The Grapevine

How Long Can We Live? Human Lifespan Not Yet Peaked, Study Says

When we think of growing old, we think of it as a process that brings up closer and closer to death. But this is now being challenged by researchers at the University of California, Berkeley, and the Sapienza University of Rome.

The study titled "The plateau of human mortality: Demography of longevity pioneers" was published in the journal Science on June 29.

The longest verified human lifespan was attributed to Jeanne Calment of France, who passed away in 1997 at the age of 122 years. But could our upper limit be something higher than that?

Over 3,800 Italians born between 1896 and 1910 were recruited to have their data examined. This meant they were supercentenarians (lived to the age of 110) or at least, semi-supercentenarians (lived to the age of 105) during the period of study. 

The study revealed that the likelihood of dying at the age of 68 was around 2 percent, at the age of 76 was around 4 percent, and at age 97 was close to 30 percent. What the researchers suggest is that the risk of death peaks at 60 percent when a person hits the age of 105 and actually holds steady after that.

"Our data tell us that there is no fixed limit to the human lifespan yet in sight," said study senior author Kenneth Wachter, a professor emeritus of demography and statistics from Berkeley. "Not only do we see mortality rates that stop getting worse with age, we see them getting slightly better over time."

Simply put, once you cross the age of 105, whether you survive the next year or not is like tossing a coin, he said. But as exciting as it may sound to us, not all experts are in agreement with the hypothesis. 

It makes sense that the doubling could not go on forever according to Brandon Milholland, an aging researcher at Albert Einstein College of Medicine.

"If mortality is at 60 percent, it cannot eventually double to 120 percent — that is mathematically impossible," he said. But the paper "models late-life mortality as suddenly stopping in its tracks and remaining completely flat," which he found to be "highly implausible."

The findings could not provide a strong explanation as the study was "purely statistical and demographic in nature," according to Gizmodo. The data used in this particular study was limited as it involved Italians exclusively.

Furthermore, all studies examining people of extreme old age face a paucity problem since so few people live past the age of 105. Those who cross that number seem to do so because of natural selection. Many researchers suggest that longevity is largely a matter of genetics, even more so than lifestyle.

Previously, a study published in 2016 by the Albert Einstein College of Medicine argued that the maximum human lifespan had already been reached. The average maximum human lifespan was 115, the researchers stated, adding that 125 years may be the absolute limit of the human lifespan.