People are twice as likely to inherit their lifespan as previously thought, new research suggests.
The genetic contribution to how long a person lives is around 50 per cent, based on health databases in Denmark and Sweden. This reflects heritability, the share of lifespan differences due to genes.
For decades, many scientists believed genes and ancestry accounted for between about 10 and 25 per cent of longevity.
The research was led by scientists at the Weizmann Institute in Israel, with the Karolinska Institute in Sweden and Leiden University.
The earlier underestimates arose from limited historic health and mortality data, where deaths due to war, infectious disease, risky or unsafe work, accidents, poor diet and lack of medical care were hard to separate in records.
“For many years, human lifespan was thought to be shaped almost entirely by non-genetic factors, which led to considerable scepticism about the role of genetics in ageing and about the feasibility of identifying genetic determinants of longevity,” said Ben Shenhar of the Weizmann Institute.
Environmental forces such as disease or living conditions can mask or confound potential genetic effects.
Hereditary causes of death, for those not killed first by external causes, mean “processes originating within the body, including genetic mutations, age-related diseases and the decline of physiological function with age.” the researchers said.
“If heritability is high, as we have shown, this creates an incentive to search for gene variants that extend lifespan, in order to understand the biology of ageing and, potentially, to address it therapeutically.” said Shenhar.
Other recent research has pointed to a potential role for taurine, an amino acid, in slowing the ageing process.
Scientists have also highlighted the bowhead whale’s 200-year lifespan, attributed to a cellular protein that may protect against carcinogenic mutations.