Science confirms: Humans can't live forever

In the past decade or so, a shift has occurred in science encouraging us to view aging as a disease that can be “cured.” If we can understand all the molecular mechanisms responsible for aging, the thinking goes that we can drastically slow it down.

Studies in mice (and more recently, dogs) have suggested that it may be possible to use certain drugs to extend life by as much as 30%. But there’s no reason to stop there. I often ask scientists in this line of work how old is old enough—how long do we have to live before we decide we are over it?

This line of questioning, it turns out, may be irrelevant. A paper published Wednesday in Nature suggests that humans today already live just about as long as they are ever going to.

The authors analyzed demographic data to conclude that the number of years any one human can live has a natural cap. Even with all of modern medicine’s marvels, they found, people tend to not fare much better than they ever have before. Plus, the age of the world’s oldest person has not increased since the 1990s.

“Our results strongly suggest that the maximum lifespan of humans is fixed and subject to natural constraints,” they wrote.

The oldest person on record was a Frenchwoman named Jeanne Calment, who died in 1997 at 122. For someone to have a stab at reaching 126, the authors calculated, the global population would have to be 10,000 times bigger.

The findings will no doubt inflame the debate over the benefits of anti-aging research. In a separate editorial published in Nature that same day, another researcher asked, “why would anyone think that people could live for much longer than we do now?”

This, of course, belies the real point of most anti-aging research. Sure, there are transhumanist billionaires like Peter Thiel that want to live forever. But most anti-aging researchers are more interested in helping us live more healthily for a longer period of time. As Brian Kennedy, who runs the Buck Institute for Research on Aging, put it to me once: “It’s about healthspan, not just lifespan.”

Discoveries in the field of anti-aging might not help us make it past 100. But they could help us avoid spending the last years of our lives in painful decline.