General Description
Wild yam (also known as colic root, devil's bones, rheumatism root,
or yuma) is a perennial vine found in open woods and moist thickets
throughout much of the eastern United States. The plant has a woolly
reddish-brown stem, which grows from 1 to 6 meters long, and broad,
ovate leaves, which are 5 to 15 centimeters long and about three-fourths
as wide. Wild yam flowers in June and July, bearing small, greenish-yellow
blossoms, which eventually produce three-winged capsules containing
winged seeds. The plant has a slender, knotty, matted, tuberous
rootstock, which is used medicinally.1
Health Applications
- Menopause
- Cramps
- Premenstrual syndrome
- Morning sickness
History and Traditional Use
While the medicinal use of other yam species dates back over 2,000
years, the "discovery" of wild yam was relatively recent. Dr. Bone,
a Hessian mercenary and physician who settled in New Jersey after
the American Revolution, is reported to have used wild yam root
to treat "bilious colic" in the latter part of the 18th Century.
Prior to that, the root was primarily used in poultices to treat
wounds.2 Steroidal sapogenins found in several
yam species have been used in the production of oral contraceptives
and synthetic hormones (such as progesterone, corticosteroids, estrogens,
androgens, and other sex hormones) since 1940.2
In recent years, wild yam root has become popular for treatment
of menopausal symptoms, premenstrual syndrome (PMS), and abdominal
cramps; however, there is little scientific evidence to support
such use.
Chemical Composition
Wild yam contains steroidal sapogenins (most notably diosgenin)
and alkaloids. Wild yam extracts are often standardized to provide
consistent diosgenin levels.
Wild Yam and Hormones
Much of the popular use of wild yam is based on the erroneous
belief that diosgenin can act as a precursor for DHEA, progesterone,
and other steroid hormones. Pharmaceutical hormones are made from
diosgenin through a chemical conversion process. This chemical
synthesis does not occur in the body.2,3 There
is no scientific evidence that the use of wild yam can influence
hormonal levels or alleviate symptoms associated with PMS or menopause.
Dosage/Toxicity
Wild yam root is commonly taken in doses of 1,000 mg per day,
and there are no known side effects at this dosage range. Topical
creams containing wild yam can be applied liberally with no adverse
effects, with the possible exception of allergic reactions in
some individuals. Wild yam contains alkaloids which are poisonous
in large doses;4 however, there are no known
cases of wild yam toxicity. |
