Maximum Life Span - in Humans

In Humans

The longest-living person whose dates of birth and death were verified to the modern norms of Guinness World Records and the Gerontology Research Group was Jeanne Calment, a French woman who lived to 122. The maximum (recorded) life span for humans has increased from 103 in 1798 to 110 years in 1898, 115 years in 1990, and 122.45 years since Calment's death in 1997 (See List of the verified oldest people and List of verified supercentenarians who died before 1980.), among steady improvements in overall life expectancy. Reduction of infant mortality has accounted for most of this increased average longevity, but since the 1960s mortality rates among those over 80 years have decreased by about 1.5% per year. "The progress being made in lengthening lifespans and postponing senescence is entirely due to medical and public-health efforts, rising standards of living, better education, healthier nutrition and more salubrious lifestyles." Animal studies suggest that further lengthening of human lifespan could be achieved through "calorie restriction mimetic" drugs or by directly reducing food consumption. Although calorie restriction has not been proven to extend the maximum human life span, as of 2006, results in ongoing primate studies are promising.

No fixed theoretical limit to human longevity is apparent today. "A fundamental question in aging research is whether humans and other species possess an immutable life-span limit." "The assumption that the maximum human life span is fixed has been justified, is invalid in a number of animal models and ... may become invalid for humans as well." Studies in the biodemography of human longevity indicate a late-life mortality deceleration law: that death rates level off at advanced ages to a late-life mortality plateau. That is, there is no fixed upper limit to human longevity, or fixed maximal human lifespan. This law was first quantified in 1939, when researchers found that the one-year probability of death at advanced age asymptotically approaches a limit of 44% for women and 54% for men.

It has also been observed that the VO₂max value (a measure of the volume of oxygen flow to the cardiac muscle) decreases as a function of age. Therefore, the maximum lifespan of an individual can be determined by calculating when his or her VO₂max value drops below the basal metabolic rate necessary to sustain life ---approximately 3 ml per kg per minute. Noakes (p. 84) notes that, on the basis of this hypothesis, athletes with a VO₂max value between 50 and 60 at age 20 can be expected "to live for 100 to 125 years, provided they maintained their physical activity so that their rate of decline in VO₂max remained constant. Of course, the reason few athletes ever achieve such longevity is that disease intervenes."

A theoretical study suggested the maximum human lifespan to be around 125 years using a modified stretched exponential function for human survival curves.