Longevity is a term that generally refers to 'long life' or 'great duration of life'.[1] Reflections on longevity have usually gone beyond acknowledging the basic
shortness of human life and have included thinking about methods to extend life. Longevity has been a topic not only for the
scientific community but also for writers of travel, science fiction and utopian novels. There are many difficulties to
authenticate the longest human lifespan ever, because of inaccurate birth statistics in the past; though fiction, legend, and
mythology have proposed or claimed vastly longer lifespans in the past or future and longevity
myths frequently allege them to exist in the present.
The word 'longevity' is sometimes used as a synonym for 'life expectancy' in demography.
However, this is not the most popular or accepted definition, [2]. For the general public as well as writers, the word generally connotes 'long life', especially when
it concerns someone or something lasting longer than expected (an 'ancient tree', for example).
Presently
Various factors contribute to an individual's longevity. Significant factors in life expectancy include gender, genetics, access to health care, hygiene, diet, exercise, lifestyle, and crime rates. Below is a list of life expectancies in different types of
countries[3]:
Population longevities can be seen as increasing due to increases in life expectancies
around the world[4][3]:
- Spain:. . . . . 81.02 years in 2002, 82.31 years in 2005
- Australia: . . 80 years in 2002, 80.39 years in 2005
- Italy:. . . . . . 79.25 years in 2002, 79.68 years in 2005
- France: . . . .79.05 years in 2002, 79.60 years in 2005
- Germany: . . 77.78 years in 2002, 78.65 years in 2005
- UK: . . . . . . 77.99 years in 2002, 78.4 years in 2005
- USA: . . . . . 77.4 years in 2002, 77.7 years in 2005
The current validated longevity records can be found in the list of supercentenarians.
Notable individuals include:
- Jeanne Calment (1875-1997, 122 years and 164 days) - the oldest person in history whose age has been verified by modern documentation.
This defines the human lifespan, which is set by the oldest documented individual who ever
lived
- Shigechiyo Izumi (1865-1986, 120 years 237 days, disputed) - the oldest male ever recognized by the Guinness Book of World Records; this is widely questioned by scholars, who believe that
conflation of dates has occurred and this has compromised the authenticity of Izumi's age
- Christian Mortensen (1882-1998, 115 years 252 days) - the oldest male widely accepted by scholars.
History
Reaching an old age has fascinated people for ages. There are many organizations dedicated to exploring the causes behind
aging, ways to prevent aging, and ways to reverse aging. Despite the fact that it is no more than human nature to not wish to
surrender to old age and death, a few organizations are against antiaging, because they believe it sacrifices the best interests
of the new generation, that it is unnatural, or unethical. Others are dedicated towards it, seeing it as a form of
transhumanism and the pursuit of immortality. Even among those who do not wish for eternal life, longevity may be desired
to experience more of life, or to provide a greater contribution to humanity.
A remarkable statement mentioned by Diogenes Laertius (c. 250) is the earliest (or
at least one of the earliest) references about (plausible centenarian) longevity given by a scientist, the astronomer
Hipparchus of Nicea (c. 185 – c. 120 B.C.), who, according to the doxographer,
assured that the philosopher Democritus of Abdera (c. 470/460 – c. 370/360
B.C.) lived 109 years. All other account given by the ancients about the age of Democritus, appears to, without giving any
specific age, agree in the fact that the philosopher lived over 100 years; possibility that turns out to be likely given, not
only by the fact that many ancient Greek philosophers are thought to have lived over the age of 90 (e.g.: Xenophanes of Colophon, c. 570/565 – c. 475/470 B.C., Pyrrho of Ellis, c. 360
- c. 270 B.C., Eratosthenes of Cirene c. 285 – c. 190 B.C., etc.), but also because of the
difference that the case of Democritus evidences from the case of, for example, Epimenides of
Crete (VII, VI centuries B.C.) of whom it is said to have lived 154, 157 or 290 years, like it has been said about countless
elders even during the last centuries (as well as in present time) being these cases most likely (or at least in most cases),
exaggerations if not deliberate frauds.
Religion
- Further information: Longevity myths
The Bible contains many accounts of long-lived humans, the oldest being Methuselah living to be 969 years old (Genesis 5:27). Today some maintain
that the unusually high longevity of Biblical patriarchs are the result of an error in translation: lunar cycles were mistaken
for the solar ones, and that the actual ages being described would have been 12.4 times less (a lunar cycle being 29.5 days).
This makes Methuselah's age only 78. This rationalization, however, seems doubtful too since patriarchs such as Mahalalel (ibid
5:15) and Enoch (ibid 5:21) were said to have become fathers after 65 "years". If the lunar cycle claim were accepted this would
translate to an age of about 5 years and 3 months.
One Christian apologist claim is that the life span of humans has changed; that
originally man was to have everlasting life, but due to man's sin, God progressively shortened man's life in the "four falls of mankind" -- first to less than 1000
years, then to under 500, 200, and eventually 120 years. After those long living people died around the time of the Biblical
Flood, God decided that humans would not be permitted to live more than 120 years (Genesis 6:3.) However, since later biblical
figures (and more recent people) such as Sarah lived for longer than that, 120 years should be considered the "usual" upper limit
to man's lifespan. Some individuals can live slightly longer than that.
Another theory proposed by a self described “rational faith apologist” is based on the fact that some longevity specialists
propose that aging occurs primarily due to telomere shortening during cell replication. Each
time a cell replicates itself telomeres lose length until finally, replication cannot occur and the cells die. The theory
postulates that prior to the flood there existed a thick cloud cover as described in Genesis. This cover protected DNA from UV
and other radiation and their subsequent destructive mutation. Post flood with the cloud cover removed, UV rays and radiation
could have caused both DNA and cellular destruction; specifically the type that cause telomere shortening or accelerated telomere
shortening. As this mutation was passed on, shorter life spans would result for presumably both human and animals.
It has been hypothesized that there is a trade-off between cancerous tumor suppression and tissue repair capacity, and that by
lengthening telomeres we might slow aging and in exchange increase vulnerability to cancer (Weinstein and Ciszek, 2002).
Experimentation with telomeres on worms has yielded increased worm life spans by about 20% (Joeng et al., 2004). Even if further
study shows that telomeres specifically are not tied to aging, the concept that some sort of DNA damage can cause genetically
accelerated aging cannot be abandoned, thus providing a rational explanation for longevity and a subsequent reduction of
longevity post-flood.
Many cultures like the Sumerians and Indus Valley also document groups of people who lived many 100’s of years. Both cultures
show reduced life spans after the flood.[citation needed]
Furthermore, starting with reformers John Calvin and Martin Luther, an alternative explanation has arisen : 120 years would not refer to man's lifespan
but to the amount of time left before the flood.]
A more commonly accepted explanation is that such stories are longevity myths; age exaggeration tends to be greater in
"mythical" periods in many cultures; the early emperors of Japan or China often ruled for more than a century, according to
tradition. With the advent of modern accountable record-keeping, age claims fell to realistic levels; even later in the Bible
King David died at 70 years; other kings in their 30s, 40s, and 50s.
Future
The mainstream view on the future of longevity, such as the US Census Bureau, is that life expectancy in the USA will be in the mid-80s by 2050 (up from 77.85 in
2006) and will top out eventually in the low 90s, barring major scientific advances that can change
the rate of human aging itself, as opposed to merely treating the effects of aging as is done today. The Census Bureau also
predicted that the USA would have 5.3 million people aged over 100 in 2100 (Which means that, if
this turns out to be true, those people are children and toddlers today).
Recent increases in the rates of lifestyle diseases, such as obesity, diabetes, hypertension, and heart disease, may however drastically slow or
reverse this trend toward increasing life expectancy in the developed world.
Oeppen and Vaupel (see Science):1029, 2002) have observed that since 1840 record life expectancy
has risen linearly for men and women, albeit more slowly for men. For women the increase has been
almost three months/year. In light of steady increase, without any sign of a cap, the suggestion that life expectancy will top
out must be treated with caution. Oeppen and Vaupel observe that experts who assert that "life expectancy is approaching a
ceiling ... have repeatedly been proven wrong."It is thought that life expectancy for women increased more dramatically due to
the considerable increases in medicine related to childbirth.
Some argue that molecular nanotechnology will greatly extend human
lifespans. See medical nanotechnology.
Non-human biological longevity
Living:
Dead:
- Adwaitya - an Aldabra Giant Tortoise, died
2006 at between 150-255 years old, the oldest known animal.
- A Bowhead Whale killed in a hunt was found to be approximately 211 years old, the
longest lived mammal known.[1]
- Lamellibrachia luymesi, a deep-sea cold seep tubeworm, is estimated to reach
ages of over 250 years based on a model of its growth rates. [citation needed]
Scientific books on longevity
- Leonid A. Gavrilov & Natalia S. Gavrilova (1991), The
Biology of Life Span: A Quantitative Approach. New York: Harwood Academic Publisher, ISBN
- John Robbins' Healthy at 100 garners
evidence from many scientific sources to account for the extraordinary longevity of Abkhasians in the Caucasus, Vilcabambans in
the Andes, Hunzas in Central Asia, and Okinawans.
- Beyond The 120-Year Diet, by Roy L. Walford, M.D.
- Forever Young: A Cultural History of Longevity from Antiquity to the Present Door Lucian Boia,2004 ISBN 1861891547
Longevity in fiction
Notes
- ^ http://www.answers.com/topic/longevity?cat=health.
- ^ http://www.answers.com/topic/longevity?cat=health.
- ^ a b CIA World Fact Book
- ^ CIA World Fact Book 2002
See also
External links
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