A person’s genes play a far greater role in likely lifespan than previously thought, according to a major new study published Thursday in the journal Science.Using data from human twin studies, an international team of researchers arrived at the conclusion that the genetic contribution to how long we’re likely to live is as high as 55%.This new finding is strikingly higher than previous estimates, which have calculated the role of genetics in lifespan could range from 6% to 33%. It’s likely to intrigue — and perhaps disappoint — the fast-growing community of longevity influencers and self-described biohackers touting longer lives through supplements and customized drug regimens.AdvertisementAdvertisementThe study authors said they arrived at this very different figure by separating out what they termed extrinsic mortality (defined as deaths from external factors such as accidents, homicides, environmental hazards and infectious diseases) and intrinsic mortality (deaths caused by internal biological factors such as age-related diseases, genetic mutations and the general decline of health with age).Through treating these two categories of death separately, the researchers said they were able to get a far more accurate estimate of the relationship between genetics and lifespan. It also matches with findings regarding the role of genes in other key physiological traits: Height, body fat distribution and muscle build are all thought to be at least 50% heritable.“The number that we got is not out of nowhere,” said lead study author Ben Shenhar, who researches the physics of aging at the Weizmann Institute of Science in Rehovot, Israel. “If you look at twin studies on pretty much anything in humans, you get this 50%. If you look at the heritability of age of onset at menopause, which is an age-related decline, that is also around 50%.”Morten Scheibye-Knudsen, an associate professor in the department of cellular and molecular medicine at the University of Copenhagen, described th …
