A groundbreaking study from the Weizmann Institute of Science, recently published in the journal Science, has upended traditional beliefs about the factors influencing human lifespan. The research indicates that genetics may account for approximately half of the variability in lifespan, a figure that is at least double earlier estimates.
Led by Ben Shenhar under the guidance of Prof. Uri Alon in the Molecular Cell Biology Department, this study challenges the long-held view that non-genetic factors predominantly determine longevity.
"For many years, lifespan was attributed mainly to non-genetic factors, fueling skepticism about genetic determinants of longevity."
Understanding Previous Miscalculations
The research team conducted an analysis of extensive twin databases from Sweden and Denmark, incorporating data from twins raised apart for the first time. This innovative approach allowed the researchers to more accurately distinguish between genetic and environmental influences on lifespan.
Previous estimates were often distorted by what scientists term extrinsic mortality, which includes deaths from accidents, infections, and environmental causes. Older datasets lacked detailed causes of death, making it challenging to differentiate between deaths resulting from biological aging and those influenced by external factors.
To address this issue, the researchers developed a novel analytical method, utilizing mathematical models and simulations of virtual twins. This enabled them to isolate deaths attributed to aging from those caused by outside influences, revealing a much stronger genetic component than had been previously recognized. These findings resonate with observations in other complex human traits and animal studies.
Up to age 80, the heritability of dying from dementia is approximately 70 percent, significantly higher than for conditions like cancer or heart disease.
Transformative Potential for Aging Research
The implications of these findings could revolutionize our understanding of aging and longevity. If genetics indeed plays a more substantial role than previously thought, it enhances the motivation to identify specific genes that affect lifespan.
"For many years, human lifespan was thought to be shaped almost entirely by non-genetic factors, which led to considerable skepticism about the role of genetics in aging and about the feasibility of identifying genetic determinants of longevity," says Shenhar. "In contrast, if heritability is high, as we have shown, this creates an incentive to search for gene variants that extend lifespan, in order to understand the biology of aging and, potentially, to address it therapeutically."
Support for Ongoing Research
Prof. Uri Alon's research is backed by various institutions, including the Sagol Institute for Longevity Research and the Moross Integrated Cancer Center, among others.
