Background

• It has been hypothesized that wild yam (Dioscorea villosa and other Dioscorea species) possesses dehydroepiandrosterone (DHEA)-like properties and acts as a precursor to human sex hormones such as estrogen and progesterone. Based on this proposed mechanism, extracts of the plant have been used to treat painful menstruation, hot flashes, and headaches associated with menopause. However, these uses are based on a misconception that wild yam contains hormones or hormonal precursors - largely due to the historical fact that progesterone, androgens, and cortisone were chemically manufactured from Mexican wild yam in the 1960s. It is unlikely that this chemical conversion to progesterone occurs in the human body. The hormonal activity of some topical wild yam preparations has been attributed to adulteration with synthetic progesterone by manufacturers, although there is limited evidence in this area.
• The effects of the wild yam saponin constituent "diosgenin" on lipid metabolism are well documented in animal models and are possibly due to impaired intestinal cholesterol absorption. However, its purported hypocholesterolemic effect in humans and the feasibility of long-term use warrant further investigation.
• There are few reported contraindications to the use of wild yam in adults. However, there are no reliable safety or toxicity studies during pregnancy, lactation, or childhood.

References

• Araghiniknam M, Chung S, Nelson-White T, et al. Antioxidant activity of Dioscorea and dehydroepiandrosterone (DHEA) in older humans. Life Sciences 1996;59:L147-L157.
• Hudson t, Standish L, Breed C, et al. Clinical and endocrinological effects of a menopausal botanical formula. Journal of Naturopathic Medicine 1997;7:73-77.
• Komesaroff PA, Black CV, Cable V, et al. Effects of wild yam extract on menopausal symptoms, lipids and sex hormones in healthy menopausal women. Climacteric 2001;4(2):144-150.
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• Kubo Y, Nonaka S, Yoshida H. Allergic contact dermatitis from Dioscorea batatas Decaisne. Contact Dermatitis 1988;18(2):111-112.
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• Ulbricht C, Basch E, Ulbricht C, et al. Wild yam (Dioscoreaceae). J Herb Pharmacother 2003;3(4):77-91.
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• Wu WH, Liu LY, Chung CJ, et al. Estrogenic effect of yam ingestion in healthy postmenopausal women. J Am Coll Nutr 2005;24(4):235-243.
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