No one might ever challenge the 122-year record of the longest-living person in documented history, said a study Wednesday which claimed to have found a “ceiling” to maximum human lifespan.

Sifting through demographic data from more than 40 countries around the world, New York-based researchers found that an end to the long-running rise in maximum lifespan “has already been attained”, in the 1990s.

The plateau was reached in about 1997 — the year that Frenchwoman Jeanne Calment died at the unbeaten age of 122 years and 164 days.

“The trend since then has been for the oldest person in the world to be around 115 years old,” study co-author Brandon Milholland of the Albert Einstein College of Medicine said.

This was despite average life expectancy continuing to increase as medical care, nutrition and living conditions improved.

In other words, more people are living into old age these days, but exceptionally long-lived individuals were not getting quite as old as before.

“We predict this (trend) will remain stable for the foreseeable future,” said Milholland.

“It is possible that someone might live slightly longer (than 115) but the odds of anybody in the world surviving to 125 in any given year is less than one in 10,000.”

This could all be changed, of course, by a major medical or technological breakthrough — the long-sought elixir of life.

“We can’t eliminate the possibility of a breakthrough that will further extend lifespan, but it would have to be unlike anything seen before,” Milholland said.

“The medical advances of the past few decades may have increased life expectancy and quality of life, but they have not done anything to increase the maximum lifespan.”