Chinese yam (dioscorea opposita) is an ornamental vine that is native to Asia. It also grows in North America, but it is not related to the sweet potatoes called yams that are a popular food in North America. Another name for Chinese yam is cinnamon vine. It is also called shan yao.
The roots of Chinese yam contain diosgenin. This chemical is used to produce steroids such as estrogen and progesterone in a laboratory. In its original form, Chinese yam does not contain hormones.
Chinese yam is used in Chinese herbal medicine. It is traditionally used to treat disorders related to the stomach, spleen, lungs, and kidneys.
While the tuber and bulbs of Chinese yam are edible, generally only the tuber is consumed as food.
As an herbal treatment, Chinese yam is used to target the stomach and spleen. It also thought to act on the lung and kidney. It is used to treat:
- poor appetite
- chronic diarrhea
- dry coughs
- frequent urination
Chinese yam contains allantoin. This is a natural compound that can accelerate the growth of healthy tissue and reduce healing time. Topically, Chinese yam is applied to treat ulcers, boils, and abscesses on the skin. Victims of scorpion stings and snakebites can be treated with its leaf juices.
The roots of Chinese yam contain diosgenin. This natural compound is a phytoestrogen, a plant-based estrogen. When processed in a laboratory, diosgenin can be used to manufacture progesterone. In its original form, Chinese yam does not contain progesterone or other human hormones.
People with conditions related to the stomach, spleen, kidneys, lungs, or skin may benefit from Chinese yam.
Consult your healthcare provider before taking Chinese yam or any medication, herb, or supplement. Because Chinese yam may have properties that enable it to act like a mild form of estrogen, it may interact with hormone replacement therapy or birth control pills (University of Maryland Medical Center, 2013).
When large doses of Chinese yam are consumed, nausea, vomiting, and diarrhea can result. Allergic reactions are rare, but can include rashes and asthma.
Women who are pregnant or breastfeeding should not take Chinese yam without first talking to a medical professional.
In its original form, Chinese yam can be eaten fresh or baked, boiled, fried, or mashed. It is also used in soups.
Chinese yam is available as a liquid, in capsules, as a dried root, and as an extract, to be taken orally for therapeutic purposes. Tea can be made from the fluid extracts.
Chinese yam is also administered in creams or gels that are applied directly to the skin. In some cases, these ointments may contain synthetic progesterone, though they may be promoted as containing natural progesterone. Other additions to these compounds can include vitamins, minerals, and other herbs.
Promoters of Chinese yam claim that it can be used as a remedy for many conditions, including:
- hot flashes associated with menopause
- postmenopausal vaginal dryness
- premenstrual syndrome (PMS)
- gallbladder problems
- rheumatoid arthritis
- menstrual disorders
- digestion disorders
- dry or chronic cough
However, there is insufficient evidence to determine the effectiveness of Chinese yam for these uses (MedlinePlus, 2013).
In addition to its potential medicinal properties, Chinese yam is a nutritious food. It consists primarily of water and starch. It is also a source of vitamin B1, vitamin C, mucilage, amylase, amino acids, and glutamine.
Though Chinese yam does not contain estrogen, it has properties that may cause it to act like a mild form of estrogen. Pregnant or breastfeeding women should avoid Chinese yam. People with hormone-sensitize disorders should also avoid Chinese yam. Hormone-sensitive disorders include endometriosis, uterine fibrosis, and cancers of the breast, uterus, or ovaries.
People with a protein S deficiency should avoid Chinese yam. This condition causes an increased risk for forming clots. The estrogen-like properties of Chinese yam may increase the likelihood of developing clots when a protein S deficiency exists.