Rejuvenation is a medical discipline focused on the practical reversal of the aging process .
126-484: Rejuvenation is distinct from life extension . Life extension strategies often study the causes of aging and try to oppose those causes in order to slow aging. Rejuvenation is the reversal of aging and thus requires a different strategy, namely repair of the damage that is associated with aging or replacement of damaged tissue with new tissue. Rejuvenation can be a means of life extension, but most life extension strategies do not involve rejuvenation. Various myths tell
252-655: A Yale School of Public Health study. In a UNFPA report about ageing in the 21st century, it highlighted the need to "Develop a new rights-based culture of ageing and a change of mindset and societal attitudes towards ageing and older persons, from welfare recipients to active, contributing members of society". UNFPA said that this "requires, among others, working towards the development of international human rights instruments and their translation into national laws and regulations and affirmative measures that challenge age discrimination and recognise older people as autonomous subjects". Older people's music participation contributes to
378-596: 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. CRISPR/Cas9 edits genes by precisely cutting DNA and then harnessing natural DNA repair processes to modify the gene in the desired manner. The system has two components: the Cas9 enzyme and a guide RNA. 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,
504-511: 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. 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 nanomachines (see biological machine ). Hibbs suggested that certain repair machines might one day be reduced in size to
630-439: A limb , but can regenerate the lens or retina of an eye and can regenerate an intestine . For regeneration the salamander tissues form a blastema by de-differentiation of mesenchymal cells , and the blastema functions as a self-organizing system to regenerate the limb. Yet another option involves cosmetic changes to the individual to create the appearance of youth. These are generally superficial and do little to make
756-449: A biological timetable that might be a continuation of inherent mechanisms that regulate childhood growth and development. This regulation would depend on changes in gene expression that affect the systems responsible for maintenance, repair and defense responses. Factors causing errors or damage include internal and environmental events that induce cumulative deterioration in one or more organs . One 2013 review assessed ageing through
882-559: A broader sense, ageing can refer to single cells within an organism which have ceased dividing , or to the population of a species . In humans, ageing represents the accumulation of changes in a human being over time and can encompass physical, psychological, and social changes. Reaction time, for example, may slow with age, while memories and general knowledge typically increase. Ageing is associated with increased risk of cancer, Alzheimer's disease , diabetes , cardiovascular disease , increased mental health risks, and many more . Of
1008-520: A collection of quite predictable diseases caused by the deterioration of the body." The two main arguments used are that aging is both inevitable and universal while diseases are not. However, not everyone agrees. Harry R. Moody, director of academic affairs for AARP , notes that what is normal and what is disease strongly depend on a historical context. David Gems , assistant director of the Institute of Healthy Ageing, argues that aging should be viewed as
1134-427: A combination of genetic engineering and caloric restriction . 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
1260-478: A common transition faced by the elderly, may have both positive and negative consequences. As cyborgs currently are on the rise some theorists argue there is a need to develop new definitions of ageing and for instance a bio-techno-social definition of ageing has been suggested. There is a current debate as to whether or not the pursuit of longevity and the postponement of senescence are cost-effective health care goals given finite health care resources. Because of
1386-679: 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,
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#17328760680051512-540: A disease. 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. 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. The discussion whether aging should be viewed as a disease or not has important implications. One view is, this would stimulate pharmaceutical companies to develop life extension therapies and in
1638-693: A feared-self. Though many scientists state 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 working both 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
1764-494: A healthy youthful condition (agerasia ). The ethical ramifications, if life extension becomes a possibility, are debated by bioethicists . The sale of purported anti-aging products such as supplements and hormone replacement is a lucrative global industry. For example, the industry that promotes the use of hormones as a treatment for consumers to slow or reverse the aging process in the US market generated about $ 50 billion of revenue
1890-459: 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. When product use is seen to fail it is more motivating than success when consumers seek to avoid
2016-408: A human corpse, with the hope that resuscitation may be possible in the future . It is regarded with skepticism within the mainstream scientific community and has been characterized as quackery . Another proposed life extension technology aims to combine existing and predicted future biochemical and genetic techniques. SENS proposes that rejuvenation may be obtained by removing aging damage via
2142-407: A large extent, is genetically based. For example, numerous perennial plants ranging from strawberries and potatoes to willow trees typically produce clones of themselves by vegetative reproduction and are thus potentially immortal, while annual plants such as wheat and watermelons die each year and reproduce by sexual reproduction. In 2008 it was discovered that inactivation of only two genes in
2268-415: A longer period of decrepitude, and that the elderly in our current society are unhealthy. Religious people are no more likely to oppose life extension than the unaffiliated, though some variation exists between religious denominations. Most mainstream medical organizations and practitioners do not consider aging to be a disease. Biologist David Sinclair says: "I don't see aging as a disease, but as
2394-450: A low level, and regulatory standards are high. Aging is not recognized as a preventable condition by governments, indicating there is no clear pathway to approval of anti-aging medications. Further, anti-aging drug candidates are under constant review by regulatory authorities like the US Food and Drug Administration , which stated in 2023 that "no medication has been proven to slow or reverse
2520-409: A lower mortality rate compared to individuals who are not physically active. The majority of the benefits from exercise are achieved with around 3500 metabolic equivalent (MET) minutes per week. For example, climbing stairs 10 minutes, vacuuming 15 minutes, gardening 20 minutes, running 20 minutes, and walking or bicycling for 25 minutes on a daily basis would together achieve about 3000 MET minutes
2646-505: A myth among modern Chinese that Japan was founded by these people. In some religions, people were to be rejuvenated after death prior to placing them in heaven . The stories continued well into the 16th century. The Spanish explorer Juan Ponce de León led an expedition around the Caribbean islands and into Florida to find the Fountain of Youth . Led by the rumors, the expedition continued
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#17328760680052772-457: A new tissue or animal without ageing. Normal human cells however die after about 50 cell divisions in laboratory culture (the Hayflick Limit , discovered by Leonard Hayflick in 1961). A number of characteristic ageing symptoms are experienced by a majority, or by a significant proportion of humans during their lifetimes. Dementia becomes more common with age. About 3% of people between
2898-490: A novel aging route with substantially extended lifespan. In The Selfish Gene , Richard Dawkins describes an approach to life-extension that involves "fooling genes" into thinking the body is young. 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
3024-438: A number of mental health issues as older adults deal with challenges such as the death of loved ones, retirement and loss of purpose, as well as their own health issues. Some warning signs are: changes in mood or energy, changes in sleep or eating habits, pain, sadness, unhealthy coping mechanisms such as smoking, suicidal ideations, and others. [1] Older adults are more prone to social isolation as well, which can further increase
3150-498: 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 life expectancy and lifespan can often be achieved by access to improved medical care, vaccinations , good diet , exercise , and avoidance of hazards such as smoking . Maximum lifespan
3276-526: A privileged few. 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. Controversy about life extension
3402-515: A problem that desperately needs to be solved; and recording artist Steve Aoki , who has been called "one of the most prolific campaigners for life extension". In 1991, the American Academy of Anti-Aging Medicine (A4M) was formed. The American Board of Medical Specialties recognizes neither anti-aging medicine nor the A4M's professional standing. In 2003, Aubrey de Grey and David Gobel formed
3528-474: A project, strategies for engineered negligible senescence (SENS), to study how to reverse the damage caused by aging. He has proposed seven strategies for what he calls the seven deadly sins of aging: In 2009, Aubrey de Grey co-founded the SENS Foundation to expedite progress in the above-listed areas. Life extension Chemical Neurological Life extension is the concept of extending
3654-484: A promising candidate for further research within the field. Their study suggests that high levels of iron in the blood likely reduce, and genes involved in metabolising iron likely increase healthy years of life in humans. The same month other scientists report that yeast cells of the same genetic material and within the same environment age in two distinct ways, describe a biomolecular mechanism that can determine which process dominates during aging and genetically engineer
3780-495: A safety net that contributes to the postponement of disability and prevention of impoverishment in old age". It has been argued that population ageing has undermined economic development and can lead to lower inflation because elderly individuals care especially strongly about the value of their pensions and savings. Evidence suggests that pensions, while making a difference to the well-being of older persons, also benefit entire families especially in times of crisis when there may be
3906-485: A shortage or loss of employment within households. A study by the Australian Government in 2003 estimated that "women between the ages of 65 and 74 years contribute A$ 16 billion per year in unpaid caregiving and voluntary work. Similarly, men in the same age group contributed A$ 10 billion per year." Due to increasing share of the elderly in the population, health care expenditures will continue to grow relative to
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4032-430: A specific age for when an individual is allowed or obliged to do particular activities. These age specifications include voting age , drinking age , age of consent , age of majority , age of criminal responsibility , marriageable age , age of candidacy , and mandatory retirement age . Admission to a movie, for instance, may depend on age according to a motion picture rating system . A bus fare might be discounted for
4158-499: A stochastic data-based clock. Most attempts at genetic repair have traditionally involved the use of a retrovirus to insert a new gene into a random position on a chromosome . But by attaching zinc fingers (which determine where transcription factors bind) to endonucleases (which break DNA strands), homologous recombination can be induced to correct and replace defective (or undesired) DNA sequences. The first applications of this technology are to isolate stem cells from
4284-430: A variety of contexts. Use of stem cells taken from the umbilical cord or parts of the adult body may not provoke controversy. 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. Some critics dispute
4410-491: A viable treatment for bladder disease. 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
4536-469: A week. Exercise has also been found to be an effective measure to treat declines in neuromuscular function due to age. A meta-analysis found that resistance training with elastic bands or kettlebells provided significant improvements to grip strength, gait speed, and skeletal muscle mass in patients with sarcopenia . Furthermore, another analysis found that the positive effects of resistance exercise on strength, muscle mass, and motor coordination reduce
4662-589: A year in 2009. The use of such hormone products has not been proven to be effective or safe. 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." Oxidation damage to cellular contents caused by free radicals
4788-403: Is selected for in evolution. Traits that benefit early survival and reproduction will be selected for even if they contribute to an earlier death. Such a genetic effect is called the antagonistic pleiotropy effect when referring to a gene (pleiotropy signifying the gene has a double function – enabling reproduction at a young age but costing the organism life expectancy in old age) and is called
4914-481: Is also evidence to suggest that exercise of any type may mitigate the degradation of the neuromuscular junction (NMJ) that occurs with age. Current evidence suggests that aerobic exercise causes the most hypertrophy of the NMJ, although resistance training is still somewhat effective. However, further evidence is necessary to identify optimal training protocols for NMJ function and to further understand how exercise affects
5040-459: Is another common visual disease that appears in older adults. Glaucoma is caused by damage to the optic nerve, causing vision loss. Glaucoma usually develops over time, but there are variations to glaucoma, and some have a sudden onset. There are a few procedures for glaucoma, but there is no cure or fix for the damage, once it has occurred. Prevention is the best measure in the case of glaucoma. In addition to physical symptoms, aging can also cause
5166-520: 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. 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
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5292-617: Is believed to contribute to aging as well. The longest documented human lifespan is 122 years 164 days, the case of Jeanne Calment , who according to records 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. 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 . The average life expectancy in
5418-472: Is credited with lowering the risk of heart disease and early death. The major contributors to mortality risk reduction appear to be a higher consumption of vegetables, fish, fruits, nuts and monounsaturated fatty acids, such as by consuming olive oil. As of 2021, there is insufficient clinical evidence that calorie restriction or any dietary practice affects the process of ageing. People who participate in moderate to high levels of physical exercise have
5544-641: 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. Another technique uses evolutionary pressures such as breeding from only older members or altering levels of extrinsic mortality. Some animals such as hydra , planarian flatworms , and certain sponges , corals , and jellyfish do not die of old age and exhibit potential immortality. The extension of life has been
5670-407: Is due to fear of overpopulation and possible effects on society. 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. Moreover, the philosopher and futurist Max More argues that, given that
5796-577: Is mediated by systemic environment, rather than being an intrinsic cell property. Clinical trials based on transfusion of young blood were scheduled to begin in 2014. Another intervention that is gaining popularity is epigenetic reprogramming. Through the use of Yamanaka factors , aged cells can revert to a younger state. It has been demonstrated that reprogramming induces a youthful epigenetic state and can restore vision after injury. Only through reprogramming were stochastic epigenetic variations, which accumulate with age, successfully reversed, as demonstrated by
5922-491: Is not mainly due to increasing demand from ageing populations, but rather has been driven by rising incomes, costly new medical technology, a shortage of health care workers and informational asymmetries between providers and patients. A number of health problems become more prevalent as people get older. These include mental health problems as well as physical health problems, especially dementia . It has been estimated that population ageing only explains 0.2 percentage points of
6048-658: 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." 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. Transhumanist philosopher Nick Bostrom has argued that any technological advances in life extension must be equitably distributed and not restricted to
6174-455: 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,
6300-562: Is of particular concern, particularly in developed countries, while social protection and old-age pension coverage remain a challenge for developing countries, where a large proportion of the labour force is found in the informal sector." The global economic crisis has increased financial pressure to ensure economic security and access to health care in old age. To elevate this pressure "social protection floors must be implemented in order to guarantee income security and access to essential health and social services for all older persons and provide
6426-446: Is over 80 now in 33 countries. Ageing is a "global phenomenon", that is occurring fastest in developing countries, including those with large youth populations, and poses social and economic challenges to the work which can be overcome with "the right set of policies to equip individuals, families and societies to address these challenges and to reap its benefits". As life expectancy rises and birth rates decline in developed countries,
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#17328760680056552-693: Is the accumulation of damage to macromolecules , cells , tissues and organs in and on the body which, when it can no longer be tolerated by an organism , ultimately leads to its death . If any of that damage can be repaired, the result is rejuvenation. There have been many experiments which have been shown to increase the maximum life span of laboratory animals, thereby achieving life extension . A few experimental methods such as replacing hormones to youthful levels have had considerable success in partially rejuvenating laboratory animals and humans. A 2011 experiment involved breeding genetically manipulated mice that lacked an enzyme called telomerase, causing
6678-625: Is the increase in the number and proportion of older people in society. Population ageing has three possible causes: migration, longer life expectancy (decreased death rate) and decreased birth rate. Ageing has a significant impact on society. Young people tend to have fewer legal privileges (if they are below the age of majority ), they are more likely to push for political and social change, to develop and adopt new technologies, and to need education. Older people have different requirements from society and government, and frequently have differing values as well, such as for property and pension rights. In
6804-451: Is to discover or develop agents to delay, prevent, alleviate, or reverse age-related diseases. Removal of senescent cells with senolytics has been proposed as a method of enhancing immunity during aging. Senolytics eliminate senescent cells whereas senomorphics – with candidates such as Apigenin , Everolimus and Rapamycin – modulate properties of senescent cells without eliminating them, suppressing phenotypes of senescence, including
6930-548: 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
7056-659: 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. In 2013, Google announced Calico , a new company based in San Francisco that will harness new technologies to increase scientific understanding of
7182-650: The SASP . Senomorphic effects may be one major effect mechanism of a range of prolongevity drug candidates. Such candidates are however typically not studied for just one mechanism, but multiple. There are biological databases of prolongevity drug candidates under research as well as of potential gene/protein targets. These are enhanced by longitudinal cohort studies , electronic health records , computational (drug) screening methods, computational biomarker-discovery methods and computational biodata-interpretation/ personalized medicine methods. Besides rapamycin and senolytics,
7308-513: The bone marrow of patients having blood disease mutations , to correct those mutations in laboratory dishes using zinc finger endonucleases and to transplant the stem cells back into the patients. More recent efforts leverage CRISPR-Cas systems or adeno-associated viruses (AAVs). Enhanced DNA repair has been proposed as a potential rejuvenation strategy. See DNA damage theory of aging . Stem cell regenerative medicine uses three different strategies: A salamander can not only regenerate
7434-480: The disposable soma effect when referring to an entire genetic programme (the organism diverting limited resources from maintenance to reproduction). The biological mechanisms which regulate lifespan probably evolved with the first multicellular organisms more than a billion years ago. However, even single-celled organisms such as yeast have been used as models in ageing, hence ageing has its biological roots much earlier than multi-cellularity. The Mediterranean diet
7560-473: The drug-repurposing candidates studied most extensively include metformin , acarbose , spermidine and NAD+ enhancers. Aging Ageing (or aging in American English ) is the process of becoming older . The term refers mainly to humans , many other animals , and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal . In
7686-533: The hard clam (known as quahog in New England) at 508 years, the Greenland shark at 400 years, various deep-sea tube worms at over 300 years, fish like the sturgeon and the rockfish , and the sea anemone and lobster . Such organisms are sometimes said to exhibit negligible senescence . The genetic aspect has also been demonstrated in studies of human centenarians . Life span, like other phenotypes ,
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#17328760680057812-481: The median age rises accordingly. According to the United Nations, this process is taking place in nearly every country in the world. A rising median age can have significant social and economic implications, as the workforce gets progressively older and the number of old workers and retirees grows relative to the number of young workers. Older people generally incur more health-related costs than do younger people in
7938-594: The 21st century, one of the most significant population trends is ageing. Currently, over 11% of the world's current population are people aged 60 and older and the United Nations Population Fund (UNFPA) estimates that by 2050 that number will rise to approximately 22%. Ageing has occurred due to development which has enabled better nutrition, sanitation, health care, education and economic well-being. Consequently, fertility rates have continued to decline and life expectancy has risen. Life expectancy at birth
8064-588: 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. Sociologist James Hughes claims that science has been tied to a cultural narrative of conquering death since
8190-484: The US President's Council on Bioethics from 2001 to 2005) has questioned whether potential exacerbation of overpopulation problems would make life extension unethical. 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
8316-555: The United States of America, it would also increase the regulation of the anti-aging market by the Food and Drug Administration (FDA). Anti-aging now falls under the regulations for cosmetic medicine which are less tight than those for drugs. A senolytic (from the words senescence and -lytic , "destroying") is among a class of small molecules under basic research to determine if they can selectively induce death of senescent cells and improve health in humans. A goal of this research
8442-479: The accumulated infirmities of old age, bioethicist Ezekiel Emanuel , opines that the pursuit of longevity via the compression of morbidity hypothesis is a "fantasy" and that human life is not worth living after age 75; longevity then should not be a goal of health care policy. This opinion has been contested by neurosurgeon and medical ethicist Miguel Faria , who states that life can be worthwhile during old age, and that longevity should be pursued in association with
8568-490: The age of 80. This degeneration is caused by systemic changes in the circulation of waste products and by the growth of abnormal vessels around the retina. Other visual diseases that often appear with age are cataracts and glaucoma. A cataract occurs when the lens of the eye becomes cloudy, making vision blurry; it eventually causes blindness if untreated. They develop over time and are seen most often with those that are older. Cataracts can be treated through surgery. Glaucoma
8694-567: The ages of 65 and 74, 19% of those between 75 and 84, and nearly half of those over 85 years old have dementia. The spectrum ranges from mild cognitive impairment to the neurodegenerative diseases of Alzheimer's disease , cerebrovascular disease , Parkinson's disease and Lou Gehrig's disease . Furthermore, many types of memory decline with ageing , but not semantic memory or general knowledge such as vocabulary definitions. These typically increase or remain steady until late adulthood (see Ageing brain ). Intelligence declines with age, though
8820-416: The aging process." 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 ,
8946-456: The annual growth rate in medical spending of 4.3% since 1970. In addition, certain reforms to the Medicare system in the United States decreased elderly spending on home health care by 12.5% per year between 1996 and 2000. Beauty standards have evolved over time, and as scientific research in cosmeceuticals, cosmetic products seen to have medicinal benefits like anti-ageing creams, has increased,
9072-431: The annual plant Arabidopsis thaliana leads to its conversion into a potentially immortal perennial plant. The oldest animals known so far are 15,000-year-old Antarctic sponges , which can reproduce both sexually and clonally. Clonal immortality apart, there are certain species whose individual lifespans stand out among Earth's life-forms, including the bristlecone pine at 5062 years or 5067 years, invertebrates like
9198-433: The attainment of quality of life. Faria claims that postponement of senescence as well as happiness and wisdom can be attained in old age in a large proportion of those who lead healthy lifestyles and remain intellectually active. With age inevitable biological changes occur that increase the risk of illness and disability. UNFPA states that: "A life-cycle approach to health care – one that starts early, continues through
9324-587: The bacterium E. coli may split into distinguishable daughter cells, which opens the theoretical possibility of "age classes" among bacteria. Even within humans and other mortal species, there are cells with the potential for immortality: cancer cells which have lost the ability to die when maintained in a cell culture such as the HeLa cell line, and specific stem cells such as germ cells (producing ova and spermatozoa ). In artificial cloning , adult cells can be rejuvenated to embryonic status and then used to grow
9450-429: 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
9576-487: The biology of aging. It is led by Arthur D. Levinson , 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. Aside from private initiatives, aging research
9702-520: 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. Regulatory and legal struggles between the Food and Drug Administration (FDA) and the Life Extension organization included seizure of merchandise and court action. In 1991, Saul Kent and Bill Faloon ,
9828-543: The body will respond to them as it did when it was younger, thus repairing and restoring many body functions. In line with this, recent experiments show that heterochronic parabiosis , i.e. connecting the circulatory systems of young and old animal, leads to the rejuvenation of the old animal, including restoration of proper stem cell function. Similar experiments show that grafting old muscles into young hosts leads to their complete restoration, whereas grafting young muscles into old hosts does not. These experiments show that aging
9954-410: 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
10080-695: The economy in coming decades. This has been considered as a negative phenomenon and effective strategies like labour productivity enhancement should be considered to deal with negative consequences of ageing. In the field of sociology and mental health, ageing is seen in five different views: ageing as maturity , ageing as decline, ageing as a life-cycle event, ageing as generation, and ageing as survival. Positive correlates with ageing often include economics, employment, marriage, children, education, and sense of control, as well as many others. The social science of ageing includes disengagement theory, activity theory, selectivity theory, and continuity theory. Retirement,
10206-417: The emergence of the fungal/animal kingdoms approximately a billion years ago, and the evolution of seed-producing plants 320 million years ago. The sexual organism could henceforth pass on some of its genetic material to produce new individuals and could itself become disposable with respect to the survival of its species. This classic biological idea has however been perturbed recently by the discovery that
10332-400: The enhancement of enzyme telomerase activity. 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
10458-418: The fact that the 191-amino acid protein is too large to be absorbed through the mucous membranes , and would be broken up in the stomach if swallowed. The Mprize scientific competition is under way to deliver on the mission of extending healthy human life. It directly accelerates the development of revolutionary new life extension therapies by awarding two cash prizes: one to the research team that breaks
10584-758: 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. Some tech innovators and Silicon Valley entrepreneurs have invested heavily into anti-aging research. This includes Jeff Bezos (founder of Amazon ), Larry Ellison (founder of Oracle ), Peter Thiel (former PayPal CEO), Larry Page (co-founder of Google ), Peter Diamandis , Sam Altman (CEO of OpenAI , invested in Retro Biosciences ), and Brian Armstrong (founder of Coinbase and NewLimit), Bryan Johnson (Founder of Kernel ). Leon Kass (chairman of
10710-482: The genus Hydra have a regenerative ability by which they avoid dying of old age. Early life forms on Earth, starting at least 3.7 billion years ago, were single-celled organisms. Such organisms ( Prokaryotes , Protozoans , algae ) multiply by fission into daughter cells; thus single celled organisms have been thought to not age and to be potentially immortal under favorable conditions. However, evidence has been reported that aging leading to death occurs in
10836-677: The human lifespan , either modestly through improvements in medicine or dramatically by increasing the maximum lifespan beyond its generally-settled biological limit of around 125 years . Several researchers in the area, along with "life extensionists", " immortalists ", or " longevists " (those who wish to achieve longer lives themselves), postulate 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 through complete rejuvenation to
10962-408: The impact on health care demand. The large number of suggestions in the literature for specific interventions to cope with the expected increase in demand for long-term care in ageing societies can be organized under four headings: improve system performance; redesign service delivery; support informal caregivers; and shift demographic parameters. However, the annual growth in national health spending
11088-616: The industry has also expanded; the kinds of products they produce (such as serums and creams) have gradually gained popularity and become a part of many people's personal care routine. The increase in demand for cosmeceuticals has led scientists to find ingredients for these products in unorthodox places. For example, the secretion of cryptomphalus aspersa (or brown garden snail) has been found to have antioxidant properties, increase skin cell proliferation, and increase extracellular proteins such as collagen and fibronectin (important proteins for cell proliferation). Another substance used to prevent
11214-492: The internal processes (epigenetic maintenance such as DNA methylation ) inherently may cause ageing. Programmed ageing should not be confused with programmed cell death ( apoptosis ). Human beings and members of other species, especially animals, age and die. Fungi, too, can age. In contrast, many species can be considered potentially immortal : for example, bacteria fission to produce daughter cells, strawberry plants grow runners to produce clones of themselves, and animals in
11340-452: The lens of the damage theory, proposing nine metabolic "hallmarks" of ageing in various organisms but especially mammals: There are three main metabolic pathways which can influence the rate of ageing, discussed below: It is likely that most of these pathways affect ageing separately, because targeting them simultaneously leads to additive increases in lifespan. The rate of ageing varies substantially across different species, and this, to
11466-508: The longest extension of life caused by a single gene manipulation was roughly 50% in mice and 10-fold in nematode worms. In July 2020 scientists, using public biological data on 1.75 m people with known lifespans overall, identify 10 genomic loci which appear to intrinsically influence healthspan , lifespan, and longevity – of which half have not been reported previously at genome-wide significance and most being associated with cardiovascular disease – and identify haem metabolism as
11592-459: The maintenance of interpersonal relationships and promoting successful ageing. At the same time, older persons can make contributions to society including caregiving and volunteering. For example, "A study of Bolivian migrants who [had] moved to Spain found that 69% left their children at home, usually with grandparents. In rural China, grandparents care for 38% of children aged under five whose parents have gone to work in cities." Population ageing
11718-788: The mechanisms that cause NMJ degradation. A meta-analysis showed that loneliness carries a higher mortality risk than smoking. Different cultures express age in different ways. The age of an adult human is commonly measured in whole years since the day of birth. (The most notable exception— East Asian age reckoning —is becoming less common, particularly in official contexts.) Arbitrary divisions set to mark periods of life may include juvenile (from infancy through childhood , preadolescence , and adolescence), early adulthood , middle adulthood , and late adulthood . Informal terms include " tweens ", "teenagers", "twentysomething", "thirtysomething", etc. as well as "denarian", "vicenarian", "tricenarian", "quadragenarian", etc. Most legal systems define
11844-490: The mice to age prematurely and suffer ailments. When the mice were given injections to reactivate the enzyme, it repaired the damaged tissues and reversed the signs of aging. There are at least eight important hormones that decline with age: 1. human growth hormone (HGH); 2. the sexual hormones: testosterone or oestrogen/progesterone; 3. erythropoietin (EPO); 4. insulin; 5. DHEA ; 6. melatonin; 7. thyroid; 8. pregnenolone. In theory, if all or some of these hormones are replaced,
11970-620: The most well known examples of this, dealing with the short- and long-term effects of a near perfect 80-year-old to 20-year-old body change with mind intact. The less perfect rejuvenation featured in the Mars trilogy by Kim Stanley Robinson results in long-term memory loss and sheer boredom that comes with extreme age. The post-mortal characters in the Revelation Space series have long-term or essentially infinite lifespans, and sheer boredom induces them to undertake activities of extreme risk. Aging
12096-562: The much longer lives of even small mammals, such as the mouse (around 3 years). A model organism for the study of ageing is the nematode C. elegans – having a short lifespan of 2–3 weeks – enabling genetic manipulations or suppression of gene activity with RNA interference , and other factors. Most known mutations and RNA interference targets that extend lifespan were first discovered in C. elegans . The factors proposed to influence biological ageing fall into two main categories, programmed and error-related . Programmed factors follow
12222-399: The mythical substance that, as it was believed, could not only turn lead into gold, but also prolong life and restore youth. Although the set goal was not achieved, alchemy paved the way to the scientific method and so to the medical advances of today. Serge Abrahamovitch Voronoff was a French surgeon born in Russia who gained fame for his technique of grafting monkey testicle tissue on to
12348-714: The person healthier or live longer, but the real improvement in a person's appearance may elevate their mood and have positive side effects normally correlated with happiness . Cosmetic surgery is a large industry offering treatments such as removal of wrinkles ("face lift"), removal of extra fat (liposuction) and reshaping or augmentation of various body parts ( abdomen , breasts , face ). There are also, as commonly found throughout history, many fake rejuvenation products that have been shown to be ineffective. Chief among these are powders, sprays, gels, and homeopathic substances that claim to contain growth hormones. Authentic growth hormones are only effective when injected, mainly due to
12474-587: The physical manifestations of ageing is onobotulinumtoxinA, the toxin injected for Botox. In some cultures, old age is celebrated and honoured. In Korea, for example, a special party called hwangap is held to celebrate and congratulate an individual for turning 60 years old. In China, respect for elderly is often the basis for how a community is organized and has been at the foundation of Chinese culture and morality for thousands of years. Older people are respected for their wisdom and most important decisions have traditionally not been made without consulting them. This
12600-490: 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 . Replacement of biological (susceptible to diseases) organs with mechanical ones could extend life. This is the goal of the 2045 Initiative . Cryonics is the low-temperature freezing (usually at −196 °C or −320.8 °F or 77.1 K) of
12726-537: 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 . Research by Sobh and Martin (2011) suggests that people buy anti-aging products to obtain
12852-421: The possibility of growing human body parts on mice. 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
12978-423: The potential role of embryonic stem cells in life extension. 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"; transhumanist philosopher Zoltan Istvan , who proposes that the "transhumanist must safeguard one's own existence above all else"; futurist George Dvorsky , who considers aging to be
13104-559: The principals of the organization, were jailed for four hours and were released on $ 850,000 bond each. After 11 years of legal battles, Kent and Faloon convinced the US Attorney's Office to dismiss all criminal indictments brought against them by the FDA. In 2003, Doubleday published "The Immortal Cell: One Scientist's Quest to Solve the Mystery of Human Aging," by Michael D. West . West emphasised
13230-403: The rate varies depending on the type and may, in fact, remain steady throughout most of the human lifespan, dropping suddenly only as people near the end of their lives. Individual variations in the rate of cognitive decline may therefore be explained in terms of people having different lengths of life. There are changes to the brain: after 20 years of age, there is a 10% reduction each decade in
13356-469: The reproductive years and lasts into old age – is essential for the physical and emotional well-being of older persons, and, indeed, all people. Public policies and programmes should additionally address the needs of older impoverished people who cannot afford health care." Many societies in Western Europe and Japan have ageing populations. While the effects on society are complex, there is a concern about
13482-446: The risk for physical and mental conditions such as anxiety, depression, and cognitive decline. [2] A distinction can be made between "proximal ageing" (age-based effects that come about because of factors in the recent past) and "distal ageing" (age-based differences that can be traced to a cause in a person's early life, such as childhood poliomyelitis ). Ageing is among the greatest known risk factors for most human diseases . Of
13608-602: The risk of falls in the elderly, which is a key factor for living a longer and healthier life. In terms of programming, there is no one-size-fits-all approach. General recommendations for improvements to gait speed, strength, and muscle size for reduced fall risk are resistance training programs with two to three 40-60 minute workouts per week, consisting of 1-2 sets of 5-8 repetitions of 2-3 different exercises for each major muscle group, but individual considerations must be taken due to differences in health status, motivation, and accessibility to exercise facilities. There
13734-401: The roughly 150,000 people who die each day across the globe, about two-thirds die from age-related causes. Certain lifestyle choices and socioeconomic conditions have been linked to ageing. Current ageing theories are assigned to the damage concept, whereby the accumulation of damage (such as DNA oxidation ) may cause biological systems to fail, or to the programmed ageing concept, whereby
13860-421: The roughly 150,000 people who die each day across the globe, about two-thirds--100,000 per day--die from age-related causes . In industrialized nations, the proportion is higher, reaching 90%. In the 21st century, researchers are only beginning to investigate the biological basis of ageing even in relatively simple and short-lived organisms, such as yeast . Little is known of mammalian ageing, in part due to
13986-736: The same effect on the aging process as a CR diet, which are known as caloric restriction mimetic drugs, such as rapamycin and metformin . Sirtuin activating polyphenols , such as resveratrol and pterostilbene , and flavonoids , such as quercetin and fisetin , as well as oleic acid are dietary supplements that have also been studied in this context. Other common supplements with less clear biological pathways to target aging include lipoic acid , senolytics , and coenzyme Q10 . While agents such as these have some limited laboratory evidence of efficacy in animals, there are no studies to date in humans for drugs that may promote life extension, mainly because research investment remains at
14112-413: The search and many perished. The Fountain was nowhere to be found as locals were unaware of its exact location. Since the emergence of philosophy , sages and self-proclaimed wizards always made enormous efforts to find the secret of youth, both for themselves and for their noble patrons and sponsors . It was widely believed that some potions may restore the youth. Another commonly cited approach
14238-405: The single-cell bacterium Escherichia coli , an organism that reproduces by morphologically symmetrical division. Evidence of aging has also been reported for the bacterium Caulobacter crescintus . and the single cell yeast Saccharomyces cerevisiae . Ageing and mortality of the individual organism became more evident with the evolution of eukaryotic sexual reproduction , which occurred with
14364-409: The stories about the quest for rejuvenation. It was believed that magic or intervention of a supernatural power can bring back youth and many mythical adventurers set out on a journey to do that, for themselves, their relatives or some authority that sent them anonymously. An ancient Chinese emperor actually sent out ships of young men and women to find a pearl that would rejuvenate him. This led to
14490-459: The superficial chemical properties of a young body". 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. In 2008, the US Department of Defense announced a program to research
14616-554: The testicles of men while working in France in the 1920s and 1930s. This was one of the first medically accepted rejuvenation therapies (before he was proved to be wrong around 1930–1940). The technique brought him a great deal of money, although he was already independently wealthy. As his work fell out of favor, he went from being a highly respected surgeon to a subject of ridicule. By the early 1930s, over 500 men had been treated in France by his rejuvenation technique, and thousands more around
14742-467: The total length of the brain's myelinated axons . Age can result in visual impairment , whereby non-verbal communication is reduced, which can lead to isolation and possible depression. Older adults, however, may not experience depression as much as younger adults, and were paradoxically found to have improved mood, despite declining physical health. Macular degeneration causes vision loss and increases with age, affecting nearly 12% of those above
14868-529: 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 . While some biogerontologists find these ideas "worthy of discussion", others contend that the alleged benefits are too speculative given the current state of technology, referring to it as "fantasy rather than science". Genome editing , in which nucleic acid polymers are delivered as
14994-458: The very notion of a "life-extension factor" that could apply across taxa presumes a linear response rarely seen in biology." There are numerous chemicals intended to slow the aging process under study in animal models . One type of research is related to the observed effects of a calorie restriction (CR) diet, which has been shown to extend lifespan in some animals. Based on that research, there have been attempts to develop drugs that will have
15120-720: The workplace and can also cost more in worker's compensation and pension liabilities. In most developed countries an older workforce is somewhat inevitable. In the United States for instance, the Bureau of Labor Statistics estimates that one in four American workers will be 55 or older by 2020. Among the most urgent concerns of older persons worldwide is income security. This poses challenges for governments with ageing populations to ensure investments in pension systems continues to provide economic independence and reduce poverty in old age. These challenges vary for developing and developed countries. UNFPA stated that, "Sustainability of these systems
15246-435: The world record for the oldest-ever mouse; and one to the team that develops the most successful late-onset rejuvenation. Current Mprize winner for rejuvenation is Steven Spindler. Caloric restriction (CR), the consumption of fewer calories while avoiding malnutrition, was applied as a robust method of decelerating aging and the development of age-related diseases . The biomedical gerontologist Aubrey de Grey has initiated
15372-462: The world, such as in a special clinic set up in Algiers . Noteworthy people who had the surgery included Harold McCormick , chairman of the board of International Harvester Company , and the aging premier of Turkey . Rejuvenation technology and its effects on individuals and society have long been a subject of science fiction. The Misspent Youth and Commonwealth Saga by Peter F. Hamilton are among
15498-495: 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. 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"
15624-410: The young or old. Each nation, government, and non-governmental organization has different ways of classifying age. In other words, chronological ageing may be distinguished from "social ageing" (cultural age-expectations of how people should act as they grow older) and "biological ageing" (an organism's physical state as it ages). Ageism cost the United States $ 63 billion in one year according to
15750-434: 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. 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
15876-453: Was attempting to transfer the essence of youth from young people to old. Some examples of this approach were sleeping with virgins or children (sometimes literally sleeping, not necessarily having sex), bathing in or drinking their blood. The quest for rejuvenation reached its height with alchemy . All around Europe, and also beyond, alchemists were looking for the Philosopher's Stone ,
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