A new study made headlines last October when it announced that people can only live an average of 115 years. According to the researchers, that was the age at which the brain and the human body just naturally turned itself off. Neither was supposedly made to last longer than that.
Published in the journal Nature, those conclusions sparked a debate in the scientific community on longevity, TIME reports. Some were vindicated due to similar findings, while others would not accept this finiteness to human life, much less a specific number.
As a result, Nature invited other scientists who were vocal critics of the original research to lay out their arguments on the matter. Five separate critiques hashed out the October study, saying that there isn’t necessarily a limit to human age, and that the original authors had made assumptions and overreaching conclusions.
The new studies agree that human life has a limit. But they add that it is premature to put a maximum on it. It is equally possible that humans will continue to live longer, surviving beyond 115 years, they said.
Siegfried Hekimi, professor of genetics at McGill University in Canada, said,
It was reasonable that when everybody lived to 50 that the very long lived, for whatever reason—genetics or luck—would make it to 80.
He added, “If people live on average to 80 or 90, like they do now, then the very long lived make it to 110 or 120. So if the average lifespan keeps expanding, that would mean the long-lived would live even longer, beyond 115 years.”
Trends in longevity have been on the rise, and the average lifespan has gone up since the 1990s. Then, life expectancy among Americans was something like 50 years, while babies born now can be expected to live until 79 years old, on average.
Maximum lifespan per population varies so much annually that results will be skewed if researchers take the wrong snapshot of data, Hekimi said. He and the other critique authors contend that human lifespan stopping at 115 was based on a misinterpretation of data, and nothing more.