Science now believes that our biological expiration date is more hereditary than we thought.

For years, the scientific consensus and popular culture have repeated a reassuring mantra: genes they only determine 20 or 25% of life expectancy. The rest of this fell on our shoulders directly with the lifestyle, diet or even the environment we surround ourselves with. But this figure, which corresponded to old studieshas changed radically.

The study. A study published this week in Science has come to shake the foundations of biogerontology. Led by molecular biologist Uri Alon of the Weizmann Institute in Israel, the research suggests that We have been massively underestimating the role of DNA. Something that they have been able to know after cleaning the data from the statistical “noise” with a very resounding conclusion behind it: the heritability of human life expectancy is around 55%.

What we knew. The percentage of participation of current genetics was based on research carried out in the 90s and whose key was the definition of “dying.” The oldest studies analyzed cohorts of Danish-Swedish twins taking mortality as a whole.

In this way, if one twin died of cancer at 90 and the other from a car accident at 30, the statistics interpreted that genetics had very little influence.

The present. But now, Alon’s team has applied a new mathematical model to separate two concepts that used to be mixed up. One of these was extrinsic mortality, that is, deaths caused by external and random factors such as accidents, pandemics or wars.

On the other hand, we have intrinsic mortality, which is true biological aging and is not due to an accident, but to the ‘wear and tear’ of the organism over time. In this way, by removing the noise of extrinsic mortality from historical data, the weight of genetics begins to skyrocket.

The results. The new study, published at the end of January, is not just based on a simulation but has analyzed decades of records. On the one hand, data from twins born between 1870 and 1900 have been reanalyzed, which are the original studies where the extrinsic factor was included. By removing it, the genetic correlation again became much stronger.

The team crossed their models with sibling data for 444 American centenarians confirming that extreme longevity clusters in families much more than chance or shared environment could explain. In this way, the study corrects what experts call prior estimation biases. That is, the 20-25% figures were not wrong. per sebut they included too much “bad luck.”

Lifestyle matters. That the weight of genetics is much greater than we think, does not mean that we should abandon the gym and a balanced diet. And although genetics determine 55% of aging, the other almost half continues to depend on the environment and lifestyle. And this must continue to be maintained.

On the other hand, this has enormous implications for personalized medicine. If the “expiration date” of our tissues is more programmed than we thought, anti-aging therapies will have to focus much more on editing or modulating that genetic load, and not just on telling us to eat more vegetables (which too).

Images | LOGAN WEAVER | @LGNWVR

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