To anyone over the age of 40, DHEA certainly sounds alluring. As a supplement, it's been touted to slow aging, burn fat, build muscle, fight depression, improve sexual function, and increase memory. And the supposed miracles don't stop there. Proponents claim that DHEA can ward off cancer and heart disease, and even cure Parkinson's disease. So what's not to like about it?

Don't start popping those pills just yet. There's no proof behind any of these claims, and experts worry that DHEA (dehydroepiandrosterone) may do more harm than good. Until long-term clinical trials provide more definitive answers, both the Mayo Clinic and the National Institute on Aging (NIA) are recommending that people not use DHEA as an "anti-aging" supplement.

As for the bold claims, because DHEA is sold as a dietary supplement, it is neither regulated nor approved by the Food and Drug Administration for any medical or nutritional use. Dr. Frank Bellino, endocrinology program administrator at the NIA, points out that "there is no really good evidence yet that DHEA has much of a beneficial effect in people, so it's probably a waste of money to use it."

In fact, warns Dr. Bellino, DHEA "has some potential for doing harm, particularly at high levels and for long periods of time."

A growing concern

A naturally occurring hormone manufactured by the adrenal gland, DHEA is most abundant in the body around age 30; then it drops off gradually, finally reaching very low levels in old age.

Concerns about DHEA have to do with the important role hormones play in the body, since the body converts DHEA into the potent sex hormones estrogen and testosterone. Even tiny amounts of DHEA or supplemental hormones can have far-reaching effects on the functioning of organs and tissues. Research has shown that the higher your hormone levels are, the greater your chances of experiencing negative effects.

Scientists already know that testosterone plays a role in prostate cancer and that high levels of naturally produced estrogen may increase a woman's risk of breast cancer. Researchers are concerned that higher levels of sex hormones caused by using DHEA might actually promote those diseases, as well as other conditions in women, such as menstrual irregularities and facial hair growth. And despite claims to the contrary, DHEA may increase the risk of heart disease and cause liver damage and mood changes.

Why the hype?

Is there any good news about DHEA? Although animal research has shown that DHEA may help prevent some types of cancer and boost the immune system, and some research on humans has linked DHEA use with increased muscle mass and improved libido, test results on people have been decidedly underwhelming. "DHEA appears to do amazing things for rats and mice, but not a heck of a lot for people," explains Dr. Bellino. "The biology of DHEA is very different in rodents and primates, which may explain the difference." Furthermore, according to Bellino, positive results in humans, such as prevention of bone loss or decreased fat mass, could simply be explained by the conversion of DHEA into estrogen and testosterone -- rather than by DHEA itself.

Clinical trials underway on DHEA should shed some light on the supplement's value. Research sponsored by the National Institute of Mental Health is studying the impact of DHEA on mood disorders. Another study is examining the impact of combined estrogen and DHEA supplementation on muscle mass, strength, and endurance in menopausal women. DHEA is also being looked at as a treatment for lupus and autoimmune disease.

Until the mystery surrounding DHEA gets cleared up, however, most experts agree that using DHEA is simply not worth the risk. Naturally declining levels of DHEA are not known to cause any disease, and according to the Mayo Clinic, no known drug, pill, or treatment has been proven to reverse the aging process or to extend life. If you have questions about DHEA, consult a medical professional.

If you're concerned about growing old, don't despair. According to Dr. Bellino, there are plenty of safe, simple things you can do to promote longevity and improve the quality of your later years: "Read, think, eat a moderate- to low-fat diet, exercise, perhaps take antioxidants. There's no magic pill. At least not yet!"

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Outside link: Information about DHEA from the National Institute on Aging