While life expectancy and lifespan has steadily increased during the 20th century, the maximum length of human life may already have been reached, according to a study published Wednesday in the British journal Nature.
“Our results strongly suggest that the maximum lifespan of human beings is fixed and subject to natural constraints,” write a group of American researchers, led by Jan Vijg who studied the maximum age reached in forty countries.
This is not the first time that researchers have been interested in the issue. In 2014, a French study had already shown that the life expectancy among high-level athletes as well as among the “super-centenarians” (people over 110 years) has maxed out. No super-centenarian has so far managed to match or surpass the longevity record of the French woman Jeanne Calment, who died in 1997 at the age of 122 years old.
By studying the “super-centenarians” in four countries (France, Japan, UK and USA), the US researchers found that the maximum age increased rapidly between 1970 and 1990 before reaching a plateau in 1995. After that date the maximum age at death began to decline slightly, in the order of 0.38 year annually between 1995 and 2006.
“Since the death of Jeanne Calment, the deans of humanity have been dying around 115 years and we predict that this should not change in the foreseeable future,” said Brandon Milholland, one of the authors of the study.
“Almost impossible to achieve 125 years”
Though the chances of living 125 years are very small, it is not impossible.“It is possible that someone might live slightly longer, but the odds of anybody in the world surviving to 125 in any given year is less than one in 10,000,” he said.
Life expectancy has increased dramatically during the 20th century, along with a rapid decline in infant mortality as well as improved sanitation, recalled the experts.
However, although today a growing number of people live beyond the age of 70 in forty countries for which data are available, the increase of the number of people living past 100 years plateaued and began a downward trend by the 1980.
The researchers acknowledge that their findings “suggest but do not prove that the human lifespan could have a natural limit.” “Further progress in the fight against infectious and chronic diseases could increase the average life expectancy of the population but not the maximum duration of life” noted Dr. Vijg.
To extend human longevity beyond the limit of 125 years would require “advanced therapies” capable of “controlling many genetic variants that seem to collectively determine the duration of human life,” he added. “As a scientist, it is our duty to tell the truth, even if it is not entirely pleasant” said Milholland. According to him, people in search of immortality “can continue to put their hopes in undiscovered technologies” to overcome current limitations.