2026年1月30日
Why Your Genes Don’t Always Dictate How Long You’ll Live
Your daily habits play a huge part in your longevity
For years, lifespan has been linked to genetics. It feels as though some families seem to live long, healthy lives while others are burdened with illness.
But genetics, which refer to the DNA you inherit at birth that influences traits such as height and eye colour, are just part of the puzzle. In fact, research suggests that genetics account for only around 20 to 30% of your lifespan. Twins are a great example here as they share the same DNA, yet as they get older, one of the twins might develop dementia, whereas the other develops cardiovascular disease.
Longevity is actually a little more flexible than you may think because your lifestyle and behaviours play a big role. These factors shape your epigenetics, the biological switches that essentially turn genes 'on’ or ‘off’. These switches respond to a number of different things, from the foods you eat, your movement levels, stress and sleep.
So, while your genetics set the baseline chances of a long, healthy life, epigenetics shapes this. There are some stand out factors influencing how you age.
But genetics, which refer to the DNA you inherit at birth that influences traits such as height and eye colour, are just part of the puzzle. In fact, research suggests that genetics account for only around 20 to 30% of your lifespan. Twins are a great example here as they share the same DNA, yet as they get older, one of the twins might develop dementia, whereas the other develops cardiovascular disease.
Longevity is actually a little more flexible than you may think because your lifestyle and behaviours play a big role. These factors shape your epigenetics, the biological switches that essentially turn genes 'on’ or ‘off’. These switches respond to a number of different things, from the foods you eat, your movement levels, stress and sleep.
So, while your genetics set the baseline chances of a long, healthy life, epigenetics shapes this. There are some stand out factors influencing how you age.
Stress
A tough day at work or a falling out with a friend can cause you to feel stressed and worried, but it’s the chronic, relentless stress that causes issues. Research has found that exposure to stress can cause inflammation and damage to DNA in cells, which then accelerates aging. But, the good news is that by removing the stress, your body can recover.
Movement
Sedentary lifestyle? It’s time to get moving. Whether it’s daily walks, weight lifting or gym classes, it’s vital to move your body. If you avoid movement, research states that it could accelerate your loss of both cardio fitness and strength by a huge 25 to 30 years! In fact, 80-year-olds who have moved their whole life, are fitter and stronger than 50-year-olds who spend most of their time sitting.
Nutrition
Diets rich in whole foods (think fresh fruit, veg, meat, fish and eggs) fibre and healthy fats are linked to epigenetic markers associated with longer, healthier lives,
On the flip side, if your diet is high in processed foods and excess sugar, then ageing is accelerated. A study even found that for every 10% increase in daily calories from ultra-processed foods (think cakes, crisps, pastries, chocolate and processed meats), people were about two to three months biologically older. If one person got 40% of their calories from ultra-processed foods and another got 60%, the group eating more could be around half a year older, biologically.
On the flip side, if your diet is high in processed foods and excess sugar, then ageing is accelerated. A study even found that for every 10% increase in daily calories from ultra-processed foods (think cakes, crisps, pastries, chocolate and processed meats), people were about two to three months biologically older. If one person got 40% of their calories from ultra-processed foods and another got 60%, the group eating more could be around half a year older, biologically.
Sleep
The odd night of bad sleep won’t cause you harm, but poor sleep over many years can cause brain ageing, according to research, which is linked to issues such as dementia. Getting seven to nine hours each night, aiming to have a consistent sleep and wake time and also getting good quality sleep, with minimal disruptions, will support your longevity.
Knowing that your longevity can be influenced by your lifestyle choices, puts you in the driving seat. While your genes will play a role, it’s important to remember that just because your parents or family members lived long lives, it may not mean you will, so sticking to healthy lifestyle habits is still important.
Knowing that your longevity can be influenced by your lifestyle choices, puts you in the driving seat. While your genes will play a role, it’s important to remember that just because your parents or family members lived long lives, it may not mean you will, so sticking to healthy lifestyle habits is still important.
