United States: For as long as humanity has contemplated its inevitable demise, the enigma of whether a finite upper boundary exists to human longevity has persisted. This inquiry has spurred myriad unconventional methods, from transfusions of youthful blood to biotech tests that claim to reveal one’s “biological age.” It appears that many aspire to surpass the record set by Jeanne Calment, who lived to an unprecedented 122 years and 164 days, or to emulate the longevity of Maria Branyas, who, until her recent passing at 117 in a Spanish care home, held the title of the oldest living person.

For decades, longevity researchers have fiercely debated this query, and a new scholarly study, unveiled this week, has reignited the debate regarding whether human lifespans will perpetually extend or if a biological ceiling is indeed inescapable, according to salon.com.

The average human life expectancy has seen remarkable progression over the past century, doubling from a mere 32 years in 1900 to a global average of 71 years in 2021, as reported by Our World in Data. Revolutionary advancements in medical science and technological innovations have facilitated this surge, with lifespans in affluent nations steadily rising at a rate of approximately three years per decade throughout the 20th century.

However, the recent research published in Nature Aging asserted that this trajectory is decelerating. The study provocatively concludes that “humanity’s quest for an extended life has, for the most part, been fulfilled.” By analyzing data from eight affluent nations with the longest life expectancies, as well as the United States and Hong Kong, the researchers discovered that life expectancy growth significantly slowed between 1990 and 2019, as per salon.com.

The authors further noted that reaching the milestone of 100 years will remain a rarity. The probability of females reaching centenarian status hovers around 15 percent, while for males, it is a mere 5 percent unless there is a monumental shift in our understanding and deceleration of biological aging.

Among the countries studied, South Korea and Hong Kong were the only places that experienced a continuation of “radical life extension,” akin to the exponential growth witnessed in the 20th century—defined as an annual life expectancy increase of 0.3 years during the period analyzed.

Dr S. Jay Olshansky, one of the study’s authors and a public health professor at the University of Illinois at Chicago, attributes much of the longevity gains throughout the 20th century to groundbreaking medical interventions, such as vaccines and antibiotics, which primarily saved younger populations. These early-life interventions, he explained, led to a more pronounced increase in overall lifespan compared to recent advancements, which have predominantly benefited older adults, as per salon.com.

“In the field of epidemiology, we refer to this as competing risks,” Olshansky noted during a phone interview with Salon. “The older you become, the more conditions vie for your life. It’s akin to a game of Whac-a-Mole.”

Despite this slowing trend, the burgeoning global anti-aging industry—valued at $62 billion—underscores the enduring desire for extended lifespans. Changes in longevity reverberate across society, influencing retirement, the workforce, and eldercare. Although gains in life expectancy have decelerated in many wealthy nations, some researchers still anticipate a gradual upward trend, even if the pace has diminished. According to John Bongaarts of the Population Council in New York City, life expectancy in these affluent nations has risen by roughly six years per decade since 1960.

One notable exception is the United States, where life expectancy has declined in recent years, setting it apart from its peers. This anomaly is largely attributed to crises such as obesity, opioid overdoses, and maternal mortality, all of which occur at disproportionately high rates compared to other high-income nations.

“If you exclude the United States from the analysis, the other countries continue to show consistent gains in life expectancy, and that trend is expected to persist,” Bongaarts observed, according to salon.com.

While current medical advances continue to extend the lives of older individuals, Shripad Tuljapukar, a professor of biology and population studies at Stanford University, believes that although the pace of improvement may have slowed, the overall effect remains positive. His research, published in PNAS, indicates that older adults are not only living longer but are also increasingly outlasting conditions that would have claimed their lives in previous generations. He describes the trend as “a wave of survival advancing with age.”

Dr Olshansky’s recent findings echo those of a previous study he co-authored in 1990, titled “In Search of Methuselah: Estimating the Upper Limits to Human Longevity,” which posited that it was “highly improbable that life expectancy at birth would surpass 85 years.”

“I don’t believe we can replicate the exponential gains we saw in the past,” Olshansky remarked. “To extend a 90-year-old’s life by four or five decades would require breakthroughs of a magnitude we haven’t yet seen,” as per salon.com.

Yet, Japan, a nation frequently regarded as a bellwether for global life expectancy trends, has already surpassed the 85-year mark, particularly among women.

There is also growing discourse within the scientific community around the potential for advancements that could fundamentally alter the biology of aging. Some researchers are dedicated to exploring ways to reverse cellular aging, though the causes of aging remain a subject of intense debate. While some scholars view aging as a gradual, inevitable “rusting” process of the body’s cells, others, like Michael Rose, an evolutionary biology professor at the University of California, Irvine, reject this notion. Rose points to multicellular organisms that share fundamental cell biology with humans yet exhibit no signs of aging.

“There are experts in my field who firmly believe we can radically alter the course of aging and mortality,” Rose stated during an interview.

Ultimately, whether the elusive key to unlocking eternal youth is ever discovered remains uncertain. As Tuljapukar succinctly put it: “We may not have all the answers, but one thing is clear—more individuals will live to extraordinary ages in the future.”

And even if we never discover a definitive limit to human life, it’s plausible that more Jeanne Clements and Maria Branyas will emerge, their longevity etching new records into human history.