Will natural yam extract pills increase my DHEA levels?
Most of the DHEA sold now in vitamin stores, drug stores or through mail order firms is produced in a laboratory from diosgenin. However, some vitamin companies do sell extracts of wild yams in pill form, without first processing it into DHEA. Some even promote these yam-extract products as "DHEA precursor complexes" or "natural DHEA."

To get to the bottom of the yam-extract conversion issue, I spoke with a leading expert in the field, Seymour Lieberman, Ph.D., from St. Luke's-Roosevelt Hospital Center, New York. Dr. Lieberman has been studying DHEA (which he calls 'dehydro') and other steroids longer than most researchers in the field (55 years so far!). He is one of the top experts in the world on the biochemical aspects of DHEA.

Sahelian: Congratulations on publishing such a detailed and thorough article on the metabolism of DHEA and other steroids in the Annals of the New York Academy of Sciences.

Lieberman: Thank you. Dehydro is my favorite topic. It's a fascinating compound and we only know a fraction of what we need to know.

Sahelian: Some vitamin stores sell wild yam extracts. There are claims that these yams have compounds which can be converted into DHEA by the body. Is this possible?

Lieberman: DHEA is made commercially from a plant of the Dioscorea family [wild yams] found in abundance in Mexico. Extracts of this plant contain a steroidal saponin [called diosgenin] which may be converted in a laboratory by a series of 6 to 8 chemical reactions into DHEA. A comparable series of reactions is not known to exist in nature and certainly not in humans. Consequently it is highly unlikely, perhaps impossible is a better word, that the ingestion of extracts of the Dioscorea plant will lead to the formation, by metabolic transformation of the relevant plant constituent, to either pregnenolone or DHEA.

In a word, Dr. Lieberman means "No."

Do animals also make DHEA?
Significant amounts of DHEA are made only by humans and primates, such as apes, gorillas, and monkeys. Rodents, such as mice or rats, have only small amounts circulating in their bloodstream. DHEA administration in rodents has often shown beneficial effects, but many researchers caution about making health claims for humans based solely on rodent studies.

What can I do to keep my DHEA(S) level up?
Leading a relaxed lifestyle with high psychological well-being (easier said than done) can help you live longer and maintain optimal DHEAS levels. Chronic stress can decrease DHEAS levels (Labbate, 1995). As to the role of exercise, one study did not find an association. Ninety-six patients with coronary artery disease were started on an exercise program and had their DHEAS levels measured. After 12 weeks, there was no change in the levels of this hormone (Milani, 1995). The researchers conclude, "Although behavior therapy in combination with exercise training was previously shown to lead to increase in DHEAS, exercise training alone has no significant impact on DHEAS, thereby strengthening the suggested role of behavioral changes in modifying this hormone."

Is it okay if I self-medicate with DHEA?
I recommend that you see a health care practitioner who is familiar with the use of this hormone before taking it for prolonged periods.