‘We are living longer, but only because fewer of us die when we are children’

Don’t be fooled by rising average lifespans – a study concluded biology in old age is the same as ever but fewer of us are dying as children, writes Miriam Stoppard

Living for ever or turning back the clock are long-held fantasies, with countless products and ­procedures playing to fears, ­promising to give us extra years.

But despite all our dreams of longevity, it is unlikely we can slow the rate we age.

That is the conclusion of an ­unprecedented study of lifespan stats in human and non-human primates.

It aimed to test the rule that we have a relatively fixed rate of ageing from adulthood onward.

An international collaboration of scientists from 14 countries, including José Aburto from Oxford’s Leverhulme Centre for Demographic Science, analysed birth and death data ­spanning centuries and continents.

And we are living longer – but that’s to do with more and more of us surviving into adulthood.

Aburto says: “Our findings support the theory that, rather than slowing down death, more people are living much longer due to a reduction in mortality at younger ages.

“We compared birth and death data from humans and non-human primates and found this general pattern of mortality was the same in all of them. This suggests that ­biological, rather than environmental factors, ultimately control longevity.

“The statistics confirmed that individuals live longer as health and living conditions improve, which leads to increasing longevity across a population. Nevertheless, a steep rise in death rates, as years advance into old age, is clear to see in all species.”

The research team analysed ­information from 30 primate species, 17 in the wild and 13 in zoos, including gorillas, baboons and chimpanzees. It examined birth and death records from nine diverse human populations in 17th to 20th-century Europe, the Caribbean and Ukraine, and two hunter gatherer groups between 1900 and 2000.

All the data revealed the same general pattern of mortality: a high risk of death in infancy that rapidly declines in the teenage years, remains low until early adulthood, and then continuously rises with advancing age.

Aburto adds: “Our ­findings confirm that, in historical populations, life expectancy was low because many people
died young.

“But as medical, environmental and social improvements continued, life expectancy increased.

“More and more people get to live much longer now. However, the ­trajectory towards death in old age has not changed.

“This study suggests evolutionally biology trumps everything and, so far, medical advances have been unable to beat these biological constraints.”