While enabling us to live longer and healthier lives is one of the main goals of modern medicine, a new study suggests that the maximum lifespan of humans is probably around 150 years.
Gradually diminishing resilience
Biological aging (or senescence), or the speed at which our body degrades, does not necessarily correspond to our chronological age, that is to say the number of birthdays celebrated. Based on this observation, Singaporean researchers have identified a new way of interpreting fluctuations in the number of different types of blood cells, which has enabled the development of a dynamic indicator of the state of the organism (DOSES).
This indicator shows that our body’s resilience slowly declines over the course of our lives, which is part of the reason why it takes longer to recover from illness or injury when we are older. According to the researchers, assuming we can put aside the environmental parameters, diseases and accidents of life, the DOSES provides a reliable method of determining when this resilience stops definitively.
« Extrapolation of this trend suggests that the recovery time and the variance of the DOSI would simultaneously diverge at a critical point of 120-150 years, corresponding to a total loss of resilience. “, Emphasize the researchers.
For this work recently presented in the journal Nature Communications, the researchers studied information on the blood cell counts of more than 500,000 people from databases at UK, to the United States et en Russia, as well as step count data from 4,532 subjects, to measure the rate of decline in individuals’ physical condition.
Significant changes in aging trajectories
Since the number of blood cells could indicate a range of problems in the body, the team used the step count data to ensure that it was a good indicator of overall health and fitness. recovery in general.
The data also made it possible to discover a change in the trajectories of aging from the age of 35, then from the age of 65. This matches some of the limits in place in society, such as the age at which top athletes tend to end their careers, or the age at which we generally retire.
Longer term, the researchers say the study could be used to develop treatments that target diseases without affecting biological resistance, and possibly even one day extend the maximum possible lifespan beyond that. of what it already is. But in any case, it will require more research and data.
“Criticality leading to end of life is an intrinsic biological property of an organism”
The new analysis is broadly consistent with previous studies which mentioned a maximum lifespan of around 120-140 years, although such calculations involve some degree of guesswork and estimation.
Today, the record for human longevity is held by Jeanne Calment, having passed away at the age of 122 years and 164 days. Unless we drastically alter our bodies on a fundamental level, it would be difficult to squeeze too many extra years out of our fragile forms, according to the authors of the new study.
« We conclude that end-of-life criticality is an intrinsic biological property of an organism, which is independent of stressors and constitutes a fundamental or absolute limit to human lifespan. », Conclude the researchers.