Why do some people live to 100+? Is it down to lifestyle choices, to our genes or to something else? 

More and more people are living to 100. This includes 13,780 in the UK in 2013, rising to 14,570 in 2015. 

And one in three British babies born today is now expected to live to 100.

Is it all in our genes?

Studies have shown that exceptional longevity (reaching 100+) is linked to a certain gene, apolipoprotein E (ApoE). This is a protein that transports fats, such as cholesterol and triglycerides, around our body. 

Our bodies need both cholesterol and trigylcerides to function normally but too much of either increases the risk of heart attack and stroke.

No one has the same ApoE code. You inherit different ones from each of your parents. However, research suggests that certain combinations in our genetic makeups contribute to exceptional longevity.

And in particular genes related to our cardiovascular system have been implicated in exceptional longevity 

Large scale research in the US concludes, ‘Genes play a critical and complex role in facilitating exceptional longevity. The genetic influence becomes greater and greater with older and older ages, especially beyond 103 years of age.’

A study of the genetic determinants of extreme human longevity published in 2017 identified new rare variants in chromosomes 4 and 7. These were associated with extreme longevity and with reduced risk for cardiovascular disease and Alzheimer's disease.

These results confirm that the combinations of common genes and rare variants are associated with extreme longevity and a longer health span.

Does epigenetics play a role? 

Our genes can sometimes be switched on, switched off or modified by epigenetic factors, such as changes in our diet, environment, ect.

Maternal diet, early nutrition, and gut microbiota during the pregnancy may influence how long we live in good health, even if it may not be enough to help us live to 100. Research has shown that the epigenetics influence and involved in the process long and healthy life. 

Does gender matter?

Recent research shows that the gap between men and women’s longevity is beginning to decline due to improvements in mortality for men, now fewer than 5 women for every man reaches 100, down from 8 women to 1 man in 2002– updated statistics from Office of National Statistics.  

Reports have also shown that women who have children naturally later in life are more likely to live to be a centenarian.

It is thought that having a child later in life is a sign that the reproductive system and, therefore, the rest of the body is ageing slowly. 

What about a healthy lifestyle? 

Keeping yourself healthy is always important but centenarians may be more committed to living a healthy lifestyle:

  • In recent times centenarians have even begun to participate in sporting competitions worldwide, becoming icons of healthy ageing and provide evidence that it is never too late to start exercising, as regular exercise may combat the deleterious effects of ageing. 
  • Very few centenarians are obese. In fact, according to a major US study, most men are quite lean and nearly all have never smoked.  
  • A healthy lifestyle (physical activity and not smoking) is one factor that helps maintain good health as we get older. That’s according to an 18 year study of adults age 75+ in Sweden. The study also suggested that participation in at least one leisure activity and a social network also helped.
  • Physical exercise is also a route to mental stimulation and social opportunities. Interviews with Canadian centenarians revealed how important they felt this was for successful ageing. 
  • Research in China suggests that proximity to more green space is associated with increased longevity. This may be because it encourages exercise, is good for mental health and reduces exposure to air pollution.
  • The gut microbiota has been proposed as a promising factor influencing human health. A study published in 2019 on the role that gut health played in the lives of a group of Sardinian Centenarians confirmed that Centenarians had a higher diversity of core microbiota species and microbial genes than those in the young and elderly. This suggests that gut microbiota intervention directed at limiting gut inflammation and pathology may enhance healthy ageing and longevity. 
  • As we report elsewhere on Age Watch, Loma Linda in California is an interesting case study. A combination of exercise, vegetarian food, not smoking, eating nuts, social support and church attendance are believed to help explain why they tend to live 4 -7 years longer than other Californians.  

Is it the way you are? 

  • A positive approach to life and being sociable seem common traits amongst centenarians. This suggests that personality is a key factor in longevity
  • Having a purpose in life was mentioned as a factor by Canadian centenarians interviewed by researchers. Social isolation, loneliness in older people in contrast pose health risks, according to the National Institute on Ageing.
  • Centenarians seem to be able to handle stress better than most people. In one study oxidative stress (OE) levels were lower in centenarians than in younger elderly, and the lower the OE grade, the higher the likelihood of being centenarian. It is likely that this can slow down ageing, as being adaptable can help you manage stress better.
  • The Longevity Project suggests that being conscientious is the key to a long life. The hypothesis is that conscientious people are less prone to leading risky lives. They also seem biologically predisposed to live longer (possibly due to different levels of the chemical serotonin in the brain – believed to affect our mood, social behavior, appetite, digestion, sleep and memory). And they ‘find their way to happier marriages, better friendships and healthier work situations’ with all the attendant health benefits. 

Is it the world in which they lived? 

Are centenarians today coming from a generation of people who lived with fewer comforts and less exposure to the potentially harmful effects of modern technology? 

  • Born in or before 1915 they came into a world with few cars on the roads – although often with high levels of industrial pollution
  • Our modern day wireless devices all emit microwave radiation and there are reports that heavy mobile phone use can possibly increase the chance of developing illnesses, such as brain cancer. 
  • Perhaps more importantly, we live in what some health experts have described as an increasingly obesogenic environmentCalorie dense fast food, sugary drinks and snacks are available all around us if we live in cities. Physically demanding occupations have largely been replaced by work sitting down. And where people would once have walked (for instance to school as children) cars are increasingly used. 

Do you really want to live to 100?

Centenarians will live beyond many of their friends, family and even children. So this can be potentially isolating and lonely. 

However, many centenarians attribute their life span to maintaining close ties with people, suggesting again that personality is an important factor. 


You can’t do much about the genes you inherit or your gender, two key factors when it comes to living to 100.

However, you can increase your chances of living longer in good health through:

  • A healthy lifestyle (not smoking, physical activity and a healthy diet)
  • A positive approach to life, being conscientious and managing stress
  • Building and maintaining social networks 

Reviewed and updated by Emma Juhasz July 2019. Next Review date July 2023.