Science

Aging: what is the maximum age that a human being can reach?

A race lost in advance? Eat a balanced diet, be physically active, take food supplements and become your doctor’s best friend… Reflexes which can improve our quality of life, but which will not be able to lengthen our duration on Earth much. Here is the conclusion of a Russian study, published on May 25, 2021 in the journal Nature Communications, that the aging process is inevitable with the current state of medicine. “Aging leads to an exponential acceleration in the risk of dying: from the age of 40, the probability of falling ill and dying doubles every eight years! That’s what aging is ”, notes with pessimism Peter Fedichev, director of the laboratory for Simulation of biological systems at the Institute of Physics and Technology in Moscow (Russia) and author of the study.

Thanks to a model that simulates aging, this researcher and his team have shown that the bodily deterioration linked to this process inexorably leads to a point of no return somewhere after the age of 120: “This seems to be the limit and it is due to a loss of resilience, that is, of the body’s ability to deal with stress. When you’re young and healthy it’s very easy to deal with them, but as you get older the same level of stress will require more and more effort to get back into balance, even for healthy people. . ”

A model to estimate the trajectory of aging

The model used was designed using information from the UK Biobank, a British database that brings together health data from over 500,000 people. “This information was used to predict a person’s likelihood of dying based on health variables, such as the amount of blood cells., he explains. But this information, very complete on the state of health of each person, did not allow to see the trajectory of each person’s health, because it only showed an image at a given moment. However, we needed to study the way in which these variables changed over time. ”

To do this, they completed the model with physical activity data (number of steps taken per day), collected on 4,815 users over approximately five years, with an application developed by Gero.ai, a company run by Peter Fedichev. “Biological clocks, such as DNA methylation or le number of blood cells, evolve in the same way, so by looking at the physical activity one can get an idea of ​​all these biological subsystems ”, details Tim Pyrkov, researcher at Gero.ai and co-author of the study. These trajectories were confirmed by regular blood tests on 1,082 users over three years.

A trajectory towards disaster

Thanks to this model, the researchers showed that the aging process resembles what can be observed when other complex systems approach cataclysm, such as ecological systems or financial markets. These complex systems are made up of several sub-systems, which evolve independently when the system is doing well, but which begin to correlate when things are bad. When, literally, nothing is right. “We are always faced with the stresses of life, so the different physiological parameters vary all the time, like a wave passing over and then under the balance line continuously. After the age of 40, we see three warning signs: these fluctuations are greater and greater; the time required to bring a parameter back to the equilibrium point is increasingly long; and these different parameters, which normally evolve independently, start to oscillate together: when one goes badly, the others tend to go bad too, and it becomes more difficult to bring them back to balance, sums up Peter Fedichev. As with other complex systems, with aging the problems do not come alone. ”

By extrapolating these aging trajectories, they came to the conclusion that after 100 years of existence, the time required to bring the organism back to equilibrium becomes almost infinite, as the rate of recovery (or the resilience of the body) disappears entirely. “Injuries take longer and longer to heal, and if you’re lucky enough to hit 110, it’ll only take a little illness to kill you, because the treatments that helped your body recover when you turned 70 are no longer. quite effective. ”

If we improve our resilience, could we become immortal?

According to the authors, this downward trajectory to the grave is inevitable, at least with current treatments. “Today, we are focusing on reducing the risk, controlling cholesterol, trying to keep our health parameters in the normal way. But these interventions against the risk can do nothing against this loss of resilience sufferede by the body, so they are doomed to lose the “war”. Its allow ushave perhaps to improve our quality of life in old age, but we will not be able to go beyond 120 years ”, he concludes.

Maybe we’ll just have to live well until the age of 120 (that’s not bad, after all). But researchers are convinced that there is a solution to postpone this fateful date: treatments that would increase this resilience. “New approaches, like genius genetics perhaps, could improve our ability to bring these physiological parameters back to balance, allowing to control their fluctuations even when they become more and more important. With treatment like this (yet to be found), current medicine might be enough to keep us alive indefinitely! ” he dreams out loud. But for the moment, 120 years is already good – remember that Jeanne Calment, dean of humanity, would have died around that age, at 122!

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