How long can humans live? Debate erupts after oldest person dies

Paris:

The death of the world’s oldest man at age 118 has reignited a debate that has divided scientists for centuries: How long can a healthy human live?

Following the death last week of French nun Lucile Randon, 115-year-old Spanish great-grandmother Maria Branyas Moreira has assumed the title of oldest living person, according to Guinness World Records.

In the 18th century, the French naturalist Georges-Louis Leclerc, better known as the Comte de Buffon, theorized that a person who had not suffered an accident or illness could theoretically live up to 100 years. Is.

Since then, medical advances and improvements in living conditions have pushed the limit back a few decades.

A new milestone was reached when Frenchwoman Jeanne Calment celebrated her 120th birthday in 1995.

Calment died two years later at the age of 122. She remains the oldest person ever to live – at least as verified.

According to the United Nations, there will be an estimated 593,000 people aged 100 or older in 2021, up from 353,000 a decade ago.

According to Statista data agency, the number of centenarians is expected to more than double in the next decade.

Comte de Buffon may also be surprised by the rise of supercentenarians — people aged 110 or older — whose numbers have been rising since the 1980s.

Natural limit at 115?

So how far can we go? Scientists disagree, some saying that the lifespan of our species is limited by strict biological constraints.

In 2016, geneticists writing in the journal Nature stated that there had been no improvement in human longevity since the 1990s.

Analyzing global demographic data, they found that the maximum human lifespan has declined since Calment’s death – even though there were more elderly people in the world.

“They concluded that there is a natural limit to the human lifespan and that longevity is limited to about 115 years,” French demographer Jean-Marie Robin told AFP.

“But this hypothesis is partly disputed by several studies,” said Mr. Robin, an expert on centenarians at the INSERM medical research institute.

Research in 2018 found that while the death rate increases with age, it slows down after 85.

Research states that around the age of 107, the mortality rate peaks at 50-60 percent every year.

“Under this theory, if there are 12 people aged 110, six will live to 111, three to 112, and so on,” Mr Robin said.

a numbers game

But the more supercentenarians there are, the more likely it is that some will have to live to make it to a record age.

If there are 100 supercentenarians, “50 will live to 111 years, 25 to 112,” Mr. Robin said.

“Thanks to a ‘quantity effect,’ there is no longer a fixed limit to longevity.”

However, Mr. Robin and his team are publishing research this year that will show that death rates continue to rise after age 105, narrowing the window further.

Does this mean that there is a hard limit to how long we can live? Mr. Robin won’t go that far.

“We will continue to make discoveries as always, and gradually improve the health of the most elderly people,” he added.

Other experts are also cautious about choosing sides.

“At the moment there is no definite answer,” said France Mesle, a demographer at the French Institute of Demographic Studies (INED).

“Even though they are increasing, the number of people reaching very old age is still very small and we still cannot make any significant statistical estimates,” he told AFP.

So it may be a matter of waiting for an increasing number of ultracenturies to test the “quantity effect”.

And surely some future medical breakthrough may soon change everything we know about death.

Eric Boulanger, a French doctor specializing in the elderly, said that “genetic manipulation” could allow some people to live to be 140 or 150 years old.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)