- A new study suggests once people reach 105 years old, their chances of dying every day are about 50-50.
- This means the risk surges as we age, but it essentially levels off if we reach 105.
- It adds to the debate between two groups of scientists about whether humans have reached their upper age limit or not.
The oldest person ever was the French woman Jeanne Calment who died at the age of 122 years, 164 days in 1997 – a record she’s held for 21 years.
As nobody has outlived her age since then, it could be assumed that humans have reached their limit. But according to a new study, published in the journal Science, this may not be true.
Researchers from the University of California, Berkeley and Sapienza University in Rome tracked the lives and deaths of nearly 4,000 Italian people aged 105 and older between 2009 and 2015. They found that the odds of dying after reaching 105 essentially plateaued.
It becomes more likely we are going to die with every day we are alive, because death rates rise exponentially as we age. However, if we get through our 80s, the chances of dying decelerate, and by age 105, our chances of dying every day are about 50-50.
“It’s the equivalent of tossing a coin each year,” Jim Vaupel, one of the authors who is a specialist in ageing at the Max Planck Institute for Demographic Research in Germany, told The Guardian.
The results showed people between 105 and 109, also known as semi-supercentenarians, had an expected further lifespan of one and a half years. That life expectancy was the same for the 110-year-olds, also called supercentenarians, which is why there is a plateau.
“Our data tell us that there is no fixed limit to the human lifespan yet in sight,” said Kenneth Wachter, a UC Berkeley professor emeritus of demography and statistics and senior author of the study, in a statement. “Not only do we see mortality rates that stop getting worse with age, we see them getting slightly better over time.”
There is a fierce debate in the scientific community about whether humans have reached their upper lifespan limit or not. Vaupel and Wachter believe their paper is evidence that we may not have.
Mortality rates surge as we approach our 80s and 90s because of degenerative diseases like dementia, and higher risk of stroke, cancer, and pneumonia.
But Wachter and Vaupel pose a theory in their paper – that people who survive these ailments do so because of natural selection. The more frail people die earlier, while more robust people can reach supercentenarian ages. According to Wachter, a similar lifestyle pattern is seen in flies and worms.
“What do we have in common with flies and worms?” he said. “One thing at least: We are all products of evolution.”
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