We've seen dramatic increases in life expectancy over the 19th and 20th centuries, thanks to healthier diets, medical advances and many other quality-of-life improvements. But after nearly doubling over the course of the 20th century, the rate of increase has slowed considerably in the last three decades, according to a new study led by the University of Illinois Chicago. Despite frequent breakthroughs in medicine and public health, life expectancy at birth in the world's longest-living populations has increased only an average of six and a half years since 1990, the analysis found.
That rate of improvement falls far short of some scientists' expectations that life expectancy would increase at an accelerated pace in this century and that most people born today will live past 100 years. The Nature Aging paper, "Implausibility of Radical Life Extension in Humans in the 21st Century," offers new evidence that humans are approaching a biologically based limit to life. The biggest boosts to longevity have already occurred through successful efforts to combat disease, said lead author S.
Jay Olshansky of the UIC School of Public Health. That leaves the damaging effects of aging as the main obstacle to further extension. "Most people alive today at older ages are living on time that was manufactured by medicine," said Olshansky, a professor of epidemiology and biostatistics.
But these medical Band-Aids are producing fewer years of life even though they're occurring at an accelerated.