Life extension

Life extension science, also known as anti-aging medicine, indefinite life extension, experimental gerontology, and biomedical gerontology, is the study of slowing down or reversing the processes of aging to extend both the maximum and average lifespan. Some researchers in this area, and "life extensionists", "immortalists" or "longevists" (those who wish to achieve longer lives themselves), believe that future breakthroughs in tissue rejuvenation, stem cells, regenerative medicine, molecular repair, gene therapy, pharmaceuticals, and organ replacement (such as with artificial organs or xenotransplantations) will eventually enable humans to have indefinite lifespans (agerasia[1]) through complete rejuvenation to a healthy youthful condition.

The sale of purported anti-aging products such as nutrition, physical fitness, skin care, hormone replacements, vitamins, supplements and herbs is a lucrative global industry, with the US market generating about $50 billion of revenue each year.[2] Some medical experts state that the use of such products has not been proven to affect the aging process and many claims regarding the efficacy of these marketed products have been roundly criticized by medical experts, including the American Medical Association.[2][3][4][5][6]

The ethical ramifications of life extension are debated by bioethicists.

Average and maximum lifespans in humans and other organisms

Main article: Senescence

During the process of aging, an organism accumulates damage to its macromolecules, cells, tissues, and organs. Specifically, aging is characterized as and thought to be caused by "genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication."[7] Oxidation damage to cellular contents caused by free radicals is believed to contribute to aging as well.[8][8][9]

The longest a human has ever been proven to live is 122 years, the case of Jeanne Calment who was born in 1875 and died in 1997, whereas the maximum lifespan of a wildtype mouse, commonly used as a model in research on aging, is about three years.[10] Genetic differences between humans and mice that may account for these different aging rates include differences in efficiency of DNA repair, antioxidant defenses, energy metabolism, proteostasis maintenance, and recycling mechanisms such as autophagy.[11]

Average lifespan in a population is lowered by infant and child mortality, which are frequently linked to infectious diseases or nutrition problems. Later in life, vulnerability to accidents and age-related chronic disease such as cancer or cardiovascular disease play an increasing role in mortality. Extension of expected lifespan can often be achieved by access to improved medical care, vaccinations, good diet, exercise and avoidance of hazards such as smoking.

Maximum lifespan is determined by the rate of aging for a species inherent in its genes and by environmental factors. Widely recognized methods of extending maximum lifespan in model organisms such as nematodes, fruit flies, and mice include caloric restriction, gene manipulation, and administration of pharmaceuticals.[12] Another technique uses evolutionary pressures such as breeding from only older members or altering levels of extrinsic mortality.[13][14] Some animals such as hydra, planarian flatworms, and certain sponges, corals, and jellyfish do not die of old age and exhibit potential immortality.[15][16][17][18]

Theoretically, extension of maximum lifespan in humans could be achieved by reducing the rate of aging damage by periodic replacement of damaged tissues, molecular repair or rejuvenation of deteriorated cells and tissues, reversal of harmful epigenetic changes, or the enhancement of telomerase enzyme activity.[19][20]

Research geared towards life extension strategies in various organisms is currently under way at a number of academic and private institutions. Since 2009, investigators have found ways to increase the lifespan of nematode worms and yeast by 10-fold; the record in nematodes was achieved through genetic engineering and the extension in yeast by a combination of genetic engineering and caloric restriction.[21] A 2009 review of longevity research noted: "Extrapolation from worms to mammals is risky at best, and it cannot be assumed that interventions will result in comparable life extension factors. Longevity gains from dietary restriction, or from mutations studied previously, yield smaller benefits to Drosophila than to nematodes, and smaller still to mammals. This is not unexpected, since mammals have evolved to live many times the worm's lifespan, and humans live nearly twice as long as the next longest-lived primate. From an evolutionary perspective, mammals and their ancestors have already undergone several hundred million years of natural selection favoring traits that could directly or indirectly favor increased longevity, and may thus have already settled on gene sequences that promote lifespan. Moreover, the very notion of a "life-extension factor" that could apply across taxa presumes a linear response rarely seen in biology."[21]

Current strategies and issues

Diets and supplements

Much life extension research focuses on nutrition—diets or supplements—as a means to extend lifespan, although few of these have been systematically tested for significant longevity effects. The many diets promoted by anti-aging advocates are often contradictory. A dietary pattern with some support from scientific research is caloric restriction.[22][23]

Preliminary studies of caloric restriction on humans using surrogate measurements have provided evidence that caloric restriction may have powerful protective effect against secondary aging in humans. Caloric restriction in humans may reduce the risk of developing Type 2 diabetes and atherosclerosis.[24]

The free-radical theory of aging suggests that antioxidant supplements, such as vitamin C, vitamin E, Q10, lipoic acid, carnosine, and N-acetylcysteine, might extend human life. However, combined evidence from several clinical trials suggest that β-carotene supplements and high doses of vitamin E increase mortality rates.[25] Resveratrol is a sirtuin stimulant that has been shown to extend life in animal models, but the effect of resveratrol on lifespan in humans is unclear as of 2011.[26]

There are many traditional herbs purportedly used to extend the health-span, including a Chinese tea called Jiaogulan (Gynostemma pentaphyllum), dubbed "China's Immortality Herb."[27] Ayurveda, the traditional Indian system of medicine, describes a class of longevity herbs called rasayanas, including Bacopa monnieri, Ocimum sanctum, Curcuma longa, Centella asiatica, Phyllanthus emblica, Withania somnifera and many others.[27]

Hormone treatments

The anti-aging industry offers several hormone therapies. Some of these have been criticized for possible dangers to the patient and a lack of proven effect. For example, the American Medical Association has been critical of some anti-aging hormone therapies.[2]

Although some recent clinical studies have shown that low-dose growth hormone (GH) treatment for adults with GH deficiency changes the body composition by increasing muscle mass, decreasing fat mass, increasing bone density and muscle strength, improves cardiovascular parameters (i.e. decrease of LDL cholesterol), and affects the quality of life without significant side effects,[28][29][30] the evidence for use of growth hormone as an anti-aging therapy is mixed and based on animal studies. There are mixed reports that GH or IGF-1 signaling modulates the aging process in humans and about whether the direction of its effect is positive or negative.[31]

Scientific controversy regarding anti-aging nutritional supplementation and medicine

Some critics dispute the portrayal of aging as a disease. For example, Leonard Hayflick, who determined that fibroblasts are limited to around 50 cell divisions, reasons that aging is an unavoidable consequence of entropy. Hayflick and fellow biogerontologists Jay Olshansky and Bruce Carnes have strongly criticized the anti-aging industry in response to what they see as unscrupulous profiteering from the sale of unproven anti-aging supplements.[4]

Ethics and politics of anti-aging nutritional supplementation and medicine

Politics relevant to the substances of life extension pertain mostly to communications and availability.

In the United States, product claims on food and drug labels are strictly regulated. The First Amendment (freedom of speech) protects third-party publishers' rights to distribute fact, opinion and speculation on life extension practices. Manufacturers and suppliers also provide informational publications, but because they market the substances, they are subject to monitoring and enforcement by the Federal Trade Commission (FTC), which polices claims by marketers. What constitutes the difference between truthful and false claims is hotly debated and is a central controversy in this arena.

Consumer motivations for using anti-aging products

Research by Sobh and Martin (2011) suggests that people buy anti-aging products to obtain a hoped-for self (e.g., keeping a youthful skin) or to avoid a feared-self (e.g., looking old). The research shows that when consumers pursue a hoped-for self, it is expectations of success that most strongly drive their motivation to use the product. The research also shows why doing badly when trying to avoid a feared self is more motivating than doing well. Interestingly, when product use is seen to fail it is more motivating than success when consumers seek to avoid a feared-self.[32]

Proposed strategies

Caloric restriction

Main article: Calorie restriction

The best-characterized anti-aging therapy was, and still is, CR. In some studies calorie restriction has been shown to extend the life of mice, yeast, and rhesus monkeys significantly.[33][34] However, a more recent study has shown that in contrast, calorie restriction has not improved the survival rate in rhesus monkeys.[35] Long-term human trials of CR are now being done. It is the hope of the anti-aging researchers that resveratrol, found in grapes, or pterostilbene, a more bio-available substance, found in blueberries, as well as rapamycin, a biotic substance discovered on Easter Island, may act as CR mimetics to increase the life span of humans.[36]

More recent work reveals that the effects long attributed to caloric restriction may be obtained by restriction of protein alone, and specifically of just the sulfur-containing amino acids cysteine and methionine.[37][38] Current research is into the metabolic pathways affected by variation in availability of products of these amino acids.

Anti-aging drugs

There are a number of chemicals intended to slow the aging process currently being studied in animal models.[39] One type of research is related to the observed effects a calorie restriction (CR) diet, which has been shown to extend lifespan in some animals[40] Based on that research, there have been attempts to develop drugs that will have the same effect on the aging process as a caloric restriction diet, which are known as Caloric restriction mimetic drugs. Some drugs that are already approved for other uses have been studied for possible longevity effects on laboratory animals because of a possible CR-mimic effect; they include rapamycin,[41] metformin and other geroprotectors.[42] MitoQ, Resveratrol and pterostilbene are dietary supplements that have also been studied in this context.[36][43][44]

Other attempts to create anti-aging drugs have taken different research paths. One notable direction of research has been research into the possibility of using the enzyme telomerase in order to counter the process of telomere shortening.[45] However, there are potential dangers in this, since some research has also linked telomerase to cancer and to tumor growth and formation.[46]

Nanotechnology

Future advances in nanomedicine could give rise to life extension through the repair of many processes thought to be responsible for aging. K. Eric Drexler, one of the founders of nanotechnology, postulated cell repair machines, including ones operating within cells and utilizing as yet hypothetical molecular computers, in his 1986 book Engines of Creation. Raymond Kurzweil, a futurist and transhumanist, stated in his book The Singularity Is Near that he believes that advanced medical nanorobotics could completely remedy the effects of aging by 2030.[47] According to Richard Feynman, it was his former graduate student and collaborator Albert Hibbs who originally suggested to him (circa 1959) the idea of a medical use for Feynman's theoretical micromachines (see nanotechnology). Hibbs suggested that certain repair machines might one day be reduced in size to the point that it would, in theory, be possible to (as Feynman put it) "swallow the doctor". The idea was incorporated into Feynman's 1959 essay There's Plenty of Room at the Bottom.[48]

Cloning and body part replacement

Some life extensionists suggest that therapeutic cloning and stem cell research could one day provide a way to generate cells, body parts, or even entire bodies (generally referred to as reproductive cloning) that would be genetically identical to a prospective patient. Recently, the US Department of Defense initiated a program to research the possibility of growing human body parts on mice.[49] Complex biological structures, such as mammalian joints and limbs, have not yet been replicated. Dog and primate brain transplantation experiments were conducted in the mid-20th century but failed due to rejection and the inability to restore nerve connections. As of 2006, the implantation of bio-engineered bladders grown from patients' own cells has proven to be a viable treatment for bladder disease.[50] Proponents of body part replacement and cloning contend that the required biotechnologies are likely to appear earlier than other life-extension technologies.

The use of human stem cells, particularly embryonic stem cells, is controversial. Opponents' objections generally are based on interpretations of religious teachings or ethical considerations. Proponents of stem cell research point out that cells are routinely formed and destroyed in a variety of contexts. Use of stem cells taken from the umbilical cord or parts of the adult body may not provoke controversy.[51]

The controversies over cloning are similar, except general public opinion in most countries stands in opposition to reproductive cloning. Some proponents of therapeutic cloning predict the production of whole bodies, lacking consciousness, for eventual brain transplantation.

Cyborgs

Replacement of biological (susceptible to diseases) organs with mechanical ones could extend life. This is the goal of 2045 Initiative.[52]

Cryonics

Main article: Cryonics

For cryonicists (advocates of cryopreservation), storing the body at low temperatures after death may provide an "ambulance" into a future in which advanced medical technologies may allow resuscitation and repair. They speculate cryogenic temperatures will minimize changes in biological tissue for many years, giving the medical community ample time to cure all disease, rejuvenate the aged and repair any damage that is caused by the cryopreservation process.

Many cryonicists do not believe that legal death is "real death" because stoppage of heartbeat and breathing—the usual medical criteria for legal death—occur before biological death of cells and tissues of the body. Even at room temperature, cells may take hours to die and days to decompose. Although neurological damage occurs within 4–6 minutes of cardiac arrest, the irreversible neurodegenerative processes do not manifest for hours.[53] Cryonicists state that rapid cooling and cardio-pulmonary support applied immediately after certification of death can preserve cells and tissues for long-term preservation at cryogenic temperatures. People, particularly children, have survived up to an hour without heartbeat after submersion in ice water. In one case, full recovery was reported after 45 minutes underwater.[54] To facilitate rapid preservation of cells and tissue, cryonics "standby teams" are available to wait by the bedside of patients who are to be cryopreserved to apply cooling and cardio-pulmonary support as soon as possible after declaration of death.[55]

No mammal has been successfully cryopreserved and brought back to life, with the exception of frozen human embryos. Resuscitation of a postembryonic human from cryonics is not possible with current science. Some scientists still support the idea based on their expectations of the capabilities of future science.[56][57]

Strategies for Engineered Negligible Senescence (SENS)

Another proposed life extension technology would combine existing and predicted future biochemical and genetic techniques. SENS proposes that rejuvenation may be obtained by removing aging damage via the use of stem cells and tissue engineering, telomere-lengthening machinery, allotopic expression of mitochondrial proteins, targeted ablation of cells, immunotherapeutic clearance, and novel lysosomal hydrolases.[58]

While many biogerontologists find these ideas "worthy of discussion"[59][60] and SENS conferences feature important research in the field,[61][62] some contend that the alleged benefits are too speculative given the current state of technology, referring to it as "fantasy rather than science".[3][5]

Genetic modification

Gene therapy, in which nucleic acid polymers are delivered as a drug and are either expressed as proteins, interfere with the expression of proteins, or correct genetic mutations, has been proposed as a future strategy to prevent aging.[63][64]

A large array of genetic modifications have been found to increase lifespan in model organisms such as yeast, nematode worms, fruit flies, and mice. As of 2013, the longest extension of life caused by a single gene manipulation was roughly 150% in mice and 10-fold in nematode worms.[65]

Fooling genes

In The Selfish Gene, Richard Dawkins describes an approach to life-extension that involves "fooling genes" into thinking the body is young.[66] Dawkins attributes inspiration for this idea to Peter Medawar. The basic idea is that our bodies are composed of genes that activate throughout our lifetimes, some when we are young and others when we are older. Presumably, these genes are activated by environmental factors, and the changes caused by these genes activating can be lethal. It is a statistical certainty that we possess more lethal genes that activate in later life than in early life. Therefore, to extend life, we should be able to prevent these genes from switching on, and we should be able to do so by "identifying changes in the internal chemical environment of a body that take place during aging... and by simulating the superficial chemical properties of a young body".[67]

Reversal of informational entropy

According to some lines of thinking, the ageing process is routed into a basic reduction of biological complexity,[68] and thus loss of information. In order to reverse this loss, gerontologist Marios Kyriazis suggested that it is necessary to increase input of actionable and meaningful information both individually (into individual brains),[69] and collectively (into societal systems).[70] This technique enhances overall biological function through up-regulation of immune, hormonal, antioxidant and other parameters, resulting in improved age-repair mechanisms. Working in parallel with natural evolutionary mechanisms that can facilitate survival through increased fitness, Kryiazis claims that the technique may lead to a reduction of the rate of death as a function of age, i.e. indefinite lifespan.[71]

Mind uploading

Main article: Mind uploading

One hypothetical future strategy that, as some suggest, "eliminates" the complications related to a physical body, involves the copying or transferring (e.g. by progressively replacing neurons with transistors) of a conscious mind from a biological brain to a non-biological computer system or computational device. The basic idea is to scan the structure of a particular brain in detail, and then construct a software model of it that is so faithful to the original that, when run on appropriate hardware, it will behave in essentially the same way as the original brain.[72] Whether or not an exact copy of one's mind constitutes actual life extension is matter of debate.

History of the life extension movement

The extension of life has been a desire of humanity and a mainstay motif in the history of scientific pursuits and ideas throughout history, from the Sumerian Epic of Gilgamesh and the Egyptian Smith medical papyrus, all the way through the Taoists, Ayurveda practitioners, alchemists, hygienists such as Luigi Cornaro, Johann Cohausen and Christoph Wilhelm Hufeland, and philosophers such as Francis Bacon, René Descartes, Benjamin Franklin and Nicolas Condorcet. However, the beginning of the modern period in this endeavor can be traced to the end of the 19th – beginning of the 20th century, to the so-called “fin-de-siècle” (end of the century) period, denoted as an “end of an epoch” and characterized by the rise of scientific optimism and therapeutic activism, entailing the pursuit of life extension (or life-extensionism). Among the foremost researchers of life extension at this period were the Nobel Prize winning biologist Elie Metchnikoff (1845-1916) -- the author of the cell theory of immunity and vice director of Institut Pasteur in Paris, and Charles-Édouard Brown-Séquard (1817-1894) -- the president of the French Biological Society and one of the founders of modern endocrinology.[73]

Sociologist James Hughes claims that science has been tied to a cultural narrative of conquering death since the Age of Enlightenment. He cites Francis Bacon (1561–1626) as an advocate of using science and reason to extend human life, noting Bacon's novel New Atlantis, wherein scientists worked toward delaying aging and prolonging life. Robert Boyle (1627–1691), founding member of the Royal Society, also hoped that science would make substantial progress with life extension, according to Hughes, and proposed such experiments as "to replace the blood of the old with the blood of the young". Biologist Alexis Carrel (1873–1944) was inspired by a belief in indefinite human lifespan that he developed after experimenting with cells, says Hughes.[74]

In 1970, the American Aging Association was formed under the impetus of Denham Harman, originator of the free radical theory of aging. Harman wanted an organization of biogerontologists that was devoted to research and to the sharing of information among scientists interested in extending human lifespan.

In 1976, futurists Joel Kurtzman and Philip Gordon wrote No More Dying. The Conquest Of Aging And The Extension Of Human Life, (ISBN 0-440-36247-4) the first popular book on research to extend human lifespan. Subsequently, Kurtzman was invited to testify before the House Select Committee on Aging, chaired by Claude Pepper of Florida, to discuss the impact of life extension on the Social Security system.

Saul Kent published The Life Extension Revolution (ISBN 0-688-03580-9) in 1980 and created a nutraceutical firm called the Life Extension Foundation, a non-profit organization that promotes dietary supplements. The Life Extension Foundation publishes a periodical called Life Extension Magazine. The 1982 bestselling book Life Extension: A Practical Scientific Approach (ISBN 0-446-51229-X) by Durk Pearson and Sandy Shaw further popularized the phrase "life extension".

In 1983, Roy Walford, a life-extensionist and gerontologist, published a popular book called Maximum Lifespan. In 1988, Walford and his student Richard Weindruch summarized their research into the ability of calorie restriction to extend the lifespan of rodents in The Retardation of Aging and Disease by Dietary Restriction (ISBN 0-398-05496-7). It had been known since the work of Clive McCay in the 1930s that calorie restriction can extend the maximum lifespan of rodents. But it was the work of Walford and Weindruch that gave detailed scientific grounding to that knowledge. Walford's personal interest in life extension motivated his scientific work and he practiced calorie restriction himself. Walford died at the age of 80 from complications caused by amyotrophic lateral sclerosis.

Money generated by the non-profit Life Extension Foundation allowed Saul Kent to finance the Alcor Life Extension Foundation, the world's largest cryonics organization. The cryonics movement had been launched in 1962 by Robert Ettinger's book, The Prospect of Immortality. In the 1960s, Saul Kent had been a co-founder of the Cryonics Society of New York. Alcor gained national prominence when baseball star Ted Williams was cryonically preserved by Alcor in 2002 and a family dispute arose as to whether Williams had really wanted to be cryopreserved.

Regulatory and legal struggles between the Food and Drug Administration (FDA) and the Life Extension Foundation included seizure of merchandise and court action. In 1991, Saul Kent and Bill Faloon, the principals of the Foundation, were jailed. The LEF accused the FDA of perpetrating a "Holocaust" and "seeking gestapo-like power" through its regulation of drugs and marketing claims.[75]

In 2003, Doubleday published "The Immortal Cell: One Scientist's Quest to Solve the Mystery of Human Aging," by Michael D. West. West emphasised the potential role of embryonic stem cells in life extension.[76]

Other modern life extensionists include writer Gennady Stolyarov, who insists that death is "the enemy of us all, to be fought with medicine, science, and technology";[77] transhumanist philosopher Zoltan Istvan, who proposes that the "transhumanist must safeguard one's own existence above all else";[78] futurist George Dvorsky, who considers aging to be a problem that desperately needs to be solved;[79] and recording artist Steve Aoki, who has been called "one of the most prolific campaigners for life extension".[80]

Scientific research

In 1991, the American Academy of Anti-Aging Medicine (A4M) was formed as a non-profit organization to create what it considered an anti-aging medical specialty distinct from geriatrics, and to hold trade shows for physicians interested in anti-aging medicine. The A4M trains doctors in anti-aging medicine and publicly promotes the field of anti-aging research. It has about 26,000 members, of whom about 97% are doctors and scientists.[81] The American Board of Medical Specialties recognizes neither anti-aging medicine nor the A4M's professional standing.[82]

In 2003, Aubrey de Grey and David Gobel formed the Methuselah Foundation, which gives financial grants to anti-aging research projects. In 2009, de Grey and several others founded the SENS Research Foundation, a California-based scientific research organization which conducts research into aging and funds other anti-aging research projects at various universities.[83] In 2013, Google announced Calico, a new company based in San Francisco that will harness new technologies to increase scientific understanding of the biology of aging.[84] It is led by Arthur D. Levinson,[85] and its research team includes scientists such as Hal V. Barron, David Botstein, and Cynthia Kenyon. In 2014, biologist Craig Venter founded Human Longevity Inc., a company dedicated to scientific research to end aging through genomics and cell therapy. They received funding with the goal of compiling a comprehensive human genotype, microbiome, and phenotype database.[86]

Aside from private initiatives, aging research is being conducted in university laboratories, and includes universities such as Harvard and UCLA. University researchers have made a number of breakthroughs in extending the lives of mice and insects by reversing certain aspects of aging.[87][88][89][90]

Ethics and politics of life extension

Political parties

Though many scientists state[91] that life extension and radical life extension are possible, there are still no international or national programs focused on radical life extension. There are political forces staying for and against life extension. By 2012, in Russia, the United States, Israel, and the Netherlands, the Longevity political parties started. They aimed to provide political support to radical life extension research and technologies, and ensure the fastest possible and at the same time soft transition of society to the next step – life without aging and with radical life extension, and to provide access to such technologies to most currently living people.[92]

Commentators

Leon Kass (chairman of the US President's Council on Bioethics from 2001 to 2005) has questioned whether potential exacerbation of overpopulation problems would make life extension unethical.[93] He states his opposition to life extension with the words:

"simply to covet a prolonged life span for ourselves is both a sign and a cause of our failure to open ourselves to procreation and to any higher purpose ... [The] desire to prolong youthfulness is not only a childish desire to eat one's life and keep it; it is also an expression of a childish and narcissistic wish incompatible with devotion to posterity."[94]

John Harris, former editor-in-chief of the Journal of Medical Ethics, argues that as long as life is worth living, according to the person himself, we have a powerful moral imperative to save the life and thus to develop and offer life extension therapies to those who want them.[95]

Transhumanist philosopher Nick Bostrom has argued that any technological advances in life extension must be equitably distributed and not restricted to a privileged few.[96] In an extended metaphor entitled "The Fable of the Dragon-Tyrant", Bostrom envisions death as a monstrous dragon who demands human sacrifices. In the fable, after a lengthy debate between those who believe the dragon is a fact of life and those who believe the dragon can and should be destroyed, the dragon is finally killed. Bostrom argues that political inaction allowed many preventable human deaths to occur.[97]

Overpopulation concerns

Life extension is a controversial topic due to fear of overpopulation and possible effects on society.[98] Biogerontologist Aubrey De Grey counters the overpopulation critique by pointing out that the therapy could postpone or eliminate menopause, allowing women to space out their pregnancies over more years and thus decreasing the yearly population growth rate.[99] Moreover, the philosopher and futurist Max More argues that, given the fact the worldwide population growth rate is slowing down and is projected to eventually stabilize and begin falling, superlongevity would be unlikely to contribute to overpopulation.[98]

Opinion polls

A Spring 2013 Pew Research poll in the United States found that 38% of Americans would want life extension treatments, and 56% would reject it. However, it also found that 68% believed most people would want it and that only 4% consider an "ideal lifespan" to be more than 120 years. The median "ideal lifespan" was 91 years of age and the majority of the public (63%) viewed medical advances aimed at prolonging life as generally good. 41% of Americans believed that radical life extension (RLE) would be good for society, while 51% said they believed it would be bad for society.[100] One possibility for why 56% of Americans claim they would reject life extension treatments may be due to the cultural perception that living longer would result in a longer period of decrepitude, and that the elderly in our current society are unhealthy.[101]

Religious people are no more likely to oppose life extension than the unaffiliated,[100] though some variation exists between religious denominations.

Aging as a disease

Most mainstream medical organizations and practitioners do not consider aging to be a disease. David Sinclair says: "I don't see aging as a disease, but as a collection of quite predictable diseases caused by the deterioration of the body".[102] The two main arguments used are that aging is both inevitable and universal while diseases are not.[103] However, not everyone agrees. Harry R. Moody, Director of Academic Affairs for AARP, notes that what is normal and what is disease strongly depends on a historical context.[104] David Gems, Assistant Director of the Institute of Healthy Ageing, strongly argues that aging should be viewed as a disease.[105] In response to the universality of aging, David Gems notes that it is as misleading as arguing that Basenji are not dogs because they do not bark.[106] Because of the universality of aging he calls it a 'special sort of disease'. Robert M. Perlman, coined the terms ‘aging syndrome’ and ‘disease complex’ in 1954 to describe aging.[107]

The discussion whether aging should be viewed as a disease or not has important implications. It would stimulate pharmaceutical companies to develop life extension therapies and in the United States of America, it would also increase the regulation of the anti-aging market by the FDA. Anti-aging now falls under the regulations for cosmetic medicine which are less tight than those for drugs.[106][108]

See also

References

  1. ↑ "agerasia". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public library membership required.)
  2. 1 2 3 Japsen, Bruce (15 June 2009). "AMA report questions science behind using hormones as anti-aging treatment". The Chicago Tribune. Retrieved 17 July 2009.
  3. 1 2 Holliday, Robin (2008). "The extreme arrogance of anti-aging medicine". Biogerontology. 10 (2): 223–8. doi:10.1007/s10522-008-9170-6. PMID 18726707.
  4. 1 2 Olshansky, S. J.; Hayflick, L; Carnes, B. A. (1 August 2002). "Position statement on human aging". The Journals of Gerontology Series A: Biological Sciences and Medical Sciences. 57 (8): B292–7. doi:10.1093/gerona/57.8.B292. PMID 12145354.
  5. 1 2 "Science fact and the SENS agenda. What can we reasonably expect from ageing research?". EMBO Reports. 6 (11): 1006–8. 2005. doi:10.1038/sj.embor.7400555. PMC 1371037Freely accessible. PMID 16264422.
  6. ↑ Marziali, Carl (7 December 2010). "Reaching Toward the Fountain of Youth". USC Trojan Family Magazine. Retrieved 7 December 2010.
  7. ↑ López-Otín, C; Blasco, M. A.; Partridge, L; Serrano, M; Kroemer, G (2013). "The hallmarks of aging". Cell. 153 (6): 1194–1217. doi:10.1016/j.cell.2013.05.039. PMC 3836174Freely accessible. PMID 23746838.
  8. 1 2 Halliwell B, Gutteridge JMC (2007). Free Radicals in Biology and Medicine. Oxford University Press, USA, ISBN 019856869X, ISBN 978-0198568698
  9. ↑ Holmes, G. E.; Bernstein, C; Bernstein, H (September 1992). "Oxidative and other DNA damages as the basis of aging: a review". Mutation Research/DNAging. 275 (3–6): 305–15. doi:10.1016/0921-8734(92)90034-M. PMID 1383772.
  10. ↑ "Mouse Facts". informatics.jax.org.
  11. ↑ "What Causes Aging? Damage-Based Theories of Aging".
  12. ↑ Verdaguer, E; Junyent, F; Folch, J; Beas-Zarate, C; Auladell, C; Pallàs, M; Camins, A (2012). "Aging biology: a new frontier for drug discovery". Expert Opin Drug Discov. 7 (3): 217–229. doi:10.1517/17460441.2012.660144. PMID 22468953.
  13. ↑ Rauser, C. L.; Mueller, L. D.; Rose, M. R. (2006). "The evolution of late life". Ageing Res Rev. 5 (1): 14–32. doi:10.1016/j.arr.2005.06.003. PMID 16085467.
  14. ↑ Stearns, S. C.; Ackermann, M; Doebeli, M; Kaiser, M (2000). "Experimental evolution of aging, growth, and reproduction in fruitflies". Proceedings of the National Academy of Sciences of the United States of America. 97 (7): 3309–3313. doi:10.1073/pnas.060289597. PMC 16235Freely accessible. PMID 10716732.
  15. ↑ Newmark, P. A.; Sánchez Alvarado, A (2002). "Not your father's planarian: a classic model enters the era of functional genomics". Nat Rev Genet. 3 (3): 210–219. doi:10.1038/nrg759. PMID 11972158.
  16. ↑ Bavestrello, G.; Sommer, C.; Sarà, M. (1992). "Bi-directional conversion in Turritopsis nutricula (Hydrozoa)" (PDF). Scientia Marina. 56 (2–3): 137–140.
  17. ↑ Martínez DE (May 1998). "Mortality patterns suggest lack of senescence in hydra". Experimental Gerontology. 33 (3): 217–25. doi:10.1016/S0531-5565(97)00113-7. PMID 9615920.
  18. ↑ Petralia, Ronald S.; Mattson, Mark P.; Yao, Pamela J. (2014). "Aging and longevity in the simplest animals and the quest for immortality". Ageing Res Rev. 16: 66–82. doi:10.1016/j.arr.2014.05.003. PMC 4133289Freely accessible. PMID 24910306.
  19. ↑ Rando TA; Chang HY (2012). "Aging, rejuvenation, and epigenetic reprogramming: resetting the aging clock". Cell. 148 (1–2): 46–57. doi:10.1016/j.cell.2012.01.003. PMID 22265401.
  20. ↑ Johnson AA, Akman K, Calimport SR, Wuttke D, Stolzing A, de Magalhães JP; Akman; Calimport; Wuttke; Stolzing; De Magalhães (2012). "The role of DNA methylation in aging, rejuvenation, and age-related disease". Rejuvenation Res. 15 (5): 483–494. doi:10.1089/rej.2012.1324. PMC 3482848Freely accessible. PMID 23098078.
  21. 1 2 Shmookler Reis, R. J.; Bharill, P; Tazearslan, C; Ayyadevara, S (2009). "Extreme-longevity mutations orchestrate silencing of multiple signaling pathways". Biochim Biophys Acta. 1790 (10): 1075–83. doi:10.1016/j.bbagen.2009.05.011. PMC 2885961Freely accessible. PMID 19465083.
  22. ↑ Schumacher, B; van der Pluijm, I; Moorhouse, MJ (2008). "Delayed and Accelerated Aging Share Common Longevity Assurance Mechanisms". PLoS Genetics. 4 (8): e1000161. doi:10.1371/journal.pgen.1000161. PMC 2493043Freely accessible. PMID 18704162.
  23. ↑ Chen, J; Velalar, CN; Ruan, R (2008). "Identifying the changes in gene profiles regulating the amelioration of age-related oxidative damages in kidney tissue of rats by the intervention of adult-onset calorie restriction". Rejuvenation Research. 11 (4): 757–63. doi:10.1089/rej.2008.0718. PMID 18710334.
  24. ↑ Holloszy, J. O.; Fontana, L. (2007). "Caloric restriction in humans. Experimental gerontology,". Experimental Gerontology. 42 (8): 707–712. doi:10.1016/j.exger.2007.03.009. PMID 17482403.
  25. ↑ Bjelakovic, Goran; Nikolova, Dimitrinka; Lotte Gluud, Lise; Simonetti Rosa G.; Gluud Christian (2007). "Mortality in Randomized Trials of Antioxidant Supplements for Primary and Secondary Prevention, a Systematic Review and Meta-analysis". JAMA. 297 (8): 842–857. doi:10.1001/jama.297.8.842. PMID 17327526.
  26. ↑ Fernández AF; Fraga MF (Jul 2011). "The effects of the dietary polyphenol resveratrol on human healthy aging and lifespan". Epigenetics. 6 (7): 870–4. doi:10.4161/epi.6.7.16499. PMID 21613817.
  27. 1 2 Mishra, R. N.; Joshi, D. (2011). "Jiao Gu Lan (Gynostemma pentaphyllum): The Chinese Rasayan" (PDF). International Journal of Research in Pharmaceutical and Biomedical Sciences.
  28. ↑ Alexopoulou, O; Abs, R; Maiter, D (2010). "Treatment of adult growth hormone deficiency: who, why and how? A review". Acta Clinica Belgica. 65 (1): 13–22. doi:10.1179/acb.2010.002. PMID 20373593.
  29. ↑ Ahmad, A. M.; Hopkins, M. T.; Thomas, J; Ibrahim, H; Fraser, W. D.; Vora, J. P. (June 2001). "Body composition and quality of life in adults with growth hormone deficiency; effects of low-dose growth hormone replacement". Clinical Endocrinology. 54 (6): 709–17. doi:10.1046/j.1365-2265.2001.01275.x. PMID 11422104.
  30. ↑ Savine R; Sönksen P (2000). "Growth hormone – hormone replacement for the somatopause?". Hormone Research. 53 (Suppl 3): 37–41. doi:10.1159/000023531. PMID 10971102.
  31. ↑ Sattler FR (August 2013). "Growth hormone in the aging male". Best Pract. Res. Clin. Endocrinol. Metab. 27 (4): 541–55. doi:10.1016/j.beem.2013.05.003. PMID 24054930. In animal models, alterations in GH/IGF-1 signaling with reductions in these somatotrophs appear to increase life span.  ... Administration of IGF-1Eb (mechanogrowth factor) stimulates proliferation of myoblasts and induces muscle hypertrophy. Increases in GH and IGF-1 during adolescence are beneficial for brain and cardiovascular function during the aging process and GH administration during adolescence is vasoprotective and increases life-span.15 ... Studies relating GH and IGF-1 status to longevity provide inconsistent evidence as to whether decreased (somatopause) or high levels (e.g. acromegaly) of these hormones are beneficial or detrimental to longevity. ... It is difficult to reconcile the largely protective effects of GH/IGF-1 deficiency on longevity in animals with the inconsistent or deleterious effects of low levels or declining GH/IGF-1 during human aging.
  32. ↑ "Feedback Information and Consumer Motivation. The Moderating Role of Positive and Negative Reference Values in Self-Regulation" (PDF). European Journal of Marketing. 45 (6): 963–986. 2011. doi:10.1108/03090561111119976.
  33. ↑ "Metabolic and behavioral compensations in response to caloric restriction: implications for the maintenance of weight loss". PLOS ONE. 4 (2): e4377. 2009. doi:10.1371/journal.pone.0004377.
  34. ↑ Holloszy JO; Fontana L (2007). "Caloric restriction in humans". Exp Gerontol. 42 (8): 709–12. doi:10.1016/j.exger.2007.03.009. PMID 17482403.
  35. ↑ "Impact of caloric restriction on health and survival in rhesus monkeys from the NIA study". Nature. 489 (7415): 318–321. 2012. doi:10.1038/nature11432. PMC 3832985Freely accessible. PMID 22932268.
  36. 1 2 Kaeberlein, Matt (2010). "Resveratrol,pterostilbene and rapamycin:are they anti-aging drugs?". BioEssays. 32 (2): 96–99. doi:10.1002/bies.200900171. PMID 20091754.
  37. ↑ "Altered dietary methionine differentially impacts glutathione and methionine metabolism in long-living growth hormone-deficient Ames dwarf and wild-type mice". Longevity & Healthspan. 3 (10). 2014. doi:10.1186/2046-2395-3-10.
  38. ↑ "Sparing of methionine requirements: evaluation of human data takes sulfur amino acids beyond protein". J Nutr. 136 (6 Suppl): 1676S–1681S. 2006.
  39. ↑ Childs et al. (2015). Cellular senescence in aging and age-related disease: from mechanisms to therapy Nature Medicine {{doi:10.1038/nm.4000}}
  40. ↑ Anderson, M.; Shanmuganayagam, D.; Weindruch, R. (2009). "Caloric restriction and aging: studies in mice and monkeys". Toxicologic pathology. 37 (1): 47–51. doi:10.1177/0192623308329476. PMID 19075044.
  41. ↑ "Rapamycin fed late in life extends lifespan in genetically heterogeneous mice". Nature. 460: 392–5. 2009. doi:10.1038/nature08221. PMC 2786175Freely accessible. PMID 19587680.
  42. ↑ "Identification of Potential Caloric Restriction Mimetics by Microarray Profiling". Physiological Genomics. 23 (3): 343–50. 2005. doi:10.1152/physiolgenomics.00069.2005. PMID 16189280.
  43. ↑ "A Low Dose of Dietary Resveratrol Partially Mimics Caloric Restriction and Retards Aging Parameters in Mice". PLOS ONE. 3 (6): e2264. doi:10.1371/journal.pone.0002264. PMC 2386967Freely accessible. PMID 18523577.
  44. ↑ McCormack D, McFadden D. A review of pterostilbene antioxidant activity and disease modification. Oxid Med Cell Longev. 2013;2013:575482. PMID 23691264 PMC 3649683
  45. ↑ "Telomeres and Telomerase Basic Science Implications for Aging". American Geriatrics Society. 49 (8): 1105–1109. doi:10.1046/j.1532-5415.2001.49217.x.
  46. ↑ Blackburn, E. H. (2005). "Telomerase and Cancer: Kirk A. Landon - AACR Prize for Basic Cancer Research Lecture". Molecular Cancer Research. 3 (9): 477–82. doi:10.1158/1541-7786.MCR-05-0147. PMID 16179494.
  47. ↑ Kurzweil, Ray (2005). The Singularity Is Near. New York City: Viking Press. ISBN 978-0-670-03384-3. OCLC 57201348.
  48. ↑ Richard P. Feynman (December 1959). "There's Plenty of Room at the Bottom". Retrieved March 2010. Check date values in: |access-date= (help)
  49. ↑ Melanson, Donald (April 22, 2008). "DoD establishes institute tasked with regrowing body parts". Engadget. Retrieved June 29, 2010.
  50. ↑ Khamsi, Roxanne (April 4, 2006). "Bio-engineered bladders successful in patients". New Scientist. Retrieved January 26, 2011.
  51. ↑ White, Christine (19 August 2005). "Umbilical stem cell breakthrough". The Australian. Retrieved 17 July 2009.
  52. ↑ David Segal for the New York Times. 1 June 2013 This Man Is Not a Cyborg. Yet.
  53. ↑ "Neuronal necrosis after middle cerebral artery occlusion in Wistar rats progresses at different time intervals in the caudoputamen and the cortex". Stroke. 26 (4): 636–42; discussion 643. 1995. doi:10.1161/01.STR.26.4.636. PMID 7709411.
  54. ↑ "Full recovery after 45 min accidental submersion". Intensive Care Medicine. 28 (4): 524. April 2002. doi:10.1007/s00134-002-1245-2. PMID 11967613.
  55. ↑ "Comprehensive Member Standby". Retrieved 14 December 2010.
  56. ↑ "Scientists' Open Letter on Cryonics". Retrieved 17 July 2009.
  57. ↑ "Advances in Cryonics". Retrieved 14 December 2010.
  58. ↑ de Grey, Aubrey; Michael Rae (2007). Ending Aging: The Rejuvenation Breakthroughs that Could Reverse Human Aging in Our Lifetime. New York City: St. Martin's Press. ISBN 978-0-312-36706-0. OCLC 132583222.
  59. ↑ Pontin, Jason (July 11, 2006). "Is Defeating Aging Only A Dream?". Technology Review.
  60. ↑ Garreau, Joel (October 31, 2007). "Invincible Man". Washington Post.
  61. ↑ Fourth SENS Conference (2009). Over 140 Accepted Abstracts. Cambridge, England, September 3–7th, 2009.
  62. ↑ Kristen Fortney (2009). SENS4 Conference Coverage From Ouroboros. FightAging.org, September 4, 2009.
  63. ↑ Goya, Rodolfo G.; Federico Bolognani; Claudia B. Hereñú; Omar J. Rimoldi (2001-01-08). "Neuroendocrinology of Aging: The Potential of Gene Therapy as an Interventive Strategy". Gerontology. 47 (168–173): 168–173. doi:10.1159/000052792.
  64. ↑ Rattan, S. I. S.; Singh, R. (2008-10-22). "Progress & Prospects: Gene therapy in aging". Gene Therapy. 16 (3–9): 3–9. doi:10.1038/gt.2008.166. PMID 19005494.
  65. ↑ Tacutu, R.; Craig, T.; Budovsky, A.; Wuttke, D.; Lehmann, G.; Taranukha, D.; Costa, J.; Fraifeld, V. E.; De Magalhaes, J. P. (2012). "Human Ageing Genomic Resources: Integrated databases and tools for the biology and genetics of ageing". Nucleic Acids Research. 41 (Database issue): D1027–33. doi:10.1093/nar/gks1155. PMC 3531213Freely accessible. PMID 23193293.
  66. ↑ Dawkins, Richard (2006) [1976]. The Selfish Gene. New York: Oxford University Press. pp. 41–42. ISBN 978-0-19-929115-1.
  67. ↑ Dawkins, Richard (2006) [1976]. The Selfish Gene. New York: Oxford University Press. p. 42. ISBN 978-0-19-929115-1.
  68. ↑ Lipsitz, L. A. (2006). "Aging as a Process of Complexity Loss". Complex Systems Science in Biomedicine. Topics in Biomedical Engineering International Book Series. p. 641. doi:10.1007/978-0-387-33532-2_28. ISBN 978-0-387-30241-6.
  69. ↑ "h+ Magazine – The Longevity of Real Human Avatars – h+ Magazine". h+ Magazine.
  70. ↑ Kyriazis, Marios (October 30, 2012). "The Myth of the Longevity Elixir". ieet.org.
  71. ↑ Kryiazis, Marios (December 2, 2012) The Global Brain and its Role in Human Immortality. immortallife.info
  72. ↑ Sandberg, Anders; Boström, Nick (2008). Whole Brain Emulation: A Roadmap (PDF). Technical Report #2008‐3. Future of Humanity Institute, Oxford University. Retrieved 7 March 2013. The basic idea is to take a particular brain, scan its structure in detail, and construct a software model of it that is so faithful to the original that, when run on appropriate hardware, it will behave in essentially the same way as the original brain.
  73. ↑ Stambler, Ilia (2014). A History of Life-Extensionism in the Twentieth Century. Longevity History. ISBN 1500818577.
  74. ↑ Hughes, James (October 20, 2011). "Transhumanism". In Bainbridge, William. Leadership in Science and Technology: A Reference Handbook. Sage Publications. p. 587. ISBN 1452266522.
  75. ↑ Clevenger, Ty (Summer 2000). "Internet pharmacies: cyberspace versus the regulatory state". Journal of Law and Health. Retrieved 17 July 2009.
  76. ↑ West, Michael D. (2003). The Immortal Cell: One Scientist's Quest to Solve the Mystery of Human Aging. Doubleday. ISBN 978-0-385-50928-2.
  77. ↑ Stolyarov, Gennady (November 25, 2013). Death is Wrong (PDF). Rational Argumentator Press. ISBN 978-0615932040.
  78. ↑ Istvan, Zoltan (October 2, 2014). "The Morality of Artificial Intelligence and the Three Laws of Transhumanism". Huffington Post.
  79. ↑ "Futurist: 'I will reap benefits of life extension'". Al Jazeera America. May 7, 2015. To Dvorsky, aging is a problem that’s desperately in need of solving.
  80. ↑ Tez, Riva Melissa (May 11, 2015). "Steve Aoki, Dan Bilzerian, a giraffe and the search for eternal life". i-D. VICE. Unknown to most, Steve is both an undeniable champion of life expansion as well as one of the most prolific campaigners for life extension. Understanding that the depth of his life's experience is limited by time alone, in his latest album Neon Future he pens lyrics such as 'Life has limitless variety... But today, because of ageing, it does not have limitless scope.' [...] Set up by the Steve Aoki Charitable Fund, the profits from the Dan Bilzerian party went to life extension research.
  81. ↑ "About the A4M". Worldhealth.net.
  82. ↑ Kuczynski, Alex (12 April 1998). "Anti-Aging Potion Or Poison?". The New York Times. Retrieved 17 July 2009.
  83. ↑ research report 2011. Sens Foundation
  84. ↑ Arion McNicoll, Arion (3 October 2013). "How Google's Calico aims to fight aging and 'solve death'". CNN.
  85. ↑ "Google announces Calico, a new company focused on health and well-being". Google. September 18, 2013.
  86. ↑ Human Longevity Inc. (4 March 2014). "Human Longevity Inc. (HLI) Launched to Promote Healthy Aging Using Advances in... – SAN DIEGO, March 4, 2014 /PRNewswire/ --".
  87. ↑ Landau, Elizabeth (5 May 2014). "Young blood makes old mice more youthful". CNN.
  88. ↑ "Harvard researchers find protein that could reverse the aging process". gizmag.com.
  89. ↑ Wolpert, Stuart. "UCLA biologists delay the aging process by 'remote control'". UCLA.edu.
  90. ↑ "Australian and US scientists reverse ageing in mice, humans could be next". ABC News.
  91. ↑ "Scientists' Open Letter on Aging". Imminst.org. Retrieved 2012-10-07.
  92. ↑ "A Single-Issue Political Party for Longevity Science". Fightaging.org. Retrieved 2012-10-07.
  93. ↑ Smith, Simon (3 December 2002). "Killing Immortality". Betterhumans. Archived from the original on 7 June 2004. Retrieved 17 July 2009.
  94. ↑ Kass, Leon (1985). Toward a more natural science: biology and human affairs. New York City: Free Press. p. 316. ISBN 978-0-02-918340-3. OCLC 11677465.
  95. ↑ Harris J. (2007) Enhancing Evolution: The ethical case for making better people. Princeton University Press, New Jersey.
  96. ↑ Sutherland, John (9 May 2006). "The ideas interview: Nick Bostrom". The Guardian. London. Retrieved 17 July 2009.
  97. ↑ Bostrom, N (May 2005). "The fable of the dragon tyrant". Journal of Medical Ethics. 31 (5): 273–7. doi:10.1136/jme.2004.009035. PMC 1734155Freely accessible. PMID 15863685.
  98. 1 2 "Superlongevity Without Overpopulation". Fight Aging!.
  99. ↑ "Peter Singer on Should We Live to 1,000? – Project Syndicate". Project Syndicate.
  100. 1 2 "Living to 120 and Beyond: Americans' Views on Aging, Medical Advances and Radical Life Extension". Pew Research Center's Religion & Public Life Project. 6 August 2013.
  101. ↑ de Magalhães JP (2014). "The scientific quest for lasting youth: prospects for curing aging". Rejuvenation Res. 17 (5): 458–67. doi:10.1089/rej.2014.1580. PMC 4203147Freely accessible. PMID 25132068.
  102. ↑ Hayden EC (2007). "A new angle on 'old'". Nature. 450 (7170): 603–603. doi:10.1038/450603a. PMID 18046373.
  103. ↑ Hamerman D. (2007) Geriatric Bioscience: The link between aging & disease. The Johns Hopkins University Press, Maryland.
  104. ↑ Moody HR (2002). "Who's afraid of life extension?". Generations. 25 (4): 33–7.
  105. ↑ Gems D (2011). "Aging: To Treat, or Not to Treat? The possibility of treating aging is not just an idle fantasy". American Scientist. 99 (4): 278–80. doi:10.1511/2011.91.278.
  106. 1 2 Gems D (2011). "Tragedy and delight: the ethics of decelerated ageing". Phil Trans R Soc B. 366 (1561): 108–112. doi:10.1098/rstb.2010.0288.
  107. ↑ Perlman RM (1954). "The aging syndrome". J Am Geriatr Soc. 2: 123–129.
  108. ↑ Mehlman, M. J.; Binstock, R. H.; Juengst, E. T.; Ponsaran, R. S.; Whitehouse, P. J. (2004). "Anti-aging medicine: Can consumers be better protected?". The Gerontologist. 44 (3): 304–10. doi:10.1093/geront/44.3.304. PMID 15197284.

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