Long lifespan more related to genetics than thought, new study claims

Until now, studies have suggested only around 10 per cent to 30 per cent of a lifespan can be put down to genetics, with illnesses, accidents and lifestyle factors such as eating well, not smoking and exercising making up the rest.

However, a new study published in the journal Science has discovered the role genes play in the human lifespan is actually more like 55 per cent..

Experts looked at twin studies and found that when deaths from external factors, such as accidents or infectious disease, were lower, the role of genes appeared to increase.

Historically, some past studies have also relied on hundreds of years' worth of potentially poor-quality data and included deaths when things such as disease and poor healthcare were far more common.

Daniela Bakula and Morten Scheibye-Knudsen, assistant professors at the Department of Cellular and Molecular Medicine, University of Copenhagen, wrote in an accompanying editorial that the findings "carry important implications".

They said: "If lifespan is largely fixed by genetics, then the scope for influencing the rate of ageing is limited, particularly for lifestyle interventions.

"Conversely, if genetic contributions are minimal, efforts to understand ageing through genetic approaches are difficult to justify.

"Clarifying the role of inherited variation in ageing-related mortality is therefore central to both biological understanding and societal expectations."

They said the new work strengthens the argument for looking at which genetic variants are associated with a long life and which genetic differences affect biological pathways that regulate ageing.

They said the work also agrees "with the observed 50 per cent heritability of other complex traits".

"Perhaps this means that intrinsic rates of ageing are tightly optimised through evolution, in line with other traits such as cognitive function and metabolism."