Biology

Live forever? Scientists say human bodies have no detectable maximum lifespan

There's an old Henny Youngman joke about a doctor who gave a man six months to live, only to find the man couldnt pay his bill, so gave him another six months. That joke more or less summarizes a recent squabble in the academic world concerning the publishing of a new paper, arguing that what we thought we knew about maximum human lifespan may in fact be wrong.

Late last year, a scientific paper published in Nature by researchers at the Albert Einstein College of Medicine argued that the maximum lifespan of humans is fixed, that there is a plateau at 115, and the odds of anybody in the world surviving to 125 in any given year is less than one in 10,000.

Provided your health holds out, living to the grand old age of anywhere between 115 and 125 may sound pretty good, but the study has now been subject to a rebuttal from biologists at Canadas McGill University -- also published in Nature. They argue that there is no evidence for such a limit and that, while one may conceivably exist, its not been found yet.

We examined how old were the oldest people to die, since reliable reports could be obtained until modern times, Dr. Siegfried Hekimi, one of the lead authors of the study, told Digital Trends. In contrast to others who thought they could distinguish a plateau around the age of 115, we showed that no such plateau can be observed. Meaning that as far as anyone can tell the age of the oldest individuals to die might keep going up, just as the average lifespan is going up -- at least in countries like Canada.

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Hekimi points out the way that average lifespans have increased over the years, from 1920 when an average Canadian would live for 60 years, to one born in 1980 who will live 76 years, to one born today who will live 82 years. We haven't reached the plateau yet though.

[Our work] tells us that when living conditions get better -- extraordinarily better -- then both average and maximum lifespan are likely to go up, Hekimi said. What do I mean by extraordinarily good living conditions? Think: enough food, warm shelter in the winter, cool shelter in the summer, vaccination, sewers, fresh uncontaminated food all year round, much lighter workloads.

Ultimately, of course, its going to be average lifespans rather than maximum lifespans that are more significant. Still, if you ever thought you werent going to be able to pay your bills in the 115-125 years allotted by last years Nature study, never fear: things dont have to end there!