Eternal youth
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Eternal youthis the concept of human physicalimmortalityfree ofageing.Theyouthreferred to is usually meant to be in contrast to the depredations of aging, rather than a specific age of the human lifespan. Eternal youth is common in mythology, and is a popular theme infiction.
Religion and mythology
[edit]Eternal youth is a characteristic of the inhabitants ofParadiseinAbrahamic religions.
The Hindus believe that the Vedic and the post-Vedic rishis have attained immortality, which implies the ability to change one's body's age or even shape at will. These are some of thesiddhasinYoga.Markandeyais said to always stay at the age of 16.
The difference between eternal life and the more specific eternal youth is a recurrent theme inGreekandRoman mythology.Themythemeof requesting the boon of immortality from a god, but forgetting to ask for eternal youth appears in the story ofTithonus.A similar theme is found inOvidregarding theCumaean Sibyl.
InNorse mythology,Iðunnis described as providing the godsapplesthat grant them eternal youthfulness in the 13th-centuryProse Edda.
Telomeres
[edit]An individual'sDNAplays a role in the aging process. Aging begins even before birth, as soon as cells start to die and need to be replaced. On the ends of eachchromosomeare repetitive sequences of DNA,telomeres,that protect the chromosome from joining with other chromosomes, and have several key roles. One of these roles is to regulate cell division by allowing each cell division to remove a small amount of genetic code. The amount removed varies by the cell type being replicated. The gradual degradation of the telomeres restricts cell division to 40–60 times, also known as theHayflick limit.Once this limit has been reached, more cells die than can be replaced in the same time span. Thus, soon after this limit is reached the organism dies. The importance of telomeres is now clearly evident: lengthen the telomeres, lengthen the life.[1]
However, a study of the comparative biology of mammalian telomeres indicated that telomere length correlates inversely, rather than directly, with lifespan, and concluded that the contribution of telomere length to lifespan remains controversial.[2]Also, telomere shortening does not occur with age in some postmitotic tissues, such as in the rat brain.[3]In humans, skeletal muscle telomere lengths remain stable from ages 23–74.[4]In baboon skeletal muscle, that consists of fully differentiated post-mitotic cells, less than 3% of myonuclei contain damaged telomeres and this percentage does not increase with age.[5]Thus telomere shortening does not appear to be a major factor in the aging of the differentiated cells of brain or skeletal muscle.
Studies have shown that 90 percent ofcancercells contain large amounts of anenzymecalledtelomerase.[6]Telomerase is an enzyme that replenishes the worn away telomeres by adding bases to the ends and thus renewing the telomere. A cancer cell has in essence turned on the telomerase gene, and this allows them to have an unlimited amount of divisions without the telomeres wearing away. Other kinds of cells that can surpass the Hayflick limit arestem cells,hair follicles,andgerm cells.[7]This is because they contain raised amounts of telomerase.
Therapy
[edit]The idea that the human body can be repaired in old age to a more youthful state has gathered significant commercial interest over the past few years, including by companies such asHuman Longevity Inc,Google Calico,andElysium Health.[8][9][10]In addition to these larger companies, many startups are currently developing therapeutics to tackle the 'ageing problem' using therapy.[11][12]In 2015 a new class of drugssenolyticswas announced (currently in pre-clinical development) designed specifically to combat the underlying biological causes of frailty.[13]
Philanthropy
[edit]The "loss of youth" or ageing process is responsible for increasing the risk of individuals to many diseases includingcancer,Parkinson's,Alzheimer's,and others. As a result, in recent years, many high net worth individuals have donated large amounts of their money towards initiatives towards scientific research into the ageing process itself or therapies to slow or reverse the ageing process.[14]These people includeJeff Bezos,Ray Kurzweil,Peter Thiel,[15]Aubrey de Grey,Larry Ellison,Sergey Brin,Dmitry Itskov,Paul Gallen,[16]andMark Zuckerberg.[17]
See also
[edit]References
[edit]- ^Lee J. Siegel."ARE TELOMERES THE KEY TO AGING AND CANCER?".Archived fromthe originalon 2013-01-20.
- ^Gomes NM, Ryder OA, Houck ML, Charter SJ, Walker W, Forsyth NR, Austad SN, Venditti C, Pagel M, Shay JW, Wright WE (2011)."Comparative biology of mammalian telomeres: hypotheses on ancestral states and the roles of telomeres in longevity determination".Aging Cell.10(5): 761–768.doi:10.1111/j.1474-9726.2011.00718.x.PMC3387546.PMID21518243.
- ^Cherif H, Tarry JL, Ozanne SE, Hales CN (2003)."Ageing and telomeres: a study into organ- and gender-specific telomere shortening".Nucleic Acids Res.31(5): 1576–1583.doi:10.1093/nar/gkg208.PMC149817.PMID12595567.
- ^Renault V, Thornell LE, Eriksson PO, Butler-Browne G, Mouly V (2003). "Regenerative potential of human skeletal muscle during aging".Aging Cell.1(2): 132–139.doi:10.1046/j.1474-9728.2002.00017.x.PMID12882343.S2CID7020102.
- ^Jeyapalan JC, Ferreira M, Sedivy JM, Herbig U (2007)."Accumulation of senescent cells in mitotic tissue of aging primates".Mech Ageing Dev.128(1): 36–44.doi:10.1016/j.mad.2006.11.008.PMC3654105.PMID17116315.
- ^Klaus Damm (2001)."A highly selective telomerase inhibitor limiting human cancer cell proliferation".The EMBO Journal.20(24): 6958–6968.doi:10.1093/emboj/20.24.6958.PMC125790.PMID11742973.
- ^Peter J. Hornsby (2007)."Telomerase and the aging process".Experimental Gerontology.42(7): 575–81.doi:10.1016/j.exger.2007.03.007.PMC1933587.PMID17482404.
- ^"Former unicorn genetics startup Human Longevity loses its horn".2018-12-11.RetrievedDecember 26,2018.
- ^"Google's Long, Strange Life-Span Trip".RetrievedDecember 26,2018.
- ^"The Anti-Aging Pill".RetrievedDecember 26,2018.
- ^"Esthechoc: Scientists invent 'anti-ageing' chocolate".
- ^"Startup Alkahest inks a $50M deal for anti-aging R&D".
- ^"New" Senolytic "Drugs Can Dramatically Increase Healthy Lifespan".11 March 2015.
- ^Wallace, Benjamin (August 23, 2016)."An MIT Scientist Claims That This Pill Is the Fountain of Youth".New York Magazine.
- ^"Billionaire Peter Thiel embarks on anti-aging crusade".
- ^"These Tech Billionaires Are Determined to Buy Their Way Out of Death".Business Insider.
- ^"Zuckerberg, Brin join forces to extend life".February 20, 2013.RetrievedAugust 8,2016.