The genus Dioscorea of the family Dioscoreaceae includes more than 850 species of annual, twining, tuberous vines found in tropical and warmer temperate climates. Collectively, those species with edible roots are known as "yams." Some species with starchy fleshy tubers have been eaten as food. Others have been collected for their glycosides, particularly botogenin and diosgenin, whose steroidal nucleus is altered in the laboratory to produce numerous steroid hormones. The richest source of steroidal precursors is D. floribunda M. Martens and Galeotti, native to Mexico. D. composita Hemsl., also from Mexico, has served as a primary source of Mexican yam. The so-called "wild yam," D. villosa L., best known historically as "colic root" is an herbaceous vine of rich open woods and moist thickets from Connecticut and New York, south to Florida, west to Texas and Minnesota. D. quaternata (Walter) J. F. Gmelin has a similar range and is separated on technical details. It is unlikely that they are distinguished by wild collectors of the roots.
Diosgenin was first isolated from Dioscorea by Japanese researchers in 1936. Conversion of this steroidal sapogenin to progesterone first occurred in 1940. In the decades that followed, diosgenin and botogenin served as the major commercial precursors for the manufacture of steroid medications, including oral contraceptives, topical hormones, systemic corticosteroids, androgens, estrogens, progestogens, and other sex hormones. Indirectly, Dioscorea species have quietly had a greater impact on twentieth-century social and medical practices than any other plant group.
In recent years, numerous "wild yam" and "Mexican wild yam" products, including both oral and topical dosage forms have appeared in the market. At least one multilevel company has promoted wild yam as a "natural precursor" to the hormone DHEA, claiming that diosgenin is converted by the body into this hormone. Of course, no scientific evidence is available to support this wishful thinking. Other promoters claim that application of a wild yam cream to the skin magically transforms disogenin into progesterone in the body. Some products add "natural" progesterone in an attempt to "deliver the goods." All of this is offered to reverse aging, treat menopausal and menstrual symptoms, and cure osteoporosis, to name just a few purported uses! According to one promotional brochure, "the Mexican yam," Dioscorea villosa, was first mentioned by the Chinese in 25 B.C.! How interesting that the Chinese supposedly knew, at this early date, about a so-called Mexican plant that does not even occur in Mexico.
Although diosgenin can be converted in the laboratory to numerous steroidal compounds, that chemical synthesis cannot and does not occur in the human body. The 1990s' wild yam scam is a sign of the urgent need for better self-regulation by the herb industry, to say nothing of more active federal regulators.
Wild yam was until 1970 the sole source of the hormone material diosgenin, used in the contraceptive pill and other steroid hormones. This would suggest that wild yam has a significant effect on the balance of the female hormones. Wild yam was traditionally used for easing menstrual cramps and, because of its antispasmodic action, can be used for any kind of muscular spasm and colic, such as intestinal and bilious colic, flatulence, ovarian and uterine pain. The steroidal saponins are also anti-inflammatory, making it a useful herb when treating rheumatoid arthritis and inflammatory conditions of the bowel. Its diuretic effect, combined with the antispasmodic action, soothes painful conditions of the urinary tract.
In all areas of the body, it seems best adapted to irritable and excitable conditions, and less efficient when due to lack of tone. This applies particularly to pregnancy and childbirth. Wild yam has been used for any kind of cramping in pregnancy, particularly when it is related to stress and tension. Wild yam has also been used traditionally in threatened miscarriage. Wild yam has also been used with effect in nausea in pregnancy.
Root and rhizome.
Traditional uses - Both the Maya and the Aztec peoples used wild yam medicinally possibly to relieve pain. Wild yam is also known as colic root and rheumatism root in North America, indicating its use by European settlers for these conditions.
Gynecological problems - In North and Central America, wild yam is a traditional relaxing remedy for painful menstruation, ovarian pain; and labor.
Arthritis & rheumatism - The herb's combination of anti-inflammatory and antispasmodic actions makes it extremely useful in treatments for arthritis and rheumatism. Wild yam reduces inflammation and pain, and relaxes stiff muscles in the affected area.
Muscle spasms & pain - Wild yam helps to relieve cramps, muscle tension, and colic.
Digestive problems - Wild yam can be an effective treatment for digestive problems, including gallbladder inflammation, irritable bowel syndrome, and diverticulitis.