The prospect of immortality may not be off the table for us humans, as life expectancies across the world continue to rise and defy all claims that they’ve already peaked. At least, that’s the conclusion of a new, not yet peer-reviewed study which suggests that our years may not be numbered by any natural limit.
Penned by a pair of researchers from the Human Evolutionary Ecology Group at the University of Zurich, the unpublished study begins by re-interpreting the results of a paper published last year, which demonstrated that increases in life expectancy in the world’s richest nations have slowed dramatically over the past 30 years. However, the authors point out that this fails to take into account gains made in other countries, where human lifespans are catching up with those in wealthier nations and could soon overtake them.
“The underlying logic is straightforward and applies to countless contexts,” they write. For instance, “the energy efficiency of combustion engines, processing speed of microchips, or even the standard of professional tennis underwent undeniable progress over the last decades; nonetheless, the world’s best car engine manufacturer, microchip producer, or professional tennis player have successively changed.”
“By the same token, successive advances in medicine and social welfare may not occur in the same country,” they explain. In other words, just because life expectancies are no longer surging like they once were in certain countries, there’s no reason why they can’t continue to do so elsewhere.
To highlight this point, the researchers point out that over the past two decades, the nation with the highest male life expectancy has changed six times, while the name at the top of the female life expectancy leaderboard has changed four times.
Using information from the Human Mortality Database, which contains longevity data from 41 countries, the study authors found that male lifespans increased by 1.96 years per decade between 2000 and 2020, which isn’t far off the 2.03 years per decade seen since 1840. The life expectancy of women, meanwhile, increased by 1.45 years per decade during the first 20 years of this century.
This may be considerably lower than the 2.31 years of extra longevity attained by women per decade since 1840, but still doesn’t support the claim that we’ve stopped living longer. Indeed, based on the current rate of improvement, the study authors predict that female lifespans will increase from the current average of 87.75 years to 100 years by 2063.
Overall, the researchers state that, contrary to previous claims, “both female and male lifespans continue to linearly increase at a global scale.”
“This remarkably long trend observed since 1840 remains at odds with our expectation that human lifespans must at some point hit a biologically imposed ceiling,” they write.
The study is currently available as a preprint on bioRxiv.
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