Life expectancy gains have slowed sharply, study finds

Researchers Track a Century of Longevity Data

The study, published in the Proceedings of the National Academy of Sciences, was conducted by Héctor Pifarré i Arolas of the La Follette School of Public Affairs, José Andrade of the Max Planck Institute for Demographic Research, and Carlo Giovanni Camarda of the Institut national d’études démographiques. Drawing from the Human Mortality Database, the researchers examined data from 23 high-income, low-mortality countries using six independent methods to forecast mortality trends.

According to Pifarré i Arolas, “The unprecedented increase in life expectancy we achieved in the first half of the 20^th century appears to be a phenomenon we are unlikely to achieve again in the foreseeable future. In the absence of any major breakthroughs that significantly extend human life, life expectancy would still not match the rapid increases seen in the early 20th century even if adult survival improved twice as fast as we predict.”

A Century of Uneven Gains

Between 1900 and 1938, life expectancy in wealthy nations rose by roughly five and a half months per generation. Someone born in 1900 could expect to live an average of 62 years, while a person born in 1938 could expect to reach about 80 years — a dramatic improvement over just a few decades.

For generations born between 1939 and 2000, however, progress slowed to around two and a half to three and a half months per generation, depending on the statistical model used. Mortality forecasting models — analytical tools that predict future lifespans using past and present mortality data — allowed the researchers to project multiple possible futures for human longevity.

“We forecast that those born in 1980 will not live to be 100 on average, and none of the cohorts in our study will reach this milestone. This decline is largely due to the fact that past surges in longevity were driven by remarkable improvements in survival at very young ages,” according to corresponding author Andrade.

In the early 20th century, rapid declines in infant mortality — brought about by medical innovation, improved sanitation, and higher living standards — significantly boosted average life expectancy. Today, infant and child mortality rates in high-income countries are already extremely low, meaning future gains must come from improved survival at older ages. The study concludes that such advances are unlikely to match the explosive pace of progress achieved a century ago.

Implications for Policy, Healthcare, and Planning

Although forecasts can never be fully certain, the authors emphasize that their results provide essential insights for policymakers preparing for the future. Unexpected developments such as new pandemics, medical breakthroughs, or major societal shifts could alter these trends, but current evidence suggests a long-term slowdown.

This slowdown has consequences that go beyond national statistics. While the study focuses on populations rather than individuals, slower life expectancy growth may influence how people approach saving, retirement, and long-term care. As Pifarré i Arolas and his colleagues suggest, both governments and individuals may need to adjust their expectations and plans for the decades ahead.