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Several drugs and food supplements have been shown to retard or reverse the biological effects of ageing in animal models; none has yet been proven to do so in humans. Transcendental Meditation (TM technique) may have beneficial age-related effects.[79][80][81][82][83] In 2002, a team led by Professor Bruce Ames at UC Berkeley discovered that feeding aged rats a combination of acetyl-L-carnitine and alpha-lipoic acid (both substances are already approved for human use and sold in health food stores) produced a rejuvenating effect.[84] Ames said, "With these two supplements together, these old rats got up and did the macarena. The brain looks better, they are full of energy – everything we looked at looks like a young animal." UC Berkeley has patented the use of these supplements in combination and a company, Juvenon, has been established to market the treatment. In 2007, researchers at the Salk Institute for Biological Studies identified a critical gene in nematode worms that specifically links eating fewer calories with living longer. Professor Andrew Dillin and colleagues showed that the gene pha-4 regulates the longevity response to calorie restriction.[85] In the same year Dr Howard Chang of the Stanford University School of Medicine was able to rejuvenate the skin of two-year-old mice to resemble that of newborns by blocking the activity of the gene NF-kappa-B.[86] In 2008, a team at the Spanish National Cancer Research Center genetically engineered mice to produce ten times the normal level of the telomerase enzyme.[87] The mice lived 26% longer than normal.[88] Also in 2008, a team led by Professor Michael O Thorner at the University of Virginia discovered that the drug MK-677 restored 20% of muscle mass lost due to ageing in humans aged 60 to 81. The subjects' growth hormone and insulin-like growth factor 1 (IGF-1) levels increased to that typical of healthy young adults.[89] In 2009, a drug called rapamycin, discovered in the 1970s in the soil of Easter Island in the South Pacific, was found to extend the life expectancy of 20-month-old mice by up to 38%.[90] Rapamycin is approved for human use and is generally used to suppress the immune system and prevent the rejection of transplanted organs. It is thought to mimic the effect of calorie restriction.[91] Dr Arlan Richardson of the Barshop Institute said, "I never thought we would find an anti-ageing pill in my lifetime; however, rapamycin shows a great deal of promise to do just that."[this quote needs a citation] Professor Randy Strong of the University of Texas Health Science Center at San Antonio said, "We believe this is the first convincing evidence that the ageing process can be slowed and lifespan can be extended by a drug therapy starting at an advanced age."[this quote needs a citation] Also in 2009, the British Journal of Nutrition reported a study at Tufts University in Boston which showed that brain function and motor skills in aged rats could be improved by adding walnuts to their diet. The human equivalent would be to eat seven to nine walnuts per day.[92] Another drug already approved for human use (for the treatment of diabetes), metformin has been shown to increase mouse lifespan by about five percent when treatment is started in middle age.[93] In September 2009, researchers at UC Berkeley discovered they could restore youthful repair capability to muscle tissue taken from men aged 68 to 74 by in vitro treatment with mitogen-activated protein kinase.[94] This protein was found to be essential for the production of the stem cells necessary to repair muscle[95] after exercise and is present at reduced levels in aged individuals. Ronald A. DePinho, a cancer geneticist at the Dana-Farber Cancer Institute and Harvard Medical School, published a paper[96] in Nature magazine in November 2010 which indicated that the organs of genetically altered mice, designed to activate telomerase after feeding them with a chemical, were rejuvenated. Shrivelled testes grew back to normal and the animals regained their fertility. Other organs, such as the spleen, liver, intestines and brain, recuperated from their degenerated state. Dr Lynne Cox of Oxford University said, "This paper is extremely important as it provides proof of the principle that short-term treatment to restore telomerase in adults already showing age-related tissue degeneration can rejuvenate aged tissues and restore physiological function."[this quote needs a citation] In this experiment mice were engineered to not produce telomerase naturally but after a chemical "switch" the system would then restore telomerase. Importantly, this chemical does not have the ability to produce telomerase in animals that are not genetically altered. Moreover, telomerase activation is also associated with the growth of cancerous tumours which could prevent anti-ageing treatments using this discovery. mTOR inhibition and the frequent activation of autophagy has been shown to increase longevity in model organisms such as yeast, flies and mice. mTor inhibition and autophagy have also been linked to insulin sensitivity and the reduction of reactive oxygen species damage, which is another major proposed cause to aging. It has become clear that autophagy activation in the body by mTOR inhibition increases longevity. mTOR inhibition reduces Reactive Oxygen Species damage by activating autophagy, which will recycle the damaged parts of cells and re use them for functioning parts. This process reduces ROS damage to a reasonable amount, therefore increasing longevity. mTOR inhibition has also been linked to other major aging diseases. mTOR inhibition has helped treat neurodegenerative diseases like Alzheimer’s in mice. It has also been used to reduce tumor growth in several cancers including renal, breast and several other rare cancers. Finally mTOR inhibition is also linked to reducing obesity and increasing immune function. The mTOR inhibition reduces the likelihood of diet induced and age induced obesity in mice, but in some cases led to glucose intolerance. Caloric restriction and exercise are two ways to activate autophagy and inhibit mTOR which can help resolve all of these common age related health issues.[70] In December 2013 a study, published in the journal Cell, detailed work carried out by researchers in: Australia - (University of NSW), in Portugal - (Center for Neurosciences and Cell Biology; University of Coimbra; and University of Aveiro) and in the USA - (Harvard University; Massachusetts Institute of Technology; and National Institutes of Health). Researchers reversed the ageing process in the muscles of mice, making two-year-old mice appear to be six months old. Research has shown that declining NAD+ during aging causes pseudohypoxia and that raising nuclear NAD+ in old mice reverses pseudohypoxia and metabolic dysfunction, thus reversing the aging process.[97] [98] The study involved injecting NAD into the mice. This reversed pseudohypoxia and metabolic dysfunction and thus the ageing process. It has been reported that human trials will begin in 2014. [99] |
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