Despite advances in medical technology, genetic research, and a growing number of centenarians, life expectancy gains are slowing down globally, according to a new study published in Nature Aging. Researchers found that in countries with the longest-living populations, increases in lifespan have plateaued, suggesting humanity may be nearing the upper limit of life expectancy.
Lead author S. Jay Olshansky, a researcher at the University of Illinois-Chicago, emphasized that it may be time to reassess expectations about longevity and related issues like retirement planning. “We have to recognize there’s a limit,” Olshansky stated. Mark Hayward, a University of Texas researcher not involved in the study, supported this view, noting that life expectancy improvements are hitting a plateau.
What is Life Expectancy?
Life expectancy estimates the average number of years a baby born in a given year might live, assuming current death rates remain constant. While it is a critical health metric, life expectancy cannot predict unforeseen events such as pandemics or groundbreaking medical discoveries.
In this study, Olshansky and his team examined life expectancy data from 1990 to 2019, focusing on countries with the longest-living populations, including Australia, France, Hong Kong, Italy, Japan, South Korea, Spain, and Switzerland. The U.S. was included for comparison, though it ranks outside the top 40 for life expectancy.
Who Lives the Longest?
Women continue to outlive men, but the pace of life expectancy improvement has slowed. While gains averaged 2.5 years per decade in 1990, they have fallen to 1.5 years in the 2010s, with almost no improvement in the U.S.
The U.S. faces unique challenges, including higher rates of death from drug overdoses, gun violence, obesity, and inequities in healthcare access. When researchers calculated the potential impact of eliminating all deaths before age 50 in these countries, the maximum life expectancy increase was only 1.5 years, suggesting that factors beyond early death prevention are now limiting lifespan gains.
The Limits of Life Expectancy
The study suggests that there may be a biological cap on how long most people can live. “We’re squeezing less and less life out of these life-extending technologies because aging gets in the way,” Olshansky explained.
Although the number of people living to 100 is likely to increase due to population growth, the percentage of those reaching that milestone will remain relatively small. For instance, in 2019, about 2% of Americans lived to 100, compared with 5% in Japan and 9% in Hong Kong. Experts predict that fewer than 15% of women and 5% of men will live to 100 in most countries.
The findings raise questions about how societies should plan for aging populations and manage expectations around health and longevity in the coming decades.
