A hormone made in the adrenal glands, dehydroepiandrosterone (DHEA) also forms the basis of the sex hormones, estrogen and testosterone. DHEA production is highest in the 20s and starts to taper off thereafter. By age 70, DHEA levels are only about 20 percent of what they were in a person's youth. This has led some researchers to believe that low DHEA levels may be associated with many age-related disorders, including loss of muscle mass, memory and bone density. Study results on DHEA supplementation are conflicting, with some positive benefits seen in the areas of depression, adrenal insufficiency and lupus.
In some countries DHEA is available as a dietary supplement and is sold over-the-counter. Elsewhere, it can only be acquired by prescription. It is widely promoted as a way to combat the effects of aging, but clinical studies generally do not support most of these claims for DHEA. Supplementation was found to raise blood levels of DHEA in some anti-aging studies, but no corresponding improvements in age-related conditions were seen.
DHEA acts as a cortisol-antagonist. It counteracts the effects of cortisol, a stress hormone produced by the adrenal gland. This hormone is partially responsible for the flight-or-flight effect and causes a rise in blood sugar and blood pressure while simultaneously suppressing the immune system and bone formation. Excessive and prolonged stress causes chronically elevated levels of cortisol. This, in turn, leads to blood sugar imbalances, decreased bone density and muscle mass, accumulation of abdominal fat, and impaired mental functioning.
Low DHEA levels have been found to correspond to high levels of cortisol, while high DHEA levels correlate to low cortisol levels. This antagonistic relationship with cortisol is an evolving area of depression research. Studies show that DHEA seems to alleviate mild to moderate depression symptoms in some patients. There is also evidence that DHEA may help with anxiety. DHEA is believed to be neurologically active and may stimulate an increase in the neurotransmitter serotonin.
Research has discovered low DHEA levels in patients suffering from severe kidney disease, Type 2 diabetes, AIDS, decreased adrenal functioning and other chronic illnesses. Some research shows positive results using DHEA to treat adrenal insufficiency and lupus. There has also been research that supports using DHEA for obesity.
Despite DHEA's promotion for certain purposes, studies on its effects have been inconclusive or show no benefits for a variety of conditions. The results of bone density, chronic fatigue syndrome, and sexual functioning studies are unclear. Preliminary studies have shown DHEA to have some benefit for schizophrenia and as a topical application to treat aging skin, but further testing is required to confirm the initial findings. No benefits have been found for increasing muscle strength, memory or immune functioning.
Potential side effects of DHEA supplementation include lower levels of high-density lipoprotein (HDL), considered the good cholesterol, an increase in facial hair in females, and the development of acne. Research continues on the effects of prolonged use of the hormone, as there is a suspected link between DHEA supplementation and liver damage. It may also cause an increased risk of certain hormone-sensitive cancers. In addition, supplementing with DHEA may further decrease the body's own production of the hormone.