Maximum life span
232786
225711082
2008-07-15T00:58:07Z
Phenylalanine
5382478
fixed wikilinks
'''Maximum life span''' is a measure of the maximum amount of time one or more members of a group has been observed to survive between birth and death.
==Definition==
In animal studies, maximum life span is often taken to be the [[mean life span]] of the most long-lived 10% of a given [[cohort study|cohort]]. By another definition, however, maximum life span corresponds to the age at which the oldest known member of a [[species]] or experimental group has died. Calculation of the maximum life span in the former sense depends upon initial sample size.<ref>[[Leonid A. Gavrilov]] & [[Natalia S. Gavrilova]] (1991), ''The Biology of Life Span: A Quantitative Approach''. New York: Harwood Academic Publisher, ISBN 3-7186-4983-7</ref>
''Maximum life span'' is in contrast with'' [[mean life span]] ([[average life span]]'' or ''[[life expectancy]]).'' [[Mean life span]] varies with susceptibility to disease, [[accident]], [[suicide]] and [[murder|homicide]], whereas maximum life span is determined by "rate of aging".
==In humans==
The [[oldest people|oldest recognized person]] on record is [[Jeanne Calment]], a [[French people|French woman]] who lived for 122 years and 164 days. Maximum life span for humans has remained about 115−120 calendar years throughout recorded history, despite steady improvements in [[life expectancy]]. Reduction of infant mortality has accounted for most of this increased average [[longevity]], but since the 1960s [[mortality rate]]s among those over 80 years has decreased by about 1.5% per year. Advances in medicine, [[calorie restriction]] with adequate nutrition, or other interventions are said to have slowed the [[Senescence|aging process]]. Although calorie restriction has not been proven to extend the maximum human life span, as of 2006, results in ongoing primate studies are promising<ref>[http://www.springerlink.com/content/414023423x477815 SpringerLink - Journal Article<!-- Bot generated title -->]</ref>.
Identical [[twin]]s tend to die within 3 years of each other {{Fact|date=April 2008}}, whereas fraternal twins tend to die within 6 years {{Fact|date=April 2008}}. [[Senescence|Aging theories]] associated with [[DNA]] include programmed aging (or programmed aging-resistance) and theories that link aging with DNA damage/mutation or [[DNA repair]] capability.
==In other animals==
Small animals such as [[bird]]s and [[squirrel]]s rarely live to their maximum life span, usually dying of [[accident]]s and [[disease]]. Grazing animals show wear and tear to their teeth to the point where they can no longer eat, and they die of [[starvation]].
The maximum life span of most species has not been accurately determined, because the data collection has been minimal and the number of species studied in captivity (or by monitoring in the wild) has been small.
Maximum life span is usually longer for species that are larger, can fly, and have larger brains. When we look at primates, of the approximately 20,000 to 25,000 genes in the human [[genome]], it is estimated that 6% of these are different from those of a chimpanzee, which, in contrast to the human lifespan, has an average lifespan of only 52 years. The difference in [[longevity]] between humans and chimps could be due to as few as a hundred [[gene]]s or less; however there may be other factors that shorten the life span of chimpanzees.
The differences between life span between species demonstrate the role of [[genetics]] in determining maximum life span ("rate of aging"). The records (in years) are these:
*for [[mouse|mice]], 4 {{Fact|date=April 2008}}
*for [[dog]]s, 29, [[Aging_in_dogs#Factors_affecting_life_expectancy|in Australia]]
*for [[cat]]s, 36.<ref>{{cite web | title = Feline Statistics | url = http://www.pawsonline.info/feline_statistics.htm | accessdate = 2005-08-15}}</ref>;
*for [[goldfish]], 49<ref>[http://webspace.ship.edu/gspaul/animal%20behavior/goldfish%20foraging/intro_goldfish_foraging.html], [http://store.koistation.com/goldfish.html]</ref>
*for [[Horse#Age|horse]]s, 62
*for [[chimpanzee]]s, 76 ([[Cheeta]])
*for [[elephant]]s, 86 {{Fact|date=April 2008}}
The longest-lived vertebrates have been variously described as
*[[tortoise]]s ([[Galápagos tortoise]]) (190 years) {{Fact|date=April 2008}}
*[[whale]]s ([[Bowhead Whale]]) (about 211 years)
:Although this idea was considered specious for a time, recent research has indicated that [[bowhead whale]]s recently killed still had [[harpoon]]s in their bodies from the 1790s, which, along with analysis of [[amino acids]], has indicated a maximum life span, so far, of at least 211 years <ref>[http://www.johnfry.com/bada1.html Bada Whales<!-- Bot generated title -->]</ref>.
Invertebrate species which continue to grow as long as they live (''e.g.,'' certain clams, some coral species) can on occasion live hundreds of years:
* A [[Bivalvia|bivalve mollusc]] (''[[Arctica islandica]]'') (between 405-410 years<ref>http://www.newsdaily.com/Science/UPI-1-20071028-18102000-bc-britain-clam-crn.xml</ref>)
==In plants==
[[Plant]]s are referred to as [[Annual plant|annuals]] which only live one year, [[Biennial plant|biennials]] which live two years, and [[Perennial plant|perennials]] which live longer than that. The longest-lived perennials, woody-stemmed plants such as trees and bushes, often live for hundreds and even thousands of years (one may question whether or not they may die of old age). A [[giant sequoia]], [[General Sherman (tree)|General Sherman]] is alive and well in its second [[millennium]]. A [[Great Basin Bristlecone Pine]] called [[Methuselah (tree)|Methuselah]] is 4,838 years old and the Bristlecone Pine called [[Prometheus (tree)|Prometheus]] was a little older still, 4,844 years, when it was cut down in 1964.
==Increasing maximum life span==
Currently, the only (non-[[Genetically modified organisms|transgenic]]) method of increasing maximum life span that is recognized by [[Gerontology|biogerontologists]] is [[calorie restriction]] with adequate nutrition. "Maximum life span" here means the mean life span of the most long-lived 10% of a given cohort, as caloric restriction has not yet been shown to break mammalian world records for longevity. [[Rat]]s, [[mouse|mice]], and [[hamster]]s experience maximum life-span extension from a diet that contains 40–60% of the calories (but all of the required nutrients) that the animals consume when they can eat as much as they want. [[Mean life span]] is increased 65% and maximum life span is increased 50%, when caloric restriction is begun just before [[puberty]].<ref>{{cite journal | author=Koubova J, Guarente L. | title=How does calorie restriction work? | journal=Genes & Development | volume=17 | issue=3 | year=2003 | pages=313–321 | url=http://www.genesdev.org/cgi/content/full/17/3/313 |pmid=12569120 | doi=10.1101/gad.1052903}}</ref>). For [[fruit flies]] the life extending benefits of calorie restriction are gained immediately at any age upon beginning calorie restriction and ended immediately at any age upon resuming full feeding<ref>{{cite journal | author=Mair W, Goymer P, Pletcher SD, Partridge L. | title=Demography of dietary restriction and death in Drosophila | journal=[[Science (journal)|SCIENCE]] | volume=301 | issue=5640 | year=2003 | pages=1731–1733 | pmid=114500985 | doi=10.1126/science.1086016 }}</ref>).
Mammals fed [[anti-oxidant]]s show up to a 30% increase in [[mean life span]], but no increase in maximum life span. [[Antioxidants]] are most valuable for animals that are cancer-prone or subjected to [[radiation]] or [[chemical]] toxins. There are evidently homeostatic mechanisms in cells that govern the amount of allowable antioxidant activity. Many [[Life extension|life-extensionists]] have dismissed the value of antioxidants simply because they have not been shown to increase maximum life span, but such a view neglects the significance of an extended [[mean life span]].
On the other hand [[Michael Ristow]]'s laboratory has recently shown that [[antioxidants]] may prevent extension of [[life span]]. Increased activity of [[intracellular]] [[organelle]]s named [[mitochondria]] due to impaired metabolism of the nutritive sugar [[glucose]] extends [[life span]] of a model organism, the worm [[Caenorhabditis elegans]]. This extension occurs (completely unexpectedly) by increasing [[oxidative stress]] due to increased [[mitochondria]]l activity. Most importantly the life-extending effect of the low-sugar [[diet]] is abolished by various [[antioxidant]]s, suggesting that induction of [[oxidative stress]] may be required for health and extended [[life expectancy]]. <ref>[http://www.cellmetabolism.org/content/article/abstract?uid=PIIS1550413107002562 Publication demonstrating that oxidative stress is promoting life span]</ref> This latter process has been previously named [[mitohormesis]] or [[mitochondria]]l [[hormesis]] on a purely [[hypothetical]] basis, <ref>[http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=16242247 Publication that first used the term mitohormesis]</ref> and suggests that increased [[mitochondria]]l activity and specifically generation of [[oxidative stress]] due to this metabolic increase exert positive biological effects ultimately promoting health. These findings fundamentally question the hypothesis of [[Denham Harman]], and provide a mechanistic basis for the questionable use of [[antioxidants]] in humans. <ref>[http://jama.ama-assn.org/cgi/content/full/297/8/842 Publication demonstrating negative effects of antioxidants on human health]</ref>
Many [[Genetically modified organisms|transgenic]] species of mice have been created that have maximum life spans greater than that of wild-type or laboratory mice, including Ames dwarf mice, Snell dwarf mice, mice with increased [[mitochondria]]l [[catalase]], and others.
Some biomedical [[Gerontology|gerontologists]] (gerontologists who search for ways to extend maximum life span) believe that [[biomedical]] [[molecular]] [[engineering]] can someday extend maximum lifespan and even bring about [[Rejuvenation (aging)|rejuvenation]].
One such researcher is [[Aubrey de Grey]], who calls his project to reverse the damage called ''aging'' [[Strategies for Engineered Negligible Senescence|SENS]] ([[Strategies for Engineered Negligible Senescence|Strategies for Engineered Negligible Senescence]]). Dr. de Grey has established the [[The Methuselah Mouse Prize]] to award money to researchers who can extend the maximum life span of mice.
==Research data concerning maximum life span==
* A comparison of the [[heart]] [[mitochondria]] in rats (4-year maximum life span) and [[pigeon]]s (35-year maximum life span) showed that pigeon [[mitochondria]] leak fewer [[radical (chemistry)|free-radicals]] than rat mitochondria, despite the fact that both animals have similar [[metabolic rate]] and [[cardiac]] output<ref>{{cite journal | author=Herrero A, Barja G. | title=Sites and mechanisms responsible for the low rate of free radical production of heart mitochondria in the long-lived pigeon | journal=Mechanisms Of Aging And Development | volume=98 | issue=2 | year=1997 | pages=95–111 | pmid=9379714 | doi=10.1016/S0047-6374(97)00076-6}}</ref>
* For [[mammal]]s there is a direct relationship between [[mitochondria]]l [[cell membrane|membrane]] [[fatty acid]] saturation and maximum life span<ref>{{cite journal | author=Pamplona R, Portero-Otin M, Riba D, Ruiz C, Prat J, Bellmunt MJ, Barja G. | title=Mitochondrial membrane peroxidizability index is inversely related to maximum life span in mammals | journal=Journal Of Lipid Research | volume=39 | issue=2 | year=1998 | pages=1989–1994 | url=http://www.jlr.org/cgi/content/full/39/10/1989 | pmid=9788245 }}</ref>
* Studies of the [[liver]] [[lipid]]s of [[mammal]]s and a [[bird]] ([[pigeon]]) show an inverse relationship between maximum life span and number of [[double bond]]s<ref>{{cite journal | author=Pamplona R, Portero-Otin M, Riba D, Requena JR, Thorpe SR, Lopez-Torres M, Barja G. | title=Low fatty acid unsaturation: a mechanism for lowered lipoperoxidative modification of tissue proteins in mammalian species with long life spans | journal=JOURNALS OF GERONTOLOGY SERIES A BIOLOGICAL SCIENCES AND MEDICAL SCIENCES | volume=55A | issue=6 | year=2000 | pages=B286–B291 | pmid=10843345 }}</ref>
* Selected species of [[bird]]s and [[mammal]]s show an inverse relationship between [[telomere]] rate of change (shortening) and maximum life span<ref>{{cite journal | author=Haussmann MF, Winkler DW, O'Reilly KM, Huntington CE, Nisbet IC, Vleck CM | title=Telomeres shorten more slowly in long-lived birds and mammals than in short-lived ones | journal=Proceedings. Biological Sciences / The Royal Society| volume=270 | issue=1522 | year=2003 | pages=1387–1392 | pmid=12965030 | doi=10.1098/rspb.2003.2385 }}</ref>
* Maximum life span correlates negatively with [[antioxidant]] [[enzyme]] levels and correlates positively with lower rate of [[radical (chemistry)|free-radicals]] production and higher rate of [[DNA repair]]<ref>{{cite journal | author=Perez-Campo R, Lopez-Torres M, Cadenas S, Rojas C, Barja G. | title=The rate of free radical production as a determinant of the rate of aging: evidence from the comparative approach. | journal=JOURNAL OF COMPARATIVE PHYSIOLOGY. B, Biochemical, systemic, and environmental physiology | volume=168 | issue=3 | year=1998 | pages=149–158 | pmid=9591361 | doi=10.1007/s003600050131}}</ref>
* Females express both more Mn−SOD and more glutathione peroxidase antioxidant [[enzyme]]s than males, and this has been suggested to be the reason females live longer than males in [[mammal]]ian species<ref>{{cite journal | author=Vina J, Borras C, Gambini J, Sastre J, Pallardo FV. | title=Why females live longer than males? Importance of the upregulation of longevity-associated genes by oestrogenic compounds | journal=Febs Letters | volume=579 | issue=12 | year=2005 | pages=2541–2545 | pmid=15862287 | doi=10.1016/j.febslet.2005.03.090}}</ref>
* The maximum life span of [[Genetically modified organism|transgenic]] mice has been extended about 20% by overexpression of human [[catalase]] targeted to [[mitochondria]]<ref>{{cite journal | author=Schriner SE, Linford NJ, Martin GM, Treuting P, Ogburn CE, Emond M, Coskun PE, Ladiges W, Wolf N, Van Remmen H, Wallace DC, Rabinovitch PS. | title=Extension of murine life span by overexpression of catalase targeted to mitochondria | journal=[[Science (journal)|SCIENCE]] | volume=308 | issue=5730 | year=2005 | pages=1909–1911 | pmid=15879174 | doi=10.1126/science.1106653 }}</ref>
* A comparison of 7 non-[[primate]] [[mammal]]s (mouse, hamster, rat, guinea-pig, rabbit, pig and cow) showed that the rate of [[mitochondrial]] superoxide and hydrogen peroxide production in [[heart]] and [[kidney]] were inversely correlated with maximum life span<ref>{{cite journal | author=Ku HH, Brunk UT, Sohal RS. | title=Relationship between mitochondrial superoxide and hydrogen peroxide production and longevity of mammalian species | journal=Free Radical Biology & Medicine | volume=15 | issue=6 | year=1993 | pages=621–627 | pmid=8138188 | doi=10.1016/0891-5849(93)90165-Q}}</ref>
* A study of 8 non-[[primate]] [[mammals]] showed a direct correlation between maximum life span and oxidative damage to mtDNA ([[Mitochondrial DNA]]) in heart & brain<ref>{{cite journal | author=Barja G, Herrero A. | title=Oxidative damage to mitochondrial DNA is inversely related to maximum life span in the heart and brain of mammals | journal=The Faseb Journal | volume=14 | issue=2 | year=2000 | pages=312–318 | url=http://www.fasebj.org/cgi/content/full/14/2/312 | pmid=10657987 }}</ref>
* A study of several species of mammals and a bird (pigeon) indicated a linear relationship between oxidative damage to protein and maximum life span<ref>{{cite journal | author=Agarwal S, Sohal RS. | title=Relationship between susceptibility to protein oxidation, aging, and maximum life span potential of different species | journal=Experimental Gerontology | volume=31 | issue=3 | year=1996 | pages=365–372 | pmid=9415119 | doi=10.1016/0531-5565(95)02039-X}}</ref>
* There is a direct correlation between [[DNA repair]] and maximum life span for [[mammal]]ian species<ref>{{cite journal | author=Cortopassi GA, Wang E. | title=There is substantial agreement among interspecies estimates of DNA repair activity | journal=Mechanisms Of Aging And Development | volume=91 | issue=3 | year=1996 | pages=211–218 | pmid=9055244 | doi=10.1016/S0047-6374(96)01788-5}}</ref>
* [[Drosophila]] (fruit-flies) bred for 15 generations by only using eggs that were laid toward the end of reproductive life achieved maximum life spans 30% greater than that of controls<ref>{{cite journal | author=Kurapati R, Passananti HB, Rose MR, Tower J. | title=Increased hsp22 RNA levels in Drosophila lines genetically selected for increased longevity | journal=JOURNALS OF GERONTOLOGY SERIES A BIOLOGICAL SCIENCES AND MEDICAL SCIENCES | volume=55A | issue=11 | year=2000 | pages=B552–B559 | pmid=11078089 }}</ref>
* Overexpression of the [[enzyme]] which synthesizes [[glutathione]] in long-lived [[Genetically modified organism|transgenic]] [[Drosophila]] (fruit-flies) extended maximum lifespan by nearly 50%<ref>{{cite journal | author=Orr WC, Radyuk SN, Prabhudesai L, Toroser D, Benes JJ, Luchak JM, Mockett RJ, Rebrin I, Hubbard JG, Sohal RS | title=Overexpression of glutamate-cysteine ligase extends life span in Drosophila melanogaster | journal=The Journal Of Biological Chemistry | volume=280 | issue=45 | year=2005 | url=http://www.jbc.org/cgi/content/full/280/45/37331 | pages=37331–37338 | pmid=16148000 | doi=10.1074/jbc.M508272200}}</ref>
* A mutation in the '''age−1''' gene of the [[nematode]] [[worm]] [[Caenorhabditis elegans]] increased [[mean life span]] 65% and maximum life span 110%<ref>{{cite journal | author=Friedman DB, Johnson TE. | title=A mutation in the age-1 gene in Caenorhabditis elegans lengthens life and reduces hermaphrodite fertility | journal=GENETICS | volume=118 | issue=1 | year=1988 | pages=75–86 | url=http://www.genetics.org/cgi/reprint/118/1/75 | pmid=8608934}}</ref>
* [[Fat]]-specific [[Insulin]] [[receptor (biology)|Receptor]] [[Gene knockout|KnockOut]] ('''FIRKO''') mice have reduced fat mass, normal calorie intake and an increased maximum life span of 18%<ref>{{cite journal | author=Bluher M, Kahn BB, Kahn CR. | title=Extended longevity in mice lacking the insulin receptor in adipose tissue | journal=[[Science (journal)|SCIENCE]] | volume=299 | issue=5606 | year=2003 | pages=572–574 | pmid=12543978 | doi=10.1126/science.1078223 }}</ref>
* The capacity of mammalian species to detoxify the [[carcinogenic]] chemical [[Benzopyrene|benzo(a)pyrene]] to a water-soluble form also correlates well with maximum life span<ref>{{cite journal | author=Moore CJ, Schwartz AG. | title=Inverse correlation between species lifespan and capacity of cultured fibroblasts to convert benzo(a)pyrene to water-soluble metabolites | journal=Experimental Cell Research | volume=116 | issue=2 | year=1978 | pages=359–364 | pmid=101383 | doi=10.1016/0014-4827(78)90459-7}}</ref>
* Short-term induction of [[oxidative stress]] due to [[calorie restriction]] increases life span in [[Caenorhabditis elegans]] by promoting stress defense, specifically by inducing an [[enzyme]] called [[catalase]]. As shown by [[Michael Ristow]] and co-workers nutritive [[antioxidant]]s completely abolish this extension of life span by inhibiting a process called '''[[mitohormesis]]'''. <ref>[http://www.cellmetabolism.org/content/article/abstract?uid=PIIS1550413107002562 Publication demonstrating that oxidative stress is promoting life span]</ref>
==See also==
* [[Aging]]
* [[American Aging Association]]
* [[Aubrey de Grey]]
* [[Gerontology]]
* [[Biodemography]]
* [[Biological immortality]]
* [[Calorie restriction]]
* [[DNA damage theory of aging]]
* [[Strategies for Engineered Negligible Senescence]] (SENS)
* [[Indefinite lifespan]]
* [[Life expectancy]]
* [[Life extension]]
* [[List of long-living organisms]]
* [[Longevity]]
* [[Methuselah Mouse Prize]]
* [[Michael Ristow]]
* [[Mitohormesis]]
* [[Oldest people]]
* [[Senescence]]
==References==
<!-- ----------------------------------------------------------
See http://en.wikipedia.org/wiki/Wikipedia:Footnotes for a
discussion of different citation methods and how to generate
footnotes using the<ref>, </ref> and <reference /> tags
----------------------------------------------------------- -->
{{reflist}}
==External links==
*[http://genomics.senescence.info/species/ AnAge Database]
*[http://www.viadeicentenari.it/ENG/centenariansroadproject.htm Centenarians’ Road]
* [http://www.calorierestriction.org/ Calorie Restriction Society]
* [http://www.senescence.info/ Informational website on the biology of aging.]
* [http://transcripts.cnn.com/TRANSCRIPTS/0512/30/acd.02.html/ Living Longer, Living Stronger]
* [http://www.benbest.com/lifeext/aging.html Mechanisms of Aging]
* [http://www.sens.org/ Strategies for Engineered Negligible Senescence (SENS)]
* [http://www.wonderquest.com/LifeSpan-MaxMin.htm The animals with the longest and shortest life spans]
* [http://www.longevitymeme.org/ The Longevity Meme (Longevity Activism)]
* [http://www7.nationalgeographic.com/ngm/0511/feature1/ The Secrets of Long Life (National Geographic magazine)]
{{Longevity}}
[[Category:Actuarial science]]
[[Category:Aging]]
[[Category:Demography]]
[[Category:Gerontology]]
{{link FA|uk}}
[[ru:Максимальная продолжительность жизни]]
[[uk:Максимальна тривалість життя]]