The levels of many hormones go down with age. Some of the oldest and still most popular anti-aging treatments are thus based on the notion that hormonal changes contribute to aging and reversing age-related hormonal changes will be beneficial. The most famous of these treatments involves human growth hormone (hGH) injections. Growth hormone has a long history as an anti-aging treatment and some evidence suggests hGH has beneficial effects in elderly people: hGH supplements might increase muscle mass, strengthen the immune system and increase libido. There are studies in elderly patients in which they claim to feel younger after hGH treatment. While hGH was once hailed as a major breakthrough, like many other anti-aging products it failed to live up to expectations, in part because of its negative side-effects. These might include weight gain, high blood pressure and diabetes. Because, as the name implies, hGH stimulates growth, concerns have also been raised as to whether hGH could stimulate cancer growth and whether it will contribute to cancer development in patients with existing malignant or pre-malignant tumors.
Studies in mice do not by and large suggest a beneficial role for GH. If any, they suggest a harmful role. Though one study found that a low-dose GH therapy increases lifespan in aged mice, mice genetically modified to produce lots of GH live less than controls while mice producing less GH live longer. Of course, as mentioned above, studies in animals are not always relevant to human biology. Nonetheless, the results in mice suggest that higher GH levels will not make you live longer. Studies in humans with a deficiency in GH signalling due to a defect in the GH receptor also suggest a strong cancer protection due to decreased GH signalling. The human studies also hint at a sort of supernova effect: hGH makes patients feel better but might actually diminish their lifespan. In conclusion, hGH might be useful in certain aged patients, for example its use has been suggested in cases of depression, but by and large it should be seen as cocaine for granddad. Lastly, I should point out that there are (young) patients with GH deficiency that if untreated have a reduced longevity, so hGH does have clinical applications.
Insulin-like growth factor 1 (IGF-1) is another hormone that may play a role in aging and can be purchased as a supplement. IGF-1's production is induced by GH and, like GH, IGF-1's levels decline with age and, in mice, low levels of IGF-1 appear to correlate with longevity; mutations in mice that lower IGF-1 seem to extend lifespan, as detailed elsewhere. So, just like for hGH, IGF-1 injections could be counter-productive. In fact, there is some evidence that little people with low levels of IGF-1 live longer. Interestingly, anti-aging therapies based on lowering IGF-1 may be possible. As mentioned elsewhere, IGF-1 does appear to play a role in aging, but whether it can be used in anti-aging is pure speculation at this stage. Clearly, however, IGF-1 injections are unlikely to extend lifespan and, like hGH, may even be harmful.
Other hormones whose production decreases with age include DHEA and melatonin. DHEA has been reported to improve the wellbeing of the elderly by a variety of ways: improved memory, immune system, muscle mass, sexual appetite, and benefits to the skin. Protection against cancer has also been argued but there is really no strong scientific evidence for this. Minor side effects such as acne have also been reported. One clinical study in elderly women found no evidence of benefits from DHEA .
Melatonin is a hormone mostly involved in sleep and circadian rhythms, the latter hypothesized by some to be associated with aging and life-extension. It appears to have antioxidant functions--more about antioxidants below--in the brain and may have some beneficial effects in elderly patients in particular in terms of sleep. Some of its proponents claim it delays the aging process and many age-related diseases, though this is far from proven. In mice, melatonin can increase lifespan but also appears to increase cancer incidence. In humans there is no data to determine whether melatonin extends longevity, though it might have benefits in some patients. Although it can be used for jet lag and some sleep disorders, it may also cause sleep disorders such as nightmares and vivid dreams. One study claimed that melatonin levels do not decrease with age, except maybe at night, although due to diseases or drugs elderly persons can have low levels of melatonin. Melatonin may also aggravate asthma.
Finally, for women, estrogen is a popular anti-aging therapy. This hormone is generally used in conjunction with others in hormone replacement therapy. It does appear to reduce some of the effects of menopause by protecting against heart disease and osteoporosis. On the other hand, it could increase risk of breast cancer and may lead to weight gain and thrombosis as side effects. There is a vast literature on the advantages and disadvantages of hormone replacement therapy, though this is outside the scope of senescence.info. In the context of aging, there is no evidence that estrogen is a viable anti-aging therapy. For men, testosterone has also been touted as anti-aging but, again, there is no evidence it has anti-aging benefits even if it might have some benefits like, say, increased sexual function and muscle mass.
Studies in mice do not by and large suggest a beneficial role for GH. If any, they suggest a harmful role. Though one study found that a low-dose GH therapy increases lifespan in aged mice, mice genetically modified to produce lots of GH live less than controls while mice producing less GH live longer. Of course, as mentioned above, studies in animals are not always relevant to human biology. Nonetheless, the results in mice suggest that higher GH levels will not make you live longer. Studies in humans with a deficiency in GH signalling due to a defect in the GH receptor also suggest a strong cancer protection due to decreased GH signalling. The human studies also hint at a sort of supernova effect: hGH makes patients feel better but might actually diminish their lifespan. In conclusion, hGH might be useful in certain aged patients, for example its use has been suggested in cases of depression, but by and large it should be seen as cocaine for granddad. Lastly, I should point out that there are (young) patients with GH deficiency that if untreated have a reduced longevity, so hGH does have clinical applications.
Insulin-like growth factor 1 (IGF-1) is another hormone that may play a role in aging and can be purchased as a supplement. IGF-1's production is induced by GH and, like GH, IGF-1's levels decline with age and, in mice, low levels of IGF-1 appear to correlate with longevity; mutations in mice that lower IGF-1 seem to extend lifespan, as detailed elsewhere. So, just like for hGH, IGF-1 injections could be counter-productive. In fact, there is some evidence that little people with low levels of IGF-1 live longer. Interestingly, anti-aging therapies based on lowering IGF-1 may be possible. As mentioned elsewhere, IGF-1 does appear to play a role in aging, but whether it can be used in anti-aging is pure speculation at this stage. Clearly, however, IGF-1 injections are unlikely to extend lifespan and, like hGH, may even be harmful.
Other hormones whose production decreases with age include DHEA and melatonin. DHEA has been reported to improve the wellbeing of the elderly by a variety of ways: improved memory, immune system, muscle mass, sexual appetite, and benefits to the skin. Protection against cancer has also been argued but there is really no strong scientific evidence for this. Minor side effects such as acne have also been reported. One clinical study in elderly women found no evidence of benefits from DHEA .
Melatonin is a hormone mostly involved in sleep and circadian rhythms, the latter hypothesized by some to be associated with aging and life-extension. It appears to have antioxidant functions--more about antioxidants below--in the brain and may have some beneficial effects in elderly patients in particular in terms of sleep. Some of its proponents claim it delays the aging process and many age-related diseases, though this is far from proven. In mice, melatonin can increase lifespan but also appears to increase cancer incidence. In humans there is no data to determine whether melatonin extends longevity, though it might have benefits in some patients. Although it can be used for jet lag and some sleep disorders, it may also cause sleep disorders such as nightmares and vivid dreams. One study claimed that melatonin levels do not decrease with age, except maybe at night, although due to diseases or drugs elderly persons can have low levels of melatonin. Melatonin may also aggravate asthma.
Finally, for women, estrogen is a popular anti-aging therapy. This hormone is generally used in conjunction with others in hormone replacement therapy. It does appear to reduce some of the effects of menopause by protecting against heart disease and osteoporosis. On the other hand, it could increase risk of breast cancer and may lead to weight gain and thrombosis as side effects. There is a vast literature on the advantages and disadvantages of hormone replacement therapy, though this is outside the scope of senescence.info. In the context of aging, there is no evidence that estrogen is a viable anti-aging therapy. For men, testosterone has also been touted as anti-aging but, again, there is no evidence it has anti-aging benefits even if it might have some benefits like, say, increased sexual function and muscle mass.
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