Does the Human Lifespan Have a Limit?

This is a question that remains the subject of debate to this day. A French philosopher and mathematician Nicolas de Condorcet asked in the late 18th century: “No doubt man will not become immortal”, “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? 

According to Jean-Marie Robine, a demographer at INSERM, France’s National biomedical research institute in Paris, 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. 

One of the first efforts to map the boundaries of human lifespan came from the British mathematician and actuary Benjamin Gompertz in 1825. His analysis of demographic records demonstrated that after a person’s late twenties, their risk of dying increased at an exponential rate year after year, suggesting that there is a horizon where that risk finally reaches 100%. 

The United Nations estimates that there were 573,000 centenarians alive worldwide in 2020 — more than 20 times the number 50 years earlier. 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.

According to researchers one of the biggest challenges when studying supercentenarians pertains to poor, or even deceptive record keeping, with some being clerical errors or the product of confused reports by extremely elderly individuals with memory problems. 

Steven Austad, a gerontologist at the University of Alabama at Birmingham, says that if the plateau is real, the number of living 110-year-olds required to produce a survivor beyond that age would roughly double for each successive year of longevity. “This means the odds of anybody getting to be more than about 120 or 125 are vanishingly small.” “It’s not really the limit that people who talk about limits think about, but it’s also not immortality.”

The continuous advance in science and healthcare have extended life expectancy over the years and could potentially increase the odds of individuals reaching an extreme old age by creating ever-larger numbers of centenarians. 

In a publication, Vaupel noted that life expectancies in Sweden and Japan had increased by as much as 3 months per year since 1840.  

Some experts say that there is robust evidence that we might be experiencing a phenomenon known as compression of mortality, in which populations are generally surviving to older ages without meaningfully pushing the outer limits of longevity. 

Some studies have suggested that interventions that tweak metabolic activity or alterations to the diet can confer significant longevity gains in species such as flies, worms, and even mice. But experts also point out that the problem is that the longer a species lives in general, the less longevity benefit there is to be expected from any intervention.


Original Source:

Michael Eisenstein. (2022, Jan 19). Does the human lifespan have a limit? Nature. Retrieved from: https://www.nature.com/articles/d41586-022-00070-1 

Image from: 

https://www.guinnessworldrecords.es/news/2019/3/worlds-oldest-person-confirmed-as-116-year-old-kane-tanaka-from-japan