In 1997, Jeanne Calment set the record for the longest recorded time a person has lived, passing away at the age of 122 years old. So far, no one has broken this record.
But even before Calment, the 20th Century heralded the last radical expansion of human lifespans thus far, spawning what some researchers call the “longevity revolution” by skyrocketing our chances of living longer. Thanks largely to improvements in medicine and public health measures, the average life expectancy is no longer capped below 50.
Now, as we make our way through the 21st Century, the question is no longer whether we can live longer but how much longer.
Do we Have a Lifespan Limit?
In the 1990s, during which Calment was still alive, most scientists believed humans were approaching a hypothetical limit, according to Natalia Gavrilova, a senior research associate at the Center on the Demography and Economics of Aging at the University of Chicago.
But when Gavrilova and her co-author Leonid Gavrilov looked at the data, she said, “Contrary to our expectations, we observed not an acceleration but rather a deceleration of mortality rates at older ages, eventually leveling off. This finding suggested that there is no fixed limit to the human lifespan.”
Upon revisiting the hypothesis in a study later published in 2020, Gavrilova found a similar pattern, though she noticed a new phenomenon as well: Mortality rates accelerated much more steeply after the age of 113 than at younger ages, which may explain why few have hit Calment’s record. Whether that’s due to something innate in our biology, Gavrilova says it’s still too early to draw conclusions.
Today’s Lifespans
That brings us to now. Thanks to ongoing breakthroughs in medicine and technology, the average person can live longer. But edging up the maximum age is going slower, according to David Sinclair, professor of genetics at Harvard Medical School’s Paul F. Glenn Center for Biology of Aging Research.
A statistical study published in 2021 found that there is only a 13 percent chance that an individual might reach the age 130 this century, suggesting that even if lifespans don’t have a hard limit, falling short could simply be a matter of practicality.
But to Nir Barzilai, director of the Institute for Aging Research at the Albert Einstein College of Medicine, the question of lifespan limitations isn’t a controversial issue. Simply put, it may look like there’s a limit now, but it doesn’t have to be.
Today, the gap between when the average person dies and when a centenarian breaks 100 years provides a ripe area for researchers to explore interventions for aging.
“We die, on average, before the age of 80,” Barzilai says. “Now, whether this limit can be broken in the future, it may or it may not. I would say we probably will be able to un-limit it sometime in the future — maybe not in my life. Maybe in yours.”
Factors that Impact Longevity
The prevailing piece of advice when it comes to living longer and healthier is to watch your lifestyle.
“For all of us at any age, exercise or movement, nutrition, sleep, and social connectivity can be optimized,” Barzilai says. “When you optimize that, they really help in the aging process.”
But there may also be factors deeper in our DNA that predispose someone to live long past today’s average life expectancy.
“Our studies of centenarians revealed that the strongest predictors of personal longevity are the lifespans of one’s parents,” writes Gavrilova.
Recent research increasingly points to the fact that lifestyle seems to matter less, the older someone gets. A 2017 study in the journal Extremes found that while lifestyle matters in getting people to an older age in the first place, it made no statistically significant differences in survival rates at extreme ages.
According to Barzilai, about 60% of centenarians have alterations in growth hormone genes that essentially slow their growth and let them better deal with the breakdowns of aging.
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The Promise of Longevity Genes
Sinclair also works on longevity genes, specifically the sirtuins that govern human epigenomes. The information stored in epigenomes is essential for maintaining cellular identity and function — they decide which toggles to switch on and off, ensuring that a brain cell remains a brain cell and not a skin cell.
Sinclair theorizes that epigenomes may provide an in for scientists to intervene in the aging process, due to their connections with bodily functions. His lab’s experiments in mice, published in Cell in 2023, have so far shown that disrupting epigenomes can accelerate aging — and recovering information could turn it back.
“If you have less epigenetic change and your cells express the right genes for longer, then you would be healthier and therefore live longer,” Sinclair says.
He caveats that there is still debate over whether epigenomes are the key aging drivers, and efforts to replicate results in humans are still ongoing, but they can be effective predictors for health.
Are There Benefits to Living Longer?
The most common question that Sinclair and researchers like him grapple with is not necessarily how to achieve longevity — but why bother.
While it may be perceived that longer-living humans will only further drain already limited resources, Sinclair argues that the improvements in life quality, driven by increased longevity, will be critical for boosting social productivity and happiness.
That doesn’t mean denying death’s eventual arrival but rather having more time to do what we love — which, for Sinclair, is finding an answer to this problem.
Read More: Life Expectancy Is Increasing in the U.S., Approaching Pre-Pandemic Levels
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