“Who wants to live forever?”, sang the legendary Freddie Mercury. A question that's making quite a bit of sense, especially in the tech industry. In Silicon Valley, extending human life to the point of immortality has become a goal to pursue. Many big names in Big Tech companies have invested funds in initiatives to solve the problem of death, as if it were just an update of the operating system.
What if death simply couldn't be undone? If longevity has a limit, what do we do? Researchers have addressed the question of how long we can live if, by a combination of serendipity and genetics, we don't die of cancer, heart disease or accidents. And in a studio published yesterday in Nature Communications they say that sheltered from these events, our progressive decline limits the maximum life span for humans between 120 and 150 years.
Whatever happens, does human life have a deadline?
For the study, Timothy Pyrkov and fellow researchers at a Singapore-based company called Gero looked at three large cohorts in the United States, the United Kingdom and Russia. In order to assess deviations from "perfect health," they looked at factors including changes in blood cell counts and the daily number of steps taken, and analyzed them by age group.
For each of these factors the pattern is the same: increasing age has resulted in a predictable and progressive decline in the body's ability to return parameters to a stable level after an interruption. When Pyrkov and his colleagues in Moscow and Buffalo, NY, used this rate of decline to determine when resilience would disappear entirely, leading to death, they found a range of 120 to 150 years.
Several variables joined by a constant
Measurements such as blood pressure and blood cell counts have known ranges, the team points out, while step counts are highly variable and personal. The fact that Pyrkov and colleagues chose a variable so different from blood counts and still found the same decline over time may suggest a real factor in the pace of aging at play in several domains.
The co-author of the study Peter Fedechev, who trained as a physicist and co-founded Gero, says that although most biologists consider blood cell counts and step counts to be “quite different,” the fact that both sources “picture exactly same future” suggests that this “constant” of the pace of aging is real.
What social factors do the results reflect?
“We observed a steep turn at about age 35-40 that was quite surprising,” Pyrkov says. For example, he notes, this period is often when an athlete's athletic career ends, “an indication that something physiological may actually be changing at this age.”
The desire to unlock the secrets of immortality has probably existed as long as humans have been aware of death. But a long human lifespan does not necessarily indicate long health. The goal shouldn't be so much to live longer, but to live healthier for longer.
Death isn't the only thing that matters. Other things, such as quality of life, begin to matter more and more as people suffer the loss of it. The death modeled in this study is only the last act. The question is: can we extend life without also extending the proportion of time that people experience a frail state?
The researchers' final conclusion is interesting to see. According to the study, treating diseases in the long term will ultimately not have the desired effect. The fundamental biological processes of human life aging will continue.
Then at least let's slow it down
The idea of slowing the aging process has attracted attention. Not only in Silicon Valley among those who dream of upload their memories to computers, but also in a group of researchers. Scientists who see such interventions as a means to "compress morbidity", to reduce disease and infirmity and prolong, if not the length of human life, at least that of health.
Whether this will impact the "fundamental maximum limits" identified in this study on Nature Communications. remains highly speculative. But some studies are being launched (for example the very interesting ones on the metformin) with the aim of attenuating the characteristic indicators of aging.
In this same vein, Fedichev and his team are not discouraged by their estimates of the maximum human lifespan. Their view is that their research marks the beginning of a longer journey. “Measuring something is the first step before producing a change,” says Fedichev.
And the point is precisely this: given our nature, to take away this "expiration date" we must work to change ourselves, to increase our abilities: password H+.
