Genetics Play Key Role in Human Lifespan, Doubling Previous Estimates, New Study Reveals
January 29, 2026
Funding and affiliations include support from multiple Weizmann institutes and foundations, with key figures holding prominent longevity-related chairs.
The model used Denmark and Sweden twin data to calibrate how extrinsic mortality interacts with intrinsic aging.
A new study published in Science argues that genetics accounts for more than half of the variation in human lifespan, nearly double previous estimates, though lifestyle and environment still play a significant role.
Healthy behaviors like regular exercise, a balanced diet, and strong social connections can modestly extend lifespan within a person’s genetic limits, but they cannot override an unfavorable genetic ceiling.
The findings align the heritability of lifespan with other complex traits and suggest genetic determinants of longevity are substantial, potentially guiding future gene-variant searches and therapeutic aging research.
The researchers developed a framework that uses virtual twins to separate deaths from biological aging and external causes, addressing gaps in historic datasets lacking cause-of-death information.
Expert reactions from independent scientists, including those at the University of Adelaide, call the study thorough and a meaningful extension of aging research from animals to humans.
The study analyzed twin data to separate extrinsic mortality (accidents, environment, infections) from intrinsic mortality (internal aging factors) to isolate genetic influence on aging.
A mathematical model adjusted for extrinsic mortality was validated with recent Swedish data, showing heritability increases as extrinsic mortality decreases.
Experts emphasize that longevity is polygenic and complex, involving many genes rather than a single gene, with practical clinical applications decades away.
Implications point toward identifying specific longevity genes and mechanisms governing internal clocks, potentially guiding therapies to slow aging and age-related diseases.
Researchers highlight that substantial genetic influence supports large-scale efforts to map longevity-associated variants, refine polygenic risk scores, and guide drug discovery in aging pathways.
Summary based on 11 sources
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Sources

The Guardian • Jan 29, 2026
The secret to long life? It could be in the genes after all, say scientists
CNN • Jan 29, 2026
How do you live longer? Your genes may help
Yahoo News • Jan 29, 2026
Study finds greater role for genetics in driving human lifespan
NBC News • Jan 29, 2026
Longevity: A person's genes play a much larger role in lifespan than thought