Life expectancy gains are slowing, study shows

The dramatic gains in life expectancy seen over the last two centuries are slowing, according to a new study.

Advances in medical technology and genetic research, not to mention larger numbers of people making it to age 100, are not translating into marked jumps in lifespan overall, according to researchers who found shrinking longevity increases in countries with the longest-living populations.

“We have to recognise there’s a limit” and perhaps reassess assumptions about when people should retire and how much money they’ll need to live out their lives, said S. Jay Olshansky, a University of Illinois-Chicago researcher who was lead author of the study published on Monday in the journal Nature Aging.

Mark Hayward, a University of Texas researcher not involved in the study, called it “a valuable addition to the mortality literature”.

“We are reaching a plateau” in life expectancy, Hayward said, and while it’s always possible some breakthrough could push survival to greater heights, we don’t have that now”.

What is life expectancy?

Life expectancy is an estimate of the average number of years a baby born in a given year might expect to live, assuming death rates at that time hold constant.

It is one of the world’s most important health measures, but it is also imperfect: It is a snapshot estimate that cannot account for deadly pandemics, miracle cures, or other unforeseen developments that might kill or save millions of people.

In the new research, Olshansky and his research partners tracked life expectancy estimates for the years 1990 to 2019, drawn from a database administered by the Max Planck Institute for Demographic Research in Germany.

The researchers focused on eight countries where people live the longest – Australia, France, Italy, Japan, South Korea, Spain, Sweden, and Switzerland – as well as Hong Kong and the United States, which doesn’t even rank in the top 40.

Who lives the longest?

Women continue to live longer than men and life expectancy improvements are still occurring – but at a slowing pace, the researchers found. In 1990, the average amount of improvement was about 2.5 years per decade, but that fell to 1.5 years in the 2010s.

In one calculation, the researchers estimated what would happen in these countries if all deaths before age 50 were eliminated.

The increase at best was still only 1.5 years, Olshansky said.

Eileen Crimmins, a University of Southern California gerontology expert, said in an email that she agrees with the study’s findings, adding that in her opinion, “the most important issue is the dismal and declining relative position of the United States”.

Why life expectancy may not be able to rise forever

The study suggests that there’s a limit to how long most people live, and we’ve about hit it, Olshansky said.

“We’re squeezing less and less life out of these life-extending technologies. And the reason is, ageing gets in the way,” he said.

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In 2019, a little over two per cent of Americans made it to 100, compared with about five per cent in Japan and nine per cent in Hong Kong, Olshansky said.

It’s likely that the ranks of centenarians will grow in the decades ahead, experts say, but that’s because of population growth.

The percentage of people hitting 100 will remain limited, likely with fewer than 15 per cent of women and five per cent of men making it that long in most countries, Olshansky said.