University of Washington
The number of people living beyond the age of 100 has been increasing for decades, up to almost half a million people worldwide.
However, there are far fewer "supercentenarians ," people who live to be 110 or even older. The oldest living person, Jeanne Calment of France, was 122 years old when she died in 1997; Currently, the oldest person in the world is Kane Tanaka, 118, of Japan.
Such extreme longevity, according to new research from the University of Washington, will likely continue to slowly increase by the end of this century, with estimates showing that a lifespan of 125 years, or even 130 years, is possible.
"People are fascinated by the extremes of humanity, whether it’s going to the moon, how fast someone can run in the Olympics or even how long someone can live," said lead author Michael Pearce, a doctoral student in statistics. from the University of Washington. "With this work, we quantify the probability that we believe any individual will reach various extreme ages this century."
Longevity has ramifications for government and economic policies, as well as for people’s own health and lifestyle decisions, making what is likely, or even possible, relevant at all levels of society.
The new study, published in Demographic Research , uses statistical models to examine the extremes of human lifespan. With ongoing research into aging, the prospects for future medical and scientific discoveries, and the relatively small number of people who have verifiably reached age 110 or older, experts have debated the possible limits of what is known as maximum age reported at death. While some scientists argue that disease and basic cellular deterioration lead to a natural limit on human lifespan, others maintain that there is no limit, as evidenced by record-breaking supercentenarians.
Pearce and Adrian Raftery, a professor of sociology and statistics at the University of Washington, took a different approach. They asked what the longest human life expectancy could be anywhere in the world by the year 2100. Using Bayesian statistics, a common tool in modern statistics, the researchers estimated that the 122-year world record will almost certainly be broken, with a strong probability of at least one person living to be between 125 and 132 years old.
To calculate the probability of living beyond the age of 110 , and to what age, Raftery and Pearce turned to the most recent version of the International Longevity Database, created by the Max Planck Institute for Demographic Research. That database tracks supercentenarians from 10 European countries, as well as Canada, Japan and the United States.
Using a Bayesian approach to estimate probability, the University of Washington team created projections for the maximum reported age at death in the 13 countries from 2020 to 2100.
Among their findings:
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As it is, supercentenarians are outliers, and the probability of breaking the current age record increases only if the number of supercentenarians increases significantly. With an ever-expanding world population, that’s not impossible, researchers say.
People who achieve extreme longevity are still rare enough to represent a select population, Raftery said. Even with population growth and advances in health care, there is a flattening of the death rate after a certain age. In other words, someone who lives to age 110 has about the same chance of living one year longer as, say, someone who lives to age 114, which is about half as likely.
"No matter how old they are, once they hit 110, they still die at the same rate," Raftery said. "They’ve overcome all the things that life throws at you, like illnesses. They die for reasons that are somewhat independent of what affects younger people.
"This is a very select group of very robust people."
