Ben Shenhar and Uri Alon Find Genes Explain 55% Of Lifespan

Ben Shenhar and Uri Alon published a study in the journal Science reporting that intrinsic genetic factors account for about 55% of variation in human lifespan after the authors adjusted for extrinsic mortality.

The researchers separated extrinsic mortality — deaths from accidents, homicides, environmental hazards and infectious disease — from intrinsic biological aging and calibrated a mathematical model using historical twin datasets from Denmark and Sweden to isolate genetic effects.

Ben Shenhar, lead study author and researcher at the Weizmann Institute of Science in Rehovot, said in published remarks that the 55% figure aligns with heritability seen in other physiological traits, while Eric Verdin, president and CEO of the Buck Institute for Research on Aging, cautioned in an interview that classifying infection-related deaths as extrinsic could inflate the genetic estimate.

Previous heritability estimates for human lifespan ranged from 6% to 33% in past studies and about 25% from a famous Danish twin study, a disparity the authors attribute to failure to account for extrinsic mortality in earlier analyses.

The authors called for deeper searches for longevity genes and sequencing of centenarian genomes to identify interacting variants, and outside researchers said methodological replication and alternate classifications of intrinsic versus extrinsic deaths are needed to confirm the 55% finding.