Is there a limit to human life span? This question fascinates experts, especially since the considerable advances thatlife expectancy had the last century. Medical and public health advances have increased overall life expectancy by an additional three years every decade, from about 30 years in 1900 to about 73 years in 2020.
But most of this increase has occurred in rich countries, which have access to better health care and a better quality of life. However, life expectancy is no longer increasing in these countries, and overall life expectancy is only increasing due to other countries catching up. Based on this observation, researchers from the University of Illinois in the United States have concluded that the maximum lifespan has already been reached in some countries, and therefore that there is indeed a limit to human lifespan. Their results were published on October 7, 2024 in the journal Nature Aging.
Life expectancy stagnates in rich countries
The researchers looked closely at life expectancy data in the eight countries with the highest life expectancy measurement: Australia, France, Italy, Japan, South Korea, Spain, Sweden, and Switzerland, in addition to Hong Kong and the United States. In all of these countries, life expectancy has not been increasing as fast since 1990, except for Hong Kong, where it stagnated after 2000. On average, life expectancy in these countries increased by 6.5 years between 1990 and 2019. And it may even be falling in the United States!
From these data, the researchers estimated that only 5.1 percent of women and 1.8 percent of men in these countries will reach age 100. That's because the increase in life expectancy mainly reflects a decline in mortality among younger people, rather than a marked increase in longevity among older people. And the distribution of lifespans is beginning to flatten, showing that even the wealthiest people, with better access to health care, are not living much longer than other seniors.
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Life expectancy unlikely to increase radically
In these countries, life expectancy is currently about 85 years, 88 years for women and 83 years for men. Completely eradicating all mortality before the age of 50 would increase their life expectancy by only less than two years.
And for women's life expectancy to reach 110 years one day (since they are closer to it than men), it would be necessary to almost completely eliminate all causes of mortality! For their life expectancy to reach this age, 70% of women would have to reach at least 100 years, 24% would have to exceed the record set by Jeanne Calment (122 years) and 6% would have to reach 150 years! This is unlikely, to tell the truth.
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“ Humanity's quest to extend lifespan is coming to an end"
However, the number of centenarians will probably increase further, driven by the aging of society. The authors predict an acceleration of this increase, especially during the 2040s, about 100 years after the beginning of the Baby boom after World War II. But it will still be unlikely that the majority of people will be able to reach 100 years of life.
“ These results suggest that humanity's quest to extend lifespan is coming to an end., the authors conclude. This is not a pessimistic view... on the contrary, it is a celebration of the successes of more than a century of public health and medicine that have enabled humanity to overcome most of the causes that previously limited life expectancy."
However, these data cannot take into account the impact that the new technologies, currently under study, could have on human longevity. So while the "natural" increase in human life expectancy may already be over, a new longevity revolution may be on the horizon in the near future. But until we can modulate the biological process of aging, it is very unlikely that human lifespans will increase significantly any further.
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