An international team led by Joris Delan of Leiden University has published a study suggesting that about 50% of human lifespan may be linked to genetics. Until now, the role of heredity was thought to be limited to just 6–25%.
For the analysis, the researchers used a new mathematical model and extensive twin data from Sweden, Denmark, and the United States to separate genetic factors from external ones. The data were analyzed by decade of birth to account for the way mortality from infections has declined over time. This made it clear why genetic influence had previously seemed small: in the past, people were more likely to die from external causes unrelated to heredity.
The scientists stress that although genes do play an important role, this does not diminish the importance of lifestyle, medicine, and the environment. Heritability is a predisposition, not a sentence. Understanding the genetic mechanisms of aging will help create personalized medical strategies aimed at preventing age-related diseases and extending healthy life.
