Longevity is in the genes: half of lifespan is heritable
Studies on twins can help to elucidate how much a person’s genes contribute to specific traits such as life span.Credit: Pierre Andrieu/AFP via GettyGenetics has a much larger role in how long a person lives than previously thought, finds a new analysis that challenges decades of scientific consensus.About 55% of the human lifespan is heritable, meaning that more than half of the observed variation in longevity across a population is attributable to genetics. That is a much greater proportion than the previous estimates1,2 of 10–25%, according to the research, which was published today in Science3.The findings should aid in the quest to find specific genes involved in ageing and to develop treatments for ageing and age-related diseases, says study co-author Ben Shenhar, a biophysicist at the Weizmann Institute of Science in Rehovot, Israel.“There is much to be learnt from the genetics of ageing, if we can understand what genes are responsible for healthy ageing,” he says.Shenhar and his colleagues say that previous estimates were much too low because they did not effectively separate deaths caused by extrinsic factors, such as infectious diseases or accidents, from intrinsic ones inside the body, such as the gradual decline of organ function stemming from DNA damage over time.Still working at 107: supercentenarian study probes genetics of extreme longevityTo tease out these factors, the researchers re-examined data, going back to the 1800s, from twin studies in Denmark and Sweden, as well as studies on siblings of centenarians in the United States. Such studies can identify genetic components of traits, Shenhar says, because identical twins share 100% of their DNA, whereas fraternal twins and other sibling pairs share about half on average.
