Humans have been living longer for decades, and a new study shows there is no ceiling in sight for lifespan.
A study published recently in the Journal of Science found that the death rate of seniors abruptly slows around 80 years old and then plateaus at 105 years old, which they interpreted to mean that humans are not close to a biological limit on how long they can live. The researchers examined records of Italians who had reached 105 years old between 2009 and 2015 (born between 1896 and 1910). Their search resulted in 3,836 people. After verifying their age with their birth certificates, the researchers examined which of those Italians had died during the study period to determine the rate at which different age groups died. This study comes after a 2016 study by scientists at Albert Einstein College of Medicine which put the maximum human lifespan at about 115 years.
The new study focused on mortality rates, which are relatively high in infancy and decrease during a person’s early years. They then go up in a person’s thirties and drastically increase when people reach their seventies and eighties, according to the Centers for Disease Control and Prevention.
However, Elisabetta Barbi, a demographer at the University of Rome, and her team discovered that among very old Italians, the death rate stops rising around age 80, begins to decelerate and then plateaus after age 105. “If there’s a fixed biological limit, we aren’t close to it,” Barbi told The New York Times. Co-author of the study, Kenneth Wachter, a demographer at the University of California, Berkeley echoed Barbi. “The plateau is sinking over time. We’re not approaching any maximum lifespan for humans yet,” he told the Times.
Although the study doesn’t explain why death rates plateau at 105, one possibility is that some people have genes that make them stronger than others, while some have genes that make them more frail. Weaker people will die off sooner, leaving only the more resilient people behind.
Written by: Alexa Lardieri – US News and World Report – June 29, 2018