wild yam (generic name)
an herbal product - treats High cholesterol, Menopausal symptoms, and Hormonal properties
Table of Contents
Top Learning Centers(Recursos en Español)
Alternate TitleDioscorea villosa L., Yam
CategoryHerbs & Supplements
Atlantic yam, barbasco, batata silvestre, black yam, China root, colic root, devil's bones, Dioscorea, Dioscorea barbasco, Dioscorea hypoglauca, Dioscorea macrostachya, Dioscorea opposita, Dioscorea villosa, Dioscoreae (family), diosgenin, Mexican yam, natural DHEA, phytoestrogen, potassium, rheumatism root, shan yao, white yam, wild yam root, yam, yellow yam, yuma.
Note: "Yams" sold in the supermarket are members of the sweet potato family and are not true yams.
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.
EvidenceDISCLAIMER: These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Animal studies have shown that wild yam can reduce the absorption of cholesterol from the gut. Early studies in humans have shown changes in the levels of certain sub-types of cholesterol, including decreases in low-density lipoprotein (LDL, or "bad cholesterol") and triglycerides and increases in high-density lipoprotein (HDL, or "good cholesterol"). However, no changes in the total amount of blood cholesterol have been found. More studies are needed in this area.
Most studies have not shown a benefit from wild yam given by mouth or used as a vaginal cream in reducing menopausal symptoms. However, replacing two thirds of staple food with yam for 30 days was shown to improve the status of sex hormones, lipids, and antioxidants in a recent study in postmenopausal women. The authors suggest that these effects might reduce the risk of breast cancer and cardiovascular diseases in postmenopausal women. Further research is needed before a recommendation can be made.
Hormonal properties (to mimic estrogen, progesterone, or DHEA):
Despite popular belief, no natural progestins, estrogens, or other reproductive hormones are found in wild yam. Its active ingredient, diosgenin, is not converted to hormones in the human body. Artificial progesterone has been added to some wild yam products. The belief that there are hormones in wild yam may be due to the historical fact that progesterone, androgens, and cortisone were chemically manufactured from Mexican wild yam in the 1960s.
TraditionWARNING: DISCLAIMER: The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.
Antifungal, anti-inflammatory, antiviral, asthma, bile flow improvement, biliary colic, breast cancer, breast enlargement, cancer prevention, cardiovascular disease, carminative (prevents gas), childbirth, cramps, croup, decreased perspiration, diverticulitis, energy improvement, excessive perspiration, expectorant, intestinal spasm, irritable bowel syndrome, joint pain, libido, liver protection, low blood sugar, menstrual pain or irregularities, morning sickness, nerve pain, osteoporosis, pancreatic enzyme inhibitor, pelvic cramps, postmenopausal vaginal dryness, premenstrual syndrome (PMS), rash, rheumatic pain, spasms, urinary tract disorders, uterus contraction, vomiting.
Adults (18 years and older)
There are no proven effective medicinal doses for wild yam.
Children (younger than 18 years)
Not enough evidence is available to recommend use in children.
SafetyDISCLAIMER: Many complementary techniques are practiced by healthcare professionals with formal training, in accordance with the standards of national organizations. However, this is not universally the case, and adverse effects are possible. Due to limited research, in some cases only limited safety information is available.
Rubbing the skin with Dioscorea batatas (a yam species related to Dioscorea villosa) has been reported to cause allergic rash. Workers exposed to Dioscorea batatas in large amounts and for a prolonged time have developed asthma that is made worse by exposure to the yam. A person who is known to have an allergy to Dioscorea batatas may also be allergic to other Dioscorea types.
Side Effects and Warnings
Rubbing the skin with Dioscorea batatas, a related yam species, has been reported to cause a rash at the site of contact. Wild yam cream caused no rash in 23 healthy women in one reported study. In another study, wild yam given by mouth was reported to cause stomach upset at high doses.
Wild yam was believed in the past to have properties similar to the reproductive hormone progesterone, but this has not been supported by scientific studies. It has been suggested that some wild yam creams might be tainted with artificial progesterone. Based on theoretical hormonal properties and possible progesterone contamination, people with hormone-sensitive conditions should use wild yam products with caution. This caution applies to people who have had blood clots or strokes and to women who take hormone replacement therapy or birth control pills. In addition, women with fibroids, endometriosis, or cancer of the breast, uterus, or ovary should be aware that these are hormone-sensitive conditions that may be affected by agents with hormonal properties.
Caution is advised in patients with diabetes or low blood sugar and in those taking drugs, herbs, or supplements that affect blood sugar. Blood sugar levels may need to be monitored by a healthcare provider and medication adjustments may be necessary.
Pregnancy & Breastfeeding
Use of wild yam is not recommended during pregnancy or breastfeeding due to a lack of safety information. Wild yam is believed to cause uterine contractions and therefore use is discouraged during pregnancy. Wild yam was once thought to have effects similar to those of reproductive hormones, although this has not been proven in scientific studies. Artificial progesterone may be added to some products.