Dehydroepiandrosterone(DHEA)
Dehydroepiandrosterone (DHEA) is the most abundant androgen (male steroid hormone) secreted by the adrenal glands (small hormone producing glands which sit on top of the kidneys), and to a lesser extent, by the ovaries and testes. DHEA can also be converted into other steroid hormones, including testosterone and estrogen. Considerable interest in DHEA has developed in recent years with reports that it may play a role in the aging process. Circulating levels of DHEA peak at age 25 and then steadily decline with age. DHEA levels in 70-year-old individuals tend to be roughly 80 percent lower than those in young adults.
Some researchers consider DHEA a possible anti-aging hormone because DHEA deficiencies in older individuals have been associated with a number of medical conditions including breast cancer, cardiovascular disease, impaired memory and mental function, and osteoporosis. In addition, population-based studies have suggested that people with higher DHEA levels tend to live longer, healthier lives than those with lower levels of DHEA. However, low levels of DHEA being linked to certain diseases does not necessarily mean that DHEA supplements will reduce the risk or improve the outcome of these conditions.
The United States Food and Drug Administration (FDA) removed DHEA supplements from the market in 1985 due to false claims about health benefits. However, since the passing of the US Dietary Supplement Health and Education Act of 1994, DHEA has made its way back on the market and its popularity continues to grow. Despite this growth and attention, support for the health claims, particularly as tested on people, is lacking. Plus, given that DHEA products are sold as dietary supplements, there is no control over their contents or the manufacturing practices of the companies that make the supplements. One independent evaluation found that the amount of DHEA in over the counter products ranged from 0% to 150% of what the content stated on the label.
Aging
Given that DHEA levels decline with advancing age, some researchers have investigated whether DHEA supplementation may slow or prevent age-related declines in mental and physical function. Preliminary results from the DHEAge study in France suggest that the hormone may slow bone loss, improve skin health, and enhance sexual drive in aging adults, particularly women older than 70 years of age. Animal studies that have shown a boost in memory for older rats taking DHEA supplements. Results from human studies, however, have been conflicting. Some studies have shown that DHEA improves learning and memory in those with low DHEA levels, but other studies have failed to detect any significant cognitive effects fro; DHEA supplementation. Further studies are needed to determine whether DHEA supplementation helps prevent or slow medical conditions associated with the aging process.
Adrenal Insufficiency
As mentioned earlier, DHEA is one of the hormones made in the adrenal glands. When the adrenal glands do not make enough hormones, this is called adrenal insufficiency. Women with this condition who were given DHEA supplements reported improved sexuality and sense of well-being (including decreased feelings of depression and anxiety). Only a doctor can determine if you have adrenal insufficiency and if DHEA, along with other hormones, is needed. Adrenal insufficiency can be a medical emergency, particularly when first diagnosed. This is especially the case if your blood pressure is low, which can cause you to experience dizziness or lightheadedness. Another reason to seek medical attention right away in the case of adrenal insufficiency is swelling of the ankles or legs.
Impotence
Studies suggest that DHEA supplementation may help impotent men have and sustain an erection.
Osteoporosis
Studies have shown that DHEA cream applied to the inner thigh may boost bone density in older women.
Anorexia Nervosa
Women with anorexia nervosa are at increased risk for bone fractures and can develop osteoporosis at a younger age than women without eating disorders. It has been observed that adolescents and young adults with anorexia nervosa tend to have low levels of DHEA. Some studies suggest that DHEA may help protect against bone loss in people who are anorexic.
Athletic Performance
Although DHEA supplements are widely used by athletes and body builders to boost muscle mass and burn fat, there is little evidence to support these claims. There are no published studies of the long-term effects of taking DHEA, particularly in the large doses used by athletes. Plus, the building blocks of testosterone, including DHEA, may adversely affect cholesterol in male athletes by lowering HDL ("good") cholesterol.