out which habits speed up ageing and which ones help slow it down. Here’s what they’ve found, and where you might be unknowingly going wrong.
Pushing your workouts too hard can backfire.
Regular exercise helps fight biological ageing, largely because it reduces damaging stress inside the body. But a study following 11,000 same-sex twins over 45 years found that people who exercised far too much showed signs of accelerated ageing, just like those who barely exercised at all.
One exercise physiologist explains that too much intense exercise without enough recovery time can raise chronic inflammation and place ongoing strain on muscles and joints. A rough split of 80% lower intensity exercise alongside 20% higher intensity work tends to allow for proper recovery while still supporting a healthy immune system.
Walking slowly may be quietly ageing you.
As we get older, the protective caps at the end of our chromosomes, called telomeres, naturally shorten, which is considered a genetic marker of biological ageing. Poor diet, smoking, drinking, and inactivity all make this shortening worse, but researchers studying genetic data from over four hundred thousand British adults found that picking up your walking pace can help offset some of that damage.
Their research found that walking briskly, defined as at least a hundred steps per minute, every day was linked to up to fifteen years of greater life expectancy. Even just ten minutes of brisk walking daily made a measurable difference.
Expensive supplements may not be worth the money.
If you’re spending a small fortune on premium supplements each month, a much cheaper daily multivitamin might actually do more for your biological age. One trial involving nearly a thousand healthy older adults tested different combinations of cocoa extract, multivitamins and placebos over two years.
The results, published this year, showed that taking a daily multivitamin slowed biological ageing by around four months based on several DNA-based measurements. The benefits were strongest among participants whose blood tests suggested they were already ageing faster than average when the study began.
Too much time in the sun affects more than just your skin.
Spending long stretches under strong sun doesn’t just speed up visible skin ageing. It’s also been linked to higher markers of biological ageing in people over fifty. Researchers analysed blood samples from 3,600 people alongside six years of local weather data around their homes.
They found that for every two hundred days of extreme heat exposure over that 6-year period, participants’ biological age increased by around three and a half months. Older adults are particularly vulnerable since the skin’s natural cooling system, which relies on sweat evaporating, becomes less effective with age, a decline that starts in your forties and becomes more noticeable by your sixties.
Skipping yogurt could mean missing out on a small but real benefit.
Plain yogurt is already known to support gut health, but it may also help slow biological ageing specifically. In one study, a group of overweight men added around seven tablespoons of plain yogurt to their daily diet, while also cutting back on processed food and adding light exercise three times a week.
Over twelve weeks, researchers found the yogurt eaters’ biological ageing slowed by roughly 2%, and this effect held up independently of any weight loss, suggesting the yogurt itself made a difference rather than the added activity alone.
Worrying about getting older can speed the process up.
Long term psychological stress can influence how genes switch on and off, which in turn affects how quickly the body ages at a cellular level. One researcher analysed mood data from over seven hundred women, then tested their blood to see whether anxiety about ageing actually sped up cellular ageing itself.
The results showed that higher anxiety about growing older was linked to faster biological ageing, with the strongest effect seen among women who also had specific health related fears. This suggests ageing anxiety isn’t purely psychological, it can leave a physical mark on the body too.
Chasing exactly eight hours of sleep might not be the goal.
Eight hours has long been treated as the gold standard for sleep, but new research suggests that being too fixated on hitting that exact number isn’t necessarily helpful. A large study of almost 500,000 middle-aged people in Britain found that both too little sleep, under six hours regularly, and too much, over eight hours, were linked to conditions like diabetes and depression, alongside faster ageing overall.
Those who typically slept somewhere between six and a half to just under eight hours a night showed the slowest rates of biological ageing across their organs. The lead researcher explained that getting enough sleep, without overdoing it, helps maintain a healthy balance across the body’s metabolism and immune system.
Difficult relationships can slowly but surely wear you down.
Strong friendships generally support healthy ageing, lowering the risk of cognitive decline and reducing depression. But research funded by a US ageing institute found that up to a third of people have at least one consistently difficult person in their life—someone who regularly creates problems or adds stress.
Spending a lot of time around these draining relationships can raise chronic stress levels and biological markers linked to faster ageing. The effect grows stronger with each additional difficult relationship, and becomes especially pronounced when that person is a family member rather than a friend.
Skipping the floss carries a bigger cost than you’d think.
Gum disease often starts as a fairly painless annoyance, but left unchecked, it can trigger ongoing inflammation throughout the body linked to a long list of health problems, from dementia and type 2 diabetes to heart and lung disease. That same chronic inflammation has also been connected to faster biological ageing overall.
A dental specialist explains that cleaning properly between your teeth, using floss or interdental brushes, needs to actually reach the sides of each tooth to be effective. Keeping a range of different sized interdental tools on hand tends to give the best, most thorough clean.
Cutting carbs too aggressively might not be doing you any favours.
Shifting toward more wholesome carbohydrates and slightly less animal protein could help lower your biological age, according to research involving adults in their sixties and seventies. Participants who made this kind of dietary shift saw a measurable reduction in their estimated biological age within just four weeks.
The biggest improvement came from an approach where more than half of daily calories came from carbohydrates found in fruit, vegetables and wholegrain, alongside around 14% from protein, much of it plant based. The researcher behind the study was careful to note it’s still too early to say definitively that this extends lifespan, but called it an early, promising sign.
That nightly glass of wine adds up more than you’d expect.
Alcohol directly damages DNA within telomeres, according to researchers at Oxford University, contributing to faster cellular ageing over time. Their research found that drinking around 29 units a week, roughly one large glass of wine each night, was linked to one to two years of accelerated ageing compared with drinking under six units weekly.
A representative from an alcohol charity described the findings as showing clear links between drinking and ageing. The advice from researchers is straightforward, building in at least a few completely alcohol-free nights each week appears to make a real difference.
