For much of the 20th century, the average lifespan in developed countries increased steadily, adding about three years each decade. By the early 2000s, people born in places like Japan, Sweden, and Australia could expect to live 30 years longer than those born a century earlier. It seemed like this upward trend might continue indefinitely — but we all should have known better.

New research suggests that we may have hit a life expectancy ceiling, regardless of what tech gurus told you.

“We’re squeezing less and less life out of these life-extending technologies,” said S. Jay Olshansky, a professor at the University of Illinois at Chicago and lead author of the study. “And the reason is, aging gets in the way.”

The Limits of Longevity

Olshansky and his colleagues at The University of Illinois, Harvard University, and the University of California analyzed data from the Human Mortality Database, focusing on eight nations with some the highest life expectancies — Japan, South Korea, Australia, France, Italy, Switzerland, Sweden, and Spain — as well as the U.S. and Hong Kong. Their findings were stark. After decades of rapid increases in life expectancy, the rate of improvement has slowed dramatically in most of these countries since 1990. In some cases, like the U.S., life expectancy has even declined.

This deceleration comes despite ongoing medical advancements aimed at extending life. In many wealthy countries, public health measures like vaccinations, antibiotics, and improved sanitation helped to push life expectancy upward. But according to Olshansky, these gains can’t go on forever without addressing aging itself. “Our bodies don’t operate well when you push them beyond their warranty period,” he says.

It seems like the low-hanging fruit of life expectancy has been plucked. What we’re left with are marginal gains from increasingly costly interventions.

Exceeding the Warranty

This “warranty period” idea is not new. In fact, Olshansky predicted it all the way back in 1990, when he published a controversial study in Science, warning that increases in life expectancy would eventually plateau. His predictions were met with skepticism at the time, but now, decades later, the data seem to support his hypothesis.

As life expectancy increases, so do the challenges of old age like frailty, heart disease and dementia. Olshansky likens this process to playing a never-ending game of Whac-a-Mole. “Each mole represents a different disease,” he told Scientific American. “The longer people live, the more moles come up, and the faster they come up.”

This latest study found that in the world’s longest-lived country, Hong Kong, only 12.8% of female children and 4.4% of male children born in 2019 are expected to reach 100. In the U.S., the figures are even lower — 3.1% of girls and just 1.3% of boys are expected to become centenarians.

The Reality Check for Radical Life Extension

The findings challenge some of the more optimistic predictions of radical life extension. When the researchers calculated projected life expectancy if the population had kept up with the pace of 20th-century life extension, they found that 6% of Japanese women would live to the age of 150 and around 20% of Japanese women would live past age 120 — something that’s “ridiculous”, Olshansky added. The oldest person ever whose age has been independently verified is Jeanne Calment (1875–1997) of France, who lived to the age of 122 years and 164 days.

The concept of radical life extension, as defined in the study, refers to an annual increase in life expectancy of at least 0.3 years — adding three full years per decade. While countries like South Korea and Hong Kong showed some progress in the 1990s, the study found that these improvements have since plateaued. No country has sustained the pace of change necessary to suggest that radical life extension is occurring.

Achieving life expectancy close to 110 years, the researchers noted, would require dramatic reductions in mortality at all ages — a feat that seems impossible with current medical technology. In fact, the study points out that, to reach these extreme ages, over 70% of women and 24% of men would need to survive to 100 years, while a substantial percentage would need to live past 120.

“What this paper will hopefully do is impose a reality check on the field,” Eric Verdin, CEO of the Buck Institute for Research on Aging, who was not involved in the study, told STAT News. “Talking about things that are unattainable sells books, and it generates clicks, but it also detracts from the serious work that can be done now.”

Shifting the Focus from Lifespan to Health Span

Olshansky and many others in the field argue that instead of chasing radical life extension, scientists should focus on increasing the number of years people live in good health, known as “health span.” It’s about quality over quantity, ensuring that people enjoy a higher standard of living in their later years. It’s better than simply extending life at all costs if that means living with horrendous diseases.

Research into geroscience, a field dedicated to understanding and combating aging itself, is still in its infancy. But there are early signs of progress. “A deeper understanding of the protective influences and mechanisms underlying exceptional health span could lead to the development of novel therapeutic targets and interventions to promote healthy aging,” said Nalini Raghavachari from the U.S. National Institute on Aging.

There is much room for improvement. A 2017 study found that between 1990 and 2016, the number of years people lived with significant limitations from disease or injury grew from 8.2 years to 9.3 years globally. In other words, people are living longer, but not necessarily better.

Living to 150?

The new research adds weight to the growing body of evidence that life expectancy gains are slowing down, even in the wealthiest countries with the most advanced medical care. For some, like Steven Austad at the University of Alabama at Birmingham, who has long argued that the first person to live to 150 may already have been born, this may come as a surprise.

Austad and Olshansky have been engaged in friendly rivalry for decades. Austad bet that the first 150-year-old is currently alive today, while Olshansky betted against it. They made headlines in 2000 when the two experts on aging staked $300 (and more recently doubled the sum to $600) in an investment fund and signed a contract stating that the money and any returns would be paid to the winner (or his descendants) in 2150. The sum may seem trivial but if their investment fund grows at its current at of 9.5% per year, the winning pot could reach $200 million by 2150.

Olshansky though already considers the bet won. He believes his findings underscore that we’re approaching the upper limits of life expectancy and that it’s time to shift the focus to making those last years count. “I see our current lives as a celebration of success in medicine and medical technology,” Olshansky told STAT. “We really need to rejoice in what we’ve done.”

The findings appeared in the journal Nature Aging.