Editing Maximum life span (section)

==In humans==
{{Main|Oldest people|List of the verified oldest people}}

=== Demographic evidence ===
The [[oldest people|longest living person]] whose dates of birth and death were verified according to the modern norms of ''[[Guinness World Records]]'' and the [[Gerontology Research Group]] was [[Jeanne Calment]] (1875–1997), a Frenchwoman who is verified to have lived to 122. The oldest male lifespan has only been verified as 116, by Japanese man [[Jiroemon Kimura]]. Reduction of infant mortality has accounted for most of the increased average life span [[longevity]], but since the 1960s [[mortality rate]]s among those over 80 years have decreased by about 1.5% per year. According to [[James Vaupel]], "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."<ref>{{cite journal | vauthors = Vaupel JW | title = Biodemography of human ageing | journal = Nature | volume = 464 | issue = 7288 | pages = 536–42 | date = March 2010 | pmid = 20336136 | pmc = 4010874 | doi = 10.1038/nature08984 | bibcode = 2010Natur.464..536V }}</ref> Animal studies suggest that further lengthening of median human lifespan as well as maximum lifespan could be achieved through "[[Caloric restriction mimetic|calorie restriction mimetic]]" drugs or by directly reducing food consumption.<ref>{{cite journal | vauthors = Ben-Haim MS, Kanfi Y, Mitchell SJ, Maoz N, Vaughan KL, Amariglio N, Lerrer B, de Cabo R, Rechavi G, Cohen HY | title = Breaking the Ceiling of Human Maximal Life span | journal = The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences | volume = 73 | issue = 11 | pages = 1465–1471 | date = October 2018 | pmid = 29121176 | doi = 10.1093/gerona/glx219 | pmc = 6454488 }}</ref> Although calorie restriction has not been proven to extend the maximum human life span {{asof|2014|lc=y}}, results in ongoing primate studies have demonstrated that the assumptions derived from rodents are valid in primates.<ref>''Nature'', 1 April 2014.</ref><ref>{{cite journal | vauthors = Ingram DK, Roth GS, Lane MA, Ottinger MA, Zou S, de Cabo R, Mattison JA | title = The potential for dietary restriction to increase longevity in humans: extrapolation from monkey studies | journal = Biogerontology | volume = 7 | issue = 3 | pages = 143–8 | date = June 2006 | pmid = 16732404 | doi = 10.1007/s10522-006-9013-2 | s2cid = 2859875 | url = https://zenodo.org/record/1232785 }}</ref>

It has been proposed that no fixed theoretical limit to human longevity is apparent today.<ref>{{Cite book | vauthors = Gavrilov LA, Gavrilova NS | year = 1991 | title = The Biology of Life Span: A Quantitative Approach | location = [[New York City]] | publisher = Starwood Academic Publishers }}{{Page needed|date=January 2018}}</ref><ref>{{Cite journal | journal = Population Dev Rev | volume = 26 | issue = 2 | pages = 403–04 | title = Book Reviews: ''Validation of Exceptional Longevity'' | last1 = Gavrilov | first1 = Leonid A. | last2 = Gavrilova | first2 = Natalia S. | name-list-style = vanc | date = June 2000 | url = http://longevity-science.org/PDR-00.pdf | access-date = 2009-05-18 }}</ref> 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.<ref>{{Cite web |url=http://longevity-science.org/Biodemography.html |title=Biodemography of Human Longevity |last=Gavrilov |first=Leonid A. | name-list-style = vanc
|date=5 March 2004 |publisher=International Conference on Longevity |access-date=2018-01-13}}</ref> 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.<ref>{{Cite journal | url = http://longevity-science.org/Greenwood-Human-Biology-1939.pdf | vauthors = Greenwood M, Irwin JO | date = 1939 | title = The Biostatics of Senility | journal = Human Biology | volume = 11 | pages = 1–23 | access-date = 2009-05-18 }}</ref>

However, this evidence depends on the existence of a late-life plateaus and deceleration that can be explained, in humans and other species, by the existence of very rare errors.<ref>{{cite journal | vauthors = Gavrilova NS, Gavrilov LA | title = Mortality Trajectories at Extreme Old Ages: A Comparative Study of Different Data Sources on U.S. Old-Age Mortality | journal = Living to 100 Monograph | volume = 2014 | date = 2014 | pmid = 25664347 | pmc = 4318539 }}</ref><ref name=":2">{{cite journal | vauthors = Newman SJ | title = Errors as a primary cause of late-life mortality deceleration and plateaus | journal = PLOS Biology | volume = 16 | issue = 12 | pages = e2006776 | date = December 2018 | pmid = 30571676 | doi = 10.1371/journal.pbio.2006776 | pmc = 6301557 | doi-access = free }}</ref> Age-coding error rates below 1 in 10,000 are sufficient to make artificial late-life plateaus, and errors below 1 in 100,000 can generate late-life mortality deceleration. These error rates cannot be ruled out by examining documents<ref name=":2" /> (the standard) because of successful pension fraud, identity theft, forgeries and errors that leave no documentary evidence. This capacity for errors to explain late-life plateaus solves the "fundamental question in aging research is whether humans and other species possess an immutable life-span limit" and suggests that a limit to human life span exists.<ref>{{cite journal | vauthors = Wilmoth JR, Deegan LJ, Lundström H, Horiuchi S | title = Increase of maximum life-span in Sweden, 1861-1999 | journal = Science | volume = 289 | issue = 5488 | pages = 2366–8 | date = September 2000 | pmid = 11009426 | doi = 10.1126/science.289.5488.2366 | bibcode = 2000Sci...289.2366W }}</ref>
A theoretical study suggested the maximum human lifespan to be around 125 years using a modified [[stretched exponential function]] for human survival curves.<ref>{{cite journal | vauthors = Weon BM, Je JH | title = Theoretical estimation of maximum human lifespan | journal = Biogerontology | volume = 10 | issue = 1 | pages = 65–71 | date = February 2009 | pmid = 18560989 | doi = 10.1007/s10522-008-9156-4 | s2cid = 8554128 }}</ref>
In another study, researchers claimed that there exists a maximum lifespan for humans, and that the human maximal lifespan has been declining since the 1990s.<ref name=":0">{{cite journal | vauthors = Dong X, Milholland B, Vijg J | title = Evidence for a limit to human lifespan | journal = Nature | volume = 538 | issue = 7624 | pages = 257–259 | date = October 2016 | pmid = 27706136 | doi = 10.1038/nature19793 | bibcode = 2016Natur.538..257D | s2cid = 3623127 | pmc = 11673931 }}</ref> A theoretical study also suggested that the maximum human [[life expectancy]] at birth is limited by the human life characteristic value δ, which is around 104 years.<ref>{{cite journal | vauthors = Liu X | title = Life equations for the senescence process | journal = Biochemistry and Biophysics Reports | volume = 4 | pages = 228–233 | date = December 2015 | pmid = 29124208 | pmc = 5669524 | doi = 10.1016/j.bbrep.2015.09.020 | arxiv = 1502.00759 }}</ref>

In 2017, the [[United Nations]] conducted a Bayesian sensitivity analysis of global population burden based on life expectancy projection at birth in future decades. The 95% prediction interval of average life expectancy rises as high as 106 years old by 2090, with ongoing and layered effects on world population and demography should that happen. However, the prediction interval is extremely wide.<ref>Castanheira, H., Pelletier, F. and Ribeiro, I. (2017). A Sensitivity Analysis of the Bayesian Framework for Projecting Life Expectancy at Birth, UN Population Division, Technical Paper No. 7. New York: United Nations.</ref>

=== Non-demographic evidence ===

Evidence for maximum lifespan is also provided by the dynamics of physiological indices with age. For example, scientists have observed that a person's [[VO2 max|VO<sub>2</sub>max]] value (a measure of the volume of oxygen flow to the cardiac muscle) decreases as a function of age. Therefore, the maximum lifespan of a person could be determined by calculating when the person's VO<sub>2</sub>max value drops below the basal metabolic rate necessary to sustain life, which is approximately 3&nbsp;[[millilitre|ml]] per [[kilogram|kg]] per minute.<ref name="Nokes Lore">{{Cite book | vauthors = Noakes T | year = 1985 | title = The Lore of Running | publisher = Oxford University Press }}</ref>{{Page needed|date=January 2018}} On the basis of this hypothesis, athletes with a VO<sub>2</sub>max value between 50 and 60 at age 20 would be expected "to live for 100 to 125 years, provided they maintained their physical activity so that their rate of decline in VO<sub>2</sub>max remained constant".<ref>Nokes (1985) p. 84.</ref>

[[File: Age dynamics of the body mass.svg|thumb|Average and commonly accepted maximum lifespans correspond to the extremums of the body mass (1, 2) and mass normalized to height (3, 4) of men (1, 3) and women (2, 4).<ref name="Age dynamics">{{cite journal| vauthors = Gerasimov IG, Ignatov DY |title=Age Dynamics of Body Mass and Human Lifespan| journal = Journal of Evolutionary Biochemistry and Physiology | volume = 40 | issue = 3| pages = 343–349|year=2004| doi = 10.1023/B:JOEY.0000042639.72529.e1 |s2cid=9070790}}</ref>]]