The death of the world’s oldest person, Maria Branyas Morera, at the age of 117 might cause many to ponder the secrets of an exceptionally long life, but scientists say it could be best to avoid taking advice on longevity from centenarians themselves.
According to the Guinness World Records website, Branyas believed her longevity stemmed from “order, tranquility, good connection with family and friends, contact with nature, emotional stability, no worries, no regrets, lots of positivity and staying away from toxic people”.
However, Richard Faragher, a professor of biogerontology at the University of Brighton, said that in reality scientists were still trying to work out why some people lived beyond the age of 100.
Faragher said there were two main theories and they were not mutually exclusive.
The first, he said, was that some individuals were essentially just lucky. In other words, just because centenarians had certain habits, it did not mean those habits were driving their longevity – an error in logic known as “survivorship bias”.
“Merely because you have survived smoking 60 a day doesn’t mean that smoking 60 a day is good for you,” Faragher said.
The second theory, he said, was that centenarians had specific genetic features that equipped them to live a longer life – in other words they were rendered more robust as a result of their genetics.
Faragher said both theories, however, resulted in the same warning: “Never, ever take health and lifestyle tips from a centenarian.”
He added: “What you see with most centenarians most of the time – and these are generalisations – is that they don’t take much exercise. Quite often, their diets are rather unhealthy,” noting that some centenarians were also smokers.
“This flies in the face of a lot of epidemiological evidence we have on how to extend your healthy life expectancy,” he said, adding that one large study found that not smoking, taking exercise, drinking in moderation and eating five servings of fruit and vegetables a day could increase life expectancy by up to 14 years.
“The fact that [centenarians] do many of these unhealthy things and still just coast through [life] says they’re either lucky or typically very well endowed [genetically],” he said.
Branyas acknowledged luck had played a role in her long life, while her daughter Rosa Moret once attributed it to genetics. “She has never gone to the hospital, she has never broken any bones, she is fine, she has no pain,” Moret told regional Catalan television in 2023.
Faragher added that many of the mooted possibilities for why centenarians live longer could actually be examples of reverse causation. For example, the idea that having a positive mental outlook can help you live for a very long time might, at least in part, be rooted in people being more sanguine because they have better health.
“When was the last time you had a really positive mental attitude and toothache?” he said.
Faragher added one problem was that when considering centenarians, there was a tendency to focus on things that might have aided their survival. “But we don’t consider the dis-enablers,” he said.
Prof David Gems, a geneticist at University College London, said that while sex was an important factor in longevity – with women ageing more slowly than men – he agreed luck was important, noting that one example was the natural variability in ageing rate.
“I work on nematode worms which live for only a couple of weeks,” he said. “The worms are genetically identical to one another, and they are kept under identical conditions, but the first worms die of old age at around 10 days, and the last at around 30 days.”
But while at an individual level a dose of luck could help explain why some people live beyond 100, experts say there are well-known factors that can help to improve life expectancy at a population level, including improvements in healthcare and hygiene.
“From about 100 years ago, what we started seeing was huge advances in life expectancy driven by improvements in reducing the likelihood that children die,” said David Sinclair, the chief executive of the International Longevity Centre, noting that was largely down to the introduction of vaccinations and clean water.
“What we’ve had over the last 20 years, and we’re going to see over the next 20 years, is a similar focus in terms of old age,” Sinclair said, adding that included improvements in vaccines for flu and shingles, statins, and other medications that would help increase life expectancy among older people.
But he said governments also needed to take action to help individuals to make healthier choices – choices that would ultimately help them live longer – adding that many people lived in environments where it was difficult to exercise, eat well or avoid pollution.
Even if a person lives into triple figures, however, it is not necessarily the case that life will be filled with balloons and blazing birthday cakes.
As Sinclair said, while news stories about centenarians tended to be upbeat, it often emerged that such individuals faced challenges, such as living alone for many years.
“The reality is not always as positive as it seems,” he said.
