New Study Finds Genetics Plays Bigger Role in Lifespan
How long people live has always been linked to lifestyle choices, medical care, and chance. However, new research now suggests that genetic factors in human lifespan play a much larger role than earlier studies suggested.
Scientists from the Weizmann Institute of Science in Israel report that genetics may explain about half of the differences in human lifespan. This estimate is significantly higher than past findings, which often placed the genetic contribution much lower.
The study was published in the journal Science and may change how researchers approach ageing and longevity.
Why Earlier Studies May Have Missed the Full Picture
Previous research on lifespan has relied heavily on twin studies from countries such as Sweden and Denmark. Many of these studies began as far back as the 19th century.
However, those early datasets did not properly account for deaths caused by accidents, violence, or infectious diseases. Scientists refer to these as extrinsic causes of death. These events are largely unrelated to a person’s biology but strongly affect when someone dies.
As a result, earlier estimates underestimated the role of genetic factors in human lifespan.
A New Way to Separate Genetics From External Causes
The researchers applied a new mathematical approach to adjust for extrinsic mortality. By removing deaths caused by external events, they could focus more clearly on deaths linked to ageing and disease.
Once they made this correction, the genetic influence became much clearer. The findings showed that genetics accounts for roughly 50 per cent of lifespan variation, while the remaining share comes from environment, lifestyle, and random events.
Importantly, the study confirmed that chance still plays a major role, even among people with similar genes and environments.
What Twin Studies Revealed After the Adjustment
To validate their method, the scientists examined more recent Swedish data. This included identical twins raised together, identical twins raised apart, and fraternal twins.
Identical twins share the same genes. When they grow up in different environments yet show similar lifespan patterns, it strengthens the case for genetics. Fraternal twins, who share only about half their genes, helped researchers further separate genetic effects from environmental influences.
As deaths from infections and accidents declined over time, the heritability of lifespan increased, reinforcing the role of genetics.
Why Lifespan Is Different From Other Health Traits
Traditional twin study methods work well for traits such as height or blood pressure. Lifespan, however, behaves differently.
Average lifespan is highly sensitive to external threats. When researchers fail to adjust for those threats, genetic signals become hidden. This explains why lifespan genetics appeared weaker in earlier studies.
Once corrected, genetic factors in human lifespan emerged as a major influence.
Protective Genes and the Mystery of Healthy Ageing
The study also highlights that genes can affect lifespan in both harmful and protective ways.
Some genetic variations increase the risk of serious diseases. Others appear to protect people from age-related illnesses. This may explain why many centenarians reach old age without major health problems.
Researchers believe longevity does not depend on one or two genes. Instead, hundreds or even thousands of genes likely work together to influence how the body ages.
What This Means for Future Ageing Research
Low genetic estimates in the past may have discouraged investment in ageing research. This new evidence suggests those concerns were misplaced.
By showing that genetic factors in human lifespan are stronger than once thought, the study supports renewed efforts to identify genes that promote healthy ageing.
Such research could eventually lead to better prevention strategies, earlier risk detection, and improved quality of life as people grow older.
Conclusion
Genes matter more than previously believed when it comes to how long people live. Still, they do not act alone.
Lifestyle choices, healthcare access, and random life events remain important. Genetics loads the gun, but environment and chance often pull the trigger.
Understanding this balance may help society move toward healthier ageing for future generations.
Source: Inputs from various media Sources
I’m a pharmacist with a strong background in health sciences. I hold a BSc from Delhi University and a pharmacy degree from PDM University. I write articles and daily health news while interviewing doctors to bring you the latest insights. In my free time, you’ll find me at the gym or lost in a sci-fi novel.
- Health News and Updates,People Forum
- 1 February 2026
- 11:00
