WASHINGTON, Jan 29 (Reuters) – Many factors influence how long you live, such as diet, exercise, smoking, drinking, environment and other variables. It also helps not to get hit by a dump truck. But what about your genes? That has been a contentious question for decades.A new study points to a larger role for genetics than previous research had indicated, estimating the contribution of genes to determining human lifespan at about 50%. That is roughly double what prior research concluded, and it mirrors the findings of lifespan studies in laboratory animals.”Lifespan is undoubtedly shaped by many factors, including lifestyle, genes and, importantly, randomness – take for example genetically identical organisms raised in similar environments that die at different times,” said Ben Shenhar, a doctoral student in physics at the Weizmann Institute of Science in Israel and lead author of the study published on Thursday in the journal Science.AdvertisementAdvertisement”In our work, we tried to give a handle on the amount of variance between different people that can be attributed to genetics. Our study tried to partition the longevity factors into genetics and ‘everything else.’ The ‘everything else’ is around 50% of the pile.”The researchers sought to account for a confounding factor in previous studies that used Swedish and Danish twins, most dating to the 19th century. Those twin studies did not account for deaths caused by violence, accidents, infectious diseases and other factors originating outside the body – called extrinsic mortality – that the authors of the new study said skewed earlier findings about longevity’s genetic component.The cause of death was absent in the historical data, which provided merely the age at death. So if one twin died at age 90 of natural ca …
