![]() One of the biggest challenges when studying supercentenarians pertains to poor - or even deceptive - record-keeping. But these findings also became a subject of strong contention. The team’s data indicated that the Gompertz curve actually plateaus at this extreme age 3, with mortality risk levelling off to a 50% chance of survival every subsequent year - thus reaching no firm longevity limit. ![]() Two years later, a group led by demographer Elisabetta Barbi at the Sapienza University of Rome challenged Vijg’s findings with a study of Italians over the age of 105. This proposal of a de facto maximum lifespan proved controversial, drawing numerous published responses that questioned both the statistical methods used and the interpretation of the results. A 2016 study 2 by geneticist Jan Vijg’s group at the Albert Einstein College of Medicine in New York City analysed the maximum reported ages of death in France, Japan, the United States and the United Kingdom, and concluded that survival past the age of 125 is exceedingly unlikely. These trends have fuelled debate about just how far we can go. The current longevity record is held by Jeanne Calment, a French woman who passed away in 1997 at the age of 122 years and five months (see ‘The rising age of the longest-living human’). And hundreds of people reached the rarefied ranks of the supercentenarians - aged 110 or older - although demographers have validated the records of only a fraction of them. The United Nations estimates that there were 573,000 centenarians alive worldwide in 2020 - more than 20 times the number 50 years earlier. ![]() Questions have emerged about the flexibility of Gompertz’s model as more and more people reach ages that were considered exceptional a few generations ago. However, the authors also speculated that medical advances in controlling senescence and treating chronic disease could theoretically bend the curve and make that limit a routine life expectancy in the future. In 1996, for example, a mathematical analysis 1 by Caleb Finch and Malcolm Pike at the University of Southern California in Los Angeles used the Gompertz model to estimate a maximum human lifespan of around 120 years - a reasonable ceiling, given that only one person had reached that age. His model still seems to accurately map the pattern of age-related mortality for a sizeable portion of the human lifespan, even though medical advances have shifted the timing somewhat. Almost 200 years later, Gompertz’s work remains influential. “Gompertz speculated that this was a law equivalent to Newton’s law of gravity,” says Jay Olshansky, an epidemiologist and gerontologist at the University of Illinois Chicago. His analysis of demogra-phic records demonstrated that after a person’s late twenties, their risk of dying increased at an exponential rate year after year - sugesting that there is a horizon where that risk finally reaches 100%. One of the first efforts to map the boundaries of human lifespan came from the British mathematician and actuary Benjamin Gompertz in 1825. ![]() Even if no formal physiological limit exists, reaching the frontiers of survival is no mean feat, and further gains in longevity might ultimately require remarkable advances in medical science, even if the ranks of the world’s centenarians continue to swell. “It is possibly the oldest research question we have,” he says. Jean-Marie Robine, a demographer at INSERM, France’s national biomedical research institute in Paris, points out that the limits of lifespan sparked curiosity long before Condorcet. ![]() “And now they’re refusing to cross that line, irrespective of what the accumulated evidence suggests.” “People have drawn a line in the sand with their particular vision of what old age is like,” says Steven Austad, a gerontologist at the University of Alabama at Birmingham. Arguments have often become heated, with research articles occasionally prompting angry letters to journal editors and even allegations of fraud. Some researchers posit that modern human lifespans are nearing a natural ceiling, whereas others see no evidence for such a limit. The answer to that question remains the subject of debate. “No doubt man will not become immortal,” he wrote in Sketch for a Historical Picture of the Progress of the Human Mind, “but cannot the span constantly increase between the moment he begins to live and the time when naturally, without illness or accident, he finds life a burden?” In the late eighteenth century, while in hiding from his fellow French revolutionaries, the philosopher and mathematician Nicolas de Condorcet posed a question that continues to occupy scientists to this day. Jeanne Calment became the world’s oldest person before she died in 1997 at the age of 122. ![]()
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