The dominant idea is that humans genetically are inclined to live 120 years and no longer. But a new study published in Science demonstrates that that’s not necessarily so – that once a body reaches 105 years old, there’s not really any further damage from aging – just the same old wear and tear you’ve gotten all along:
The odds of dying stop rising in people who are very old, according to a new study that also suggests we haven’t yet hit the limit of human longevity.
The work shows “a very plausible pattern with very good data,” says demographer Joop de Beer of the Netherlands Interdisciplinary Demographic Institute in The Hague, who wasn’t connected to the research. But biodemographer Leonid Gavrilov of the University of Chicago in Illinois says he has doubts about the quality of the data.
As we get older, our risk of dying soars. At age 50, for example, your risk of kicking the bucket within the next year is more than three times higher than when you’re 30. As we head into our 60s and 70s, our chances of dying double about every 8 years. And if you’re lucky enough to hit 100 years, your odds of making it to your next birthday are only about 60%.
But there may be a respite, according to research on lab animals such as fruit flies and nematodes. Many of these organisms show so-called mortality plateaus, in which their chances of death no longer go up after a certain age.
So, in the new study, demographer Elisabetta Barbi of the Sapienza University of Rome and colleagues turned to a database compiled by the Italian National Institute of Statistics. It includes every person in the country who was at least 105 years old between the years 2009 and 2015—a total of 3836 people. Because Italian municipalities keep careful records on their residents, researchers at the institute could verify the individuals’ ages. “These are the cleanest data yet,” says study co-author Kenneth Wachter, a demographer and statistician at the University of California, Berkeley.
The risk of dying leveled off in people 105 and older, the team reports online today in Science. That means a 106-year-old has the same probability of living to 107 as a 111-year-old does of living to 112. Furthermore, when the researchers broke down the data by the subjects’ year of birth, they noticed that over time, more people appear to be reaching age 105.
“[That’s] strong evidence that if there is a maximum limit to human lifespan, we are not close to it yet,” Wachter says.
The original study (with all the lovely data) is available here.