For years, scientists have debated how genetics and lifestyle influence human longevity. A new Israeli study, published in Science, assigns for the first time a predominant role to genes, upending long-held scientific beliefs.
Genetics Takes Center Stage
55% of human longevity is heritable, versus only 10-25% estimated until now. Environmental factors and lifestyle—whether healthy or unhealthy—therefore lose ground, previously deemed substantial in determining the quality and length of the aging journey. This ratio not only upends scientific dogma, but also raises new questions and challenges about how to act to preserve, steer, and redirect health toward longevity in today’s socio-demographic landscape, which on one hand trends toward aging and on the other toward the adoption of unhealthy behaviors. The research also provides valuable tools and guidance for the development of potential therapies capable of slowing aging processes.
The Study
The researchers started from a distance by analyzing historical data dating back to 1800. Specifically, thousands of twin pairs in Denmark and Sweden were examined, along with relatives of centenarians in the United States, using innovative tools such as a mathematical model able to distinguish between extrinsic mortality—caused by external factors like accidents, homicides, or infectious diseases—and intrinsic mortality, driven by internal aging processes such as organ function decline, DNA damage, cell death, and so on.
The collection of these data was crucial, because once separated and distinguished, it allowed to isolate the true genetic signal, previously “silenced” to some extent by extrinsic mortality—particularly accidental deaths or deaths from infections, highly prevalent in previous centuries—which likely confused the picture or gave a distorted view of the genetics–lifestyle equation in its broad sense.
Scientific Progress
The estimate of genetics’ contribution in earlier studies may have been influenced by the difficulty of clearly identifying deaths not tied to biological aging.
While improvements in public health measures, clinical practice, scientific research, and socio-economic investments in the 20th century reduced extrinsic mortality, they allowed the genetic signal to emerge.
In a Context of Pathology
The study also identified that not all aging-related issues and diseases have the same degree of heritability. For example, dementia and cardiovascular diseases have a high genetic component, while cancer has a much lower heritability, with random cellular mutations or environmental factors playing a larger role.
“Correcting” the Genes
Thus the crucial question of genetic heritability returns. The researchers emphasize that while our DNA is important, genes are not an inevitable “destiny.” Certainly the genetic makeup is immutable, yet it can be corrected to some extent through meaningful lifestyle actions, guiding the remaining 45-50% with proper and healthy behaviors: diet, activity and exercise, socialization and participation in community life, environmental protection.
In conclusion, the information that will emerge from now into the future about understanding which genes are most responsible for healthy aging could enable the development of treatments that slow simultaneously all age-related diseases, in an innovative, revolutionary approach to longevity medicine.
Source
Shenhar B, Pridham D, Lopes de Oliveira T et al. Heritability of intrinsic human lifespan is about 50% when confounding factors are addressed. Science, 2026, Vol. 391, Issue 6784, pp. 504-510. DOI: 10.1126/science.adz1187
Abbonati a Karla Miller
