Anti aging

from Wikipedia, the free encyclopedia

The term anti-aging , also old age prevention , is a term for measures that aim to delay the biological aging of humans, to maintain the quality of life in old age at a high level for as long as possible and also to extend life expectancy as a whole. This term is used in medicine, by nutritionists, the dietary supplement industry, by cosmetics manufacturers and also partly in connection with cosmetic surgery . Antiaging is a marketing term .

Anti-aging differs from rejuvenation : While anti-aging aims to slow down aging processes, these are to be reset through rejuvenation measures.

Age research / biogerontology

If we did not age as we do now, according to D. Pearson / S. Shaw lived an average of about 800 years, according to Randolph M. Nesse and George C. Williams about 690 years. The lifespan would only be limited by accidents, suicide or suicide and illness. The average life expectancy (LE) has increased significantly in the countries of the First World in recent times, but the maximum achievable age seems to have been constant at around 120 years (up to 122 years) for a very long time, without being foreseeable at the moment that this value can be influenced by anti-aging measures in the future, as it may be genetically determined.

Scientists in biogerontology are convinced that the process of physical aging is caused by several factors at the same time, of which only a few can be influenced to a limited extent. A distinction is made in principle:

Scientific studies on twin research have shown that around 30 percent of life expectancy is determined by genes . Other studies estimate the importance of genetic causes to be higher and come to a value of 70%. Those who come from a family in which several ancestors have reached old age also have a statistically higher life expectancy. Longevity is an inheritable trait. A large number of genes (death genes, longevity assurance genes) have now been identified in living things.
  • Aging due to lifestyle and environmental influences
It has been shown that lifestyle and environmental conditions influence the process of aging. Tobacco smoking and high alcohol consumption, too little sleep, obesity , stress , but also traffic noise and environmental pollution have negative effects .
  • Biochemical aging / attrition theories
Biochemical aging is a process that takes place in the body and in which free radicals play an essential role. They are permanently produced as waste products of the metabolism and are considered to be potentially damaging to cells. According to some researchers, they can be partially rendered harmless by adding certain vitamins , lipoic acid or selenium . However, there are no human studies to prove this.
  • Hormonal aging
Throughout life, the production decreases of various hormones in the body continuously, which as a major cause of the aging process and diseases such as dementia , osteoarthritis , osteoporosis and also from cancer is considered.

According to the current state of knowledge, age researchers assume that ideally people can live to be around 120 years old. It is well known that very few actually live to this age. One goal of the research is to fathom the conditions that promote the attainment of a very old age. Since 1976 there have been studies by the national health institutes of the USA and the Japanese Ministry of Health on the island of Okinawa , on which an above-average number of people who are at least 100 years old live, namely around 600 out of a total of 1.3 million inhabitants. Okinawa is the poorest prefecture in Japan; the people live mainly from fishing.

A relatively large number of very old people also live in Sardinia and Nova Scotia . In the Mediterranean countries, the rate of lifestyle diseases is lower than in the rest of Central Europe. To this day there is also a rumor that the Hunza people are particularly long-lived. However, this assumption has been scientifically refuted; this theory was probably based on a pure estimate based on the appearance of older people of this ethnic group.

Studies

It is difficult to prove an actual life extension. This requires large comparison groups that are randomized, prospectively and, preferably, double-blindly treated with different substances. After about 5 to 10 years, the mortality is compared.

Vitamin E and C do not protect against heart attacks

Although the market for anti-aging agents, especially hormones, vitamins and trace elements, is growing, the effectiveness of these strict criteria could not be guaranteed. For example, the so-called antioxidants vitamin E and C were ineffective in preventing heart attacks in large studies such as the English Heart Protection Study.

Folic acid protects against heart attacks and strokes

On the other hand, folic acid, a vitamin from the B group, has shown a good effect against circulatory diseases such as heart attacks and strokes in several studies.

Increase in life expectancy by combating arteriosclerosis

The following drugs may have a positive effect on the life expectancy of a part of the population that is prone to arteriosclerosis (men over 50, women over 65):

  • Antihypertensive drugs such as ACE inhibitors in people who suffer from abnormally high blood pressure ( arterial hypertension ). A superior effect of particular groups of substances has not yet been proven. Only an effective lowering of blood pressure has been proven.
  • Anti-inflammatory and platelet aggregation inhibitors (e.g. acetylsalicylic acid ). In 1852, Rudolf Virchow recognized arteriosclerosis as the primary inflammation of the arteries. Today it is described as epithelial dysfunction in the initial stage of arteriosclerosis
  • Cholesterol-lowering drugs , such as statins , have so far only been tested in coronary risk patients. The ALLHAT-LLT study showed no effect of the intervention, while the ASCOT-LLA study claims to have found an effect. The latter study shows noticeable shortcomings. It was discontinued early while the ALLHAT-LLT trial was correctly completed.
  • Omega-3 fatty acids

Lowering cardiovascular risks through omega-3 fatty acids

EicosaPentaenic Acid and DocosaHexaenic Acid are components of the cell membrane and have a modulating effect on the function of various cells. That is why there is not a single mechanism of action of these two omega-3 fatty acids, but rather a wide variety. The following effects for EPA and DHA have been demonstrated in human studies:

The short chain (vegetable) α-linolenic acid (18: 3 ω-3) can be obtained by competitive inhibition of the linoleic acid (18: 2 ω-6) by the desaturase - and elongase displace enzymes and therefore the production and tissue concentrations of inflammatory arachidonic reduce .

So far, the results of four large clinical intervention studies on a total of more than 30,000 people are available: Diet and Reinfarction Trial (DART), Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico-Prevenzione (GISSI-P), DART-2, and Japan EPA Lipid Intervention Study. (JELIS). DART and GISSI-P showed a reduction in all-cause mortality between 20 and 29 percent of sudden cardiac death of around 45 percent and cardiac events after administration of just under one gram of EPA and DHA per day. DART-2 was surveyed so poorly that reliable conclusions could not be drawn. JELIS was attended by 18,645 hyperlipidemic Japanese people with additional cardiovascular risk factors for five years. Traditionally, a lot of fish, including EPA and DHA, is consumed in Japan, which leads to high levels. These levels were further increased by the administration of 1.8 grams per day of eicosapentaenoic acid. The incidence of sudden cardiac death in JELIS was 40 per 100,000, which is well below the incidence of the general German population (see above). Other cardiac events were also rare in JELIS and were further reduced by taking eicosapentaenoic acid.

Thymic therapy

According to a study published in April 2014, the mouse model succeeded in increasing the size of the thymus, which had shrunk with age, by upregulating the transcription factor FOXN1 . The treated mice showed a significant increase in output of the CD4 and CD8 T cells produced in the thymus, which is equivalent to an increased immune competence.

Melatonin lowers blood pressure, protects the heart and reduces the risk of migraines and cancer

According to Johannes Huber, melatonin lowers the stress hormones, reduces blood pressure and thus protects the heart. People with cardiovascular disease have a low melatonin level, especially at night, and accordingly prefer to develop high blood pressure or other cardiovascular complications at night. Indirectly, this can slow down the further development of renal insufficiency (with the risk of later need for dialysis treatment or kidney transplants), which is primarily a consequence of high blood pressure. Numerous independent studies have verified that a low nocturnal melatonin level is an additional risk factor for the development of cancer and particularly of hormone-dependent tumors such as prostate cancer and breast cancer (breast cancer).

There is much to suggest that the aging process is actually a physical process - just as our entire organism is subject to physics and electronics. Electron transfers play an important role in physical processes and are the prerequisite for life in our body, but they also trigger aging. The hormone of the "night", melatonin, counteracts the active processes of the day, it slows down the flow of electrons and although it reduces our performance capacity, which is not in demand at night, the radicals are reduced, and even more so, the melatonin catches this one more.

Melatonin review

The anti-aging hormones include melatonin , which is produced in the pineal gland and controls the human sleep-wake cycle. The body's own production decreases with age, which among other things can lead to sleep disorders . The hypothesis that melatonin could show an anti-aging effect in humans goes back on the one hand to the Swiss researchers Maestroni and Pierpaoli, on the other hand to the US researcher Russell J. Reiter.

In the US, melatonin supplements are considered a “miracle cure” and are freely available in stores. The scientific proof that melatonin actually delays “aging” is missing so far, although several studies show positive effects on cognitive function; Long-term studies on possible side effects are also lacking . Melatonin would have to be taken preventively in relatively high doses, which would result in a disruption of circadian rhythms if this were not taken regularly every day at a certain time. Strictly speaking, the treatment would have to start in childhood, which is forbidden because of the disruptive effects of melatonin on children's sexual development. Melatonin was also talked about for a while as the “pill for men” and is considered a “weapon” against free radicals .

Anti aging therapies

Way of life

Anti-aging therapy is very inconsistently different measures. This can range from the therapeutic treatment of certain age-related diseases such as Alzheimer's disease and memory training to nutritional advice and the use of nutritional supplements and hormone therapies. On the basis of the available research results, the various anti-aging experts generally recommend things that can generally promote health:

  • Balanced diet
  • Avoidance of obesity and moderate "starvation"
  • Regular exercise (consumption of at least 8,370 to 12,560 kJ of food energy per week, in outdated units approx. 2,000 to 3,000 kcal per week); see also senior sports
  • Quit smoking
  • Refrain from extensive sunbathing and visits to solariums
  • Avoidance of negative stress

Hormone substitution in aging people is controversial among medical professionals. Hormone administration can also have negative effects, as studies show. Long-term use of female hormones is suspected of increasing the risk of tumor growth .

nutrition

A high daily intake of vitamins A, C and E and selenium is often recommended in order to curb the harmful effects of free radicals. With such a procedure, however, the corresponding substances would have to be given in high doses for life. Too high a dose of vitamin C in turn leads to an increase in the concentration of free radicals, especially in the presence of free iron, which calls into question a possible effect. In addition, it is often advised to avoid red meat, animal fats, sugar, regular coffee and alcohol consumption and nicotine. Instead of red wine, “red grape juice” or “grape extract from red grapes and seeds” is recommended. The gelatine manufacturers claim that by taking 10 grams of their product daily, the connective tissue is strengthened and the depth of wrinkles in the skin is reduced.

There is evidence that an above-average number of people who live to be over 100 years old live in Okinawa and Sicily ; Births are officially recorded on both islands. In contrast, there is no official evidence for the Hunzukuc's age, for example . On Okinawa, the inhabitants mainly eat fish, nori , Goya cucumber , soy , tofu , cabbage, sweet potatoes , fruit and green tea. A lot of vegetables are eaten in Sicily, and fish and olive oil play an important role in the diet.

Since most people who live to be over 100 years old are slim and tend to be underweight , which is also said to be the case in Okinawa and Sicily, there is also the tip to reduce the daily calorie intake and never to completely during meals Satiety to eat.

At the University of Vienna, a group of 110 healthy people showed that taking a dietary supplement with special plant substances, minerals and vitamins can have a positive effect on telomere length . The total telomere length showed a significant increase by an average of 17.77% without increasing telomerase activity.

A lifelong hypocaloric diet ( calorie restriction ) increases the life expectancy of animals, but also of protozoa, and has so far been proven in mice, rats, fish, flies and spiders. In animal experiments on mice, but also with great apes, a constant, light “starvation diet” has increased the age by up to 40 percent, with yeast cells by 70 percent. In mice this corresponds to a plus of two years. Followers of a permanent under-calorie diet refer to themselves as cronie .

Some scientists doubt that the results can be transferred to humans. In addition, a constant low-calorie diet also has undesirable side effects. Bone loss has been found in monkeys, the body temperature drops and the willingness to mate disappears.

Intermittent fasting is a variant of calorie restriction .

David Sinclair of Harvard Medical School in Boston is convinced that an extreme diet triggers an "emergency call" in the body's cells that drastically slows down the aging process. He found out in laboratory tests that this life-prolonging effect can be artificially triggered in vitro in yeast cells by the substance resveratrol from red wine . Whether the result can be transferred to humans is open.

Testosterone therapy

The testosterone level in men drops by up to one percent per year, so that in people aged 60 to 80 it is only 30 to 50% of the initial value. If the testosterone level is too low, the risk of heart attack increases significantly. However, extreme caution should be exercised with a history of heart attacks with testosterone administration. The administration of testosterone (+ training) increases muscle mass, which significantly improves mobility and quality of life in older men. In senior sport, Therapeutic Use Exemptions belong . for testosterone one of the most frequently used drugs, since athletic performance is significantly reduced when testosterone levels are low. The intake of testosterone in men with prostate cancer is controversial because, on the one hand, the results of research to date are highly contradictory, but on the other hand, there has also been a paradigm shift in prostate research.

Methods without proof of effectiveness

Fresh cell therapy

Until the 1990s, fresh cell therapy was also considered a possible “secret weapon” against aging processes; it was banned in Germany in 1997. The ban was lifted in 2000, but the therapy is no longer particularly popular. The following measures are recommended again and again, but have not been proven by large prospective studies.

Dehydroepiandrosterone

Dehydroepiandrosterone (DHEA) controls the production of sex hormones in both men and women. The concentration of DHEA in the body drops dramatically with age. Anti-aging doctors postulate that taking the substance has positive effects on muscle mass, skin becomes firmer and memory improves. There are also no reliable scientific studies on the positive effects of DHEA substitution. There are indications that tumors may be favored , but this is disputed by others, including the German Society of Anti-Aging-Medicine (GSAAM). As a single substance, DHEA has not yet been approved in Germany, but it is contained in preparations for the treatment of women going through menopause . The GSAAM emphasizes on its website: “ In the pharmaceutical test reports of the Federal Office for Pharmacological Safety, not a single side effect was reported, either in the oncological, metabolic or cardiological area. "

Growth hormones

Since a study published in 1990, the growth hormone somatotropin (HGH, Human Growth Hormone ) has been considered a particularly effective anti-aging agent. The followers advertise with statements such as fat loss, skin generation, prevention of diabetes mellitus , improvement of the metabolism and delayed aging. The formation of growth hormones also decreases continuously over the course of life. However, critics warn of incalculable risks. The aging researcher Christoph Bamberger points out that animal experiments have shown that the administration of growth hormones promotes cancer, as the substance generally stimulates all cells to grow, including any “sleeping” cancer cells that may be present .

In contrast, proponents of therapy with somatotropin refer to studies that prove the protective effect of this substance against cancer. The use of somatotropin should be carried out under the supervision of a specialized doctor who carries out the substitution in coordination with other deficient hormones. A monotherapy with somatotropin in multiple hormonal deficiency - as they usually present at midlife - not recommended because somatotropin for the distribution. B. cortisol slows down, which can reduce stress resistance. The only effective form of application is injection into the subcutaneous fatty tissue.

In contrast, it has been shown in various animal models that reduced levels of growth hormones and, as a result, IGF-1 levels significantly increase both mean and maximum life expectancy . Heterozygous female mice in which the IGF-1 receptor has been 'switched off' ( gene knockout ) accordingly have a longer life expectancy. Transgenic mice that express increased growth hormones , on the other hand, have a significantly reduced life expectancy, are sexually mature earlier and also show age-related changes significantly earlier than the wild type .

Thymic therapy

With increasing age, the activity of the thymus , which has an important function for the immune system, decreases ( immunosenescence ). To counteract this effect, formerly of thymus were sheep - embryos within the fresh cell therapy injected. Today, preparations made from dried thymus glands of adult sheep or pigs are usually administered orally. This therapy is offered by some doctors and alternative practitioners with the aim of strengthening the immune system. Sometimes it is also claimed that it can be used to fight cancer . It is also advertised that thymus supplements delay aging. There are no studies that scientifically substantiate these claims.

Removal of senescent cells

A removal of senescent cells in an organism leads to a later onset of age-related diseases and a longer average life span.

Anti-aging and cosmetics

The visible external sign of aging is skin aging , which begins around the age of 25 and becomes visible at some point, especially in the form of wrinkles. A distinction is again made between biological aging and aging due to external influences. Biologically, the rate of cell renewal slows down, the ability to store moisture decreases. In deeper skin layers is controlled by the enzyme collagenase increasing with age collagen degraded, so that the skin loses its elasticity.

The most important external factor in skin aging is exposure to UV radiation, also known as photoaging . The UV radiation creates free radicals that destroy cell components and cause cells to die. Extensive sunbathing and visits to the solarium in particular intensify this form of aging. " Age spots " are also sun damage . Also nicotine causes premature aging of the skin with wrinkles.

Since clearly visible wrinkles as a sign of aging are not considered desirable, at least in western cultures, numerous cosmetic products are advertised with the catchphrase anti-aging and the promise of wrinkle reduction. The term anti-aging is not protected by law, so it can be used as desired. The largest range on the market is for face creams, with various ingredients being advertised as "wrinkle killers". These include vitamin C, retinol , collagen, coenzyme Q10 , hyaluronic acid , but also caviar extract and even gold particles.

Stiftung Warentest regularly criticizes in their investigations the lack of or only brief and low or not proven effectiveness of the products.

The cosmetics industry and cosmetic medicine offer a wide range of methods to combat wrinkles under the terms anti-aging or pro-aging . The term is also often used for cosmetic surgery measures . The effect of all methods is limited in time to months or years and sometimes involves risks. The aging of the organism and the skin is in fact not affected.

Further information

See also

literature

Web links

Wiktionary: Anti-Aging  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ G. Schnyder et al .: Effect of Homocysteine-Lowering Therapy With Folic Acid, Vitamin B 12 , and Vitamin B 6 on Clinical Outcome After Percutaneous Coronary Intervention. In: JAMA. 288, 2002, pp. 973-979.
  2. ↑ Major outcomes in moderately hypercholesterolemic, hypertensive patients randomized to pravastatin vs usual care: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT-LLT). In: JAMA. 288, 2002, pp. 2998-3007. PMID 12479764
  3. ↑ PS Server ua: Prevention of coronary and stroke events with atorvastatin in hypertensive patients who have average or lower-than-average cholesterol concentrations, in the Anglo-Scandinavian Cardiac Outcomes Trial - Lipid Lowering Arm (ASCOT-LLA): a multicentre randomized controlled trial. In: The Lancet. 361, 2003, pp. 1149-1158. PMID 12686036
  4. ↑ B. London, C. Albert, ME Anderson et al .: Omega-3 Fatty acids and cardiac arrhythmias: prior studies and recommendations for future research: a report from the National Heart, Lung, and Blood Institute and Office Of Dietary Supplements Omega-3 Fatty Acids and Their Role In Cardiac . Arrhythmogenesis workshop. In: Circulation. 116, 2007, pp. E320 – e335.
  5. ↑ C. von Schacky: n-3 PUFA in CVD: influence of cytokine polymorphism. In: Proc Nutr Soc. 66, 2007, pp. 166-170.
  6. ↑ a b C. von Schacky: Omega-3's and cardiovascular disease: an update for 2007. In: Curr Op Nutr Metab Care. 10, pp. 129-135.
  7. ↑ a b c Omega-3 fatty acids: protection against stroke and infarction. In: Pharmaceutical newspaper. 4/2004.
  8. ^ Medical Study News: Brain fatty acid levels linked to depression. May 25, 2005, accessed February 10, 2006 .
  9. ↑ a b M. L. Burr, AM Fehily, JF Gilbert et al .: Effects of changes in fat, fish, and fiber intakes on death and myocardial infarction: diet and reinfarction trial (DART). In: Lancet. 2, 1989, pp. 757-761.
  10. ^ A b R. Marchioli, F. Barzi, E. Bomba et al.: Early protection against sudden death by n-3 polyunsaturated fatty acids after myocardial infarction. Time-course analysis of the results of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarcto Miocardio (GISSI) -Prevenzione. In: Circulation. 105, 2002, pp. 1897-1903 DART-1
  11. ^ A b A. R. Ness, PAL Ashfield-Watt, JM Whiting, GD Smith, J. Hughes, ML Burr: The long-term effect of dietary advice on the diet of men with angina: the diet and angina randomized trial. In: J Hum Nutr Diets. 17, 2004, pp. 117-119.
  12. ↑ a b c M. Yokoyama, H. Origasa, M. Matsuzaki, Y. Matsuzawa, Y. Saito, Y. Ishikawa, S. Oikawa, J. Sasaki, H. Hishida, H. Itakura, T. Kita, A. Kitabatake, N. Nakaya, T. Sakata, K. Shimada, K. Shirato; Japan EPA lipid intervention study (JELIS) ​​Investigators: Effects of eicosapentaenoic acid on major coronary events in hypercholesterolaemic patients (JELIS): a randomized open-label, blinded endpoint analysis. In: Lancet. 369, 2007, pp. 1090-1098. Erratum in: Lancet. 370, 2007, p. 220.
  13. ^ WS Harris, C. Von Schacky: The Omega-3 Index: a new risk factor for death from coronary heart disease? In: Prev Med. 39 (1), Jul 2004, pp. 212-220.
  14. ↑ http://dev.biologists.org/content/141/8/1627.full. (Link not available)
  15. ↑ a b Johannes Huber: Melatonin - long or intense life , melatonin reduces blood pressure and thus protects the heart, accessed on January 8, 2017
  16. ↑ Transsexuals: Beware of severe headache. ( Memento from February 12, 2008 in the Internet Archive ) on: medical-tribune.de , February 11, 2008.
  17. ↑ Rudolf Hänsel, Otto Sticher: Pharmakognosie - Phytopharmazie. 9th edition. Springer, 2009, ISBN 978-3-642-00962-4 , p. 347.
  18. ↑ GME: Everything about gelatin. ( Memento of October 16, 2013 in the Internet Archive ) p. 15.
  19. ↑ a b c d picture of science. 05/2005.
  20. ↑ Angelika Pointner, Ulrich Magnet, Elena Tomeva, Elisabeth Dum, Christina Bruckmueller: EGCG Containing Combined Dietary Supplement Affects Telomeres and Epigenetic Regulation . In: Journal of Nutrition & Food Sciences . tape 07 , no. 01 , 2017, doi : 10.4172 / 2155-9600.1000577 ( omicsonline.org [accessed May 22, 2019]).
  21. ↑ B. Lapauw, S. Goemaere, H. Zmierczak et al: The decline of serum testosterone levels in community-dwelling men over 70 years of age: descriptive data and predictors of longitudinal changes. In: Eur J Endocrinol. 159 (4), Oct 2008, pp. 459-468.
  22. ^ Z. Hyde, PE Norman, LJ Flicker et al: Low free testosterone predicts mortality from cardiovascular disease but not other causes: the Health in Men Study. In: Clin Endocrinol Metab. 97 (1), Jan 2012, pp. 179-189.
  23. ↑ S. Basaria, AD Coviello, TG Travison include: Adverse events associated with testosterone administration. In: N Engl J Med. 363 (2), Jul 8, 2010, pp. 109-122.
  24. ^ FR Sattler, C. Castaneda-Sceppa, EF Binder et al.: Testosterone and growth hormone improve body composition and muscle performance in older men. In: J Clin Endocrinol Metab. 94 (6), Jun 2009, pp. 1991-2001.
  25. ^ Arnd Krüger : Olympic Games as a means of politics. In: Eike Emrich, Martin-Peter Büch, Werner Pitsch (eds.): Olympic Games - still up to date? Values, goals, reality from a multidisciplinary perspective. Univ. d. Saarlandes, Saarbrücken 2013, pp. 35–54.
  26. ↑ JR Kovac, MM Pan, LI Lipshultz et al .: Current state of practice regarding testosterone supplementation therapy in men with prostate cancer. In: Steroids. 89C, Nov 2014, pp. 27-32.
  27. ↑ A. Morgentaler, Traish: Shifting the paradigm of testosterone and prostate cancer: the saturation model and the limits of androgen-dependent growth. In: AM.Eur Urol. 55 (2), Feb 2009, pp. 310-320.
  28. ↑ D. Rudman et al .: Effects of human growth hormone on men over 60 years old . In: New England Journal of Medicine . No. 323 , 1990, pp. 1-6 .
  29. ↑ A. Bartke et al.: Genes that prolong life: relationships of growth hormone and growth to aging and life span. ( Memento of January 8, 2009 in the Internet Archive ) In: J Gerontol A Biol Sci Med Sci. 56, 2001, pp. B340-B349. PMID 11487592 .
  30. ↑ M. Holzenberger et al .: IGF-1 receptor regulates lifespan and resistance to oxidative stress in mice. In: Nature. 421, 2003, pp. 182-187. PMID 12483226 .
  31. ↑ A. Bartke: Is growth hormone deficiency a beneficial adaptation to aging? Evidence from experimental animals. In: Trends Endocrinol Metab. 14, 2003, pp. 340-344. PMID 12946877 .
  32. ↑ R. Giordano et al: Growth hormone treatment in human aging: benefits and risks. In: Hormones. 7, 2008, pp. 133-139. PMID 18477550 .
  33. ↑ Darren J. Baker, Bennett G. Childs, Matej Durik, Melinde E. Wijers, Cynthia J. Sieben, Jian Zhong, Rachel A. Saltness, Karthik B. Jeganathan, Grace Casaclang Verzosa, Abdulmohammad Pezeshki, Khashayarsha Khazaie, Jordan D. Miller, Jan M. van Deursen: Naturally occurring p16Ink4a-positive cells shorten healthy lifespan. In: Nature. 2016, doi: 10.1038 / nature16932 .
  34. ↑ Werner Voss: Skin aging from a medical point of view. ( Memento from July 17, 2013 in the Internet Archive ) (PDF file, 121 kB).
  35. ↑ Cornelia Stolze : Traces of Time. Skin aging. In: Ratgeber Haut. stern.de , September 9, 2008, accessed November 25, 2010 .
  36. ↑ Test Anti-Age Creams Stiftung Warentest , April 25, 2002.
  37. ↑ Test anti-wrinkle creams Stiftung Warentest , 3/2007.