The Genetic Impact on Lifespan: New Findings
While the threat of accidents or injuries is always present, it turns out that our genes might play an even bigger role in determining how long we live than we previously thought. A recent study analyzing twin data from the Weizmann Institute of Science in Israel suggests that genetics could account for around 55 percent of the variability in human lifespans.
This figure is significantly higher than earlier estimates, which ranged from about 20 to 25 percent, with some studies suggesting it could be as low as 6 percent. This new understanding could reshape how we view genetic aging and the search for genes linked to longevity.
“For a long time, people believed that human lifespans were mostly influenced by non-genetic factors,” said molecular biologist Ben Shenhar from the Weizmann Institute. This skepticism made it tough to see the potential role genetics might play in aging and identifying genes that contribute to longevity.
Deaths can fall into two categories: intrinsic and extrinsic. Intrinsic factors include genetic and internal aging processes, whereas extrinsic causes are those like accidents and infections. Determining how each factor contributes to mortality hasn’t always been clear due to insufficiently detailed historical data.
The researchers meticulously examined data from thousands of twins, including siblings raised apart—data that hadn’t been fully utilized in previous studies on lifespan heritability. This twin information is vital as it helps to separate genetic influences from lifestyle factors acquired after birth.
By using sophisticated mathematical models to separate out extrinsic mortality, they found that intrinsic factors become more pronounced as people age. Interestingly, their new estimate of genetic influence aligns more closely with how genes affect other physical traits, like height.
“This high level of heritability is in line with other complex human traits and lifespan heritability seen in other species,” the researchers note in their published work. While this new research doesn’t directly contradict previous findings, it does suggest that past data may not have fully captured the nuances of life and death dynamics.
The next step for the researchers is to validate these findings against more contemporary datasets that better isolate various causes of death. Understanding the significant role genetics plays in lifespan brings up many questions about which specific genes are most influential and how they operate—this could open doors to future research.
“If we have shown high heritability, it motivates us to look for gene variants that could extend lifespan to better understand aging biology and possibly find therapeutic solutions,” says Shenhar. This research has been recorded in a recent edition of Science.
