Wild Yam (Dioscorea villosa) information

Source:
Wild Yam (Dioscorea villosa) - is a perennial climbing vine common in the eastern and central United States. The vine is commonly seen twining in hedges, and over bushes and fences. Wild Yam can grow to a length of 15 feet or more with a smooth, reddish-brown stem sporting heart-shaped 2 – 6 inch long and 1 to 4 inches wide leaves. The leaves have very prominent veins, which run lengthwise from the center top of the heart shape out into a fan pattern. The root runs horizontally beneath the surface of the ground, and is long and branched. The small, greenish-yellow flowers are produced in drooping clusters about 3 to 6 inches long (male) and in drooping, spikelike heads (female), blooming from June to August.


Traditional uses:
Wild Yam has been been prescribed over the years for the following conditions:

  • Premenstrual Pain – traditionally used for menstrual cramps, although the active ingredient in Wild Yam, Diosgenin, cannot be converted into progesterone in the body, the herb still plays an important role in the regulation of progesterone.
  • Antispasmodic – eases discomfort from colic.
  • Anti-inflammatory - use to ease the pain secondary to rheumatoid arthritis.
  • Claudication - (pain in the lower extremities caused by spasms in the blood vessels supplying the leg muscles) – antispasmodic qualities relieves the pain of claudication.
  • Relieves cough - Mucilage is a thick, slimy substance produced by the herb. Mucilage has a soothing effect on mucous membranes, such as the tissues that line the respiratory passages. Chinese yam contains large amounts of mucilage.

Physiology:
The tubers, or fleshy, root-like parts, of wild yams (not to be confused with the sweet potato yam) contain Diosgenin, a steroid-like substance that can be converted into the female hormone progesterone. Diosgenin has served a key role in the synthesis of hormones and the development of the birth control pill, representing one of the major advances in plant medicine. When there is a lack of progesterone in your body, you'll likely experience mood swings, irritability, anger, depression, headaches, loss of sexual desire and even weight gain. Progesterone is also responsible for naturally balancing estrogen, the second major female hormone. Many women have excess estrogen, which increases the risk of breast cancer, cancer of the uterus, and osteoporosis. Excess estrogen can also severely worsen premenstrual syndrome (PMS). To balance progesterone/estrogen levels, many doctors prescribe synthetic progesterone, progestin, which has recognized side effects. The natural progesterone's side effects are minimal.

Regulating the delicate balance of progesterone and estrogen in the system, increasing progesterone has the following positive effects:

  • Maintains increased libido (sex drive)
  • Promotes fat burning for energy (thermogenesis)
  • Promotes bone building and protects against osteoporosis
  • Maintains lining of the uterus
  • Helps protect against breast cancer
  • Protects against fibrocystic breasts
  • Natural diuretic thus helping to control fluid balance
  • Acts as a natural anti-depressant
  • Aids thyroid hormone action
  • Normalizes blood clotting
  • Keeps blood sugar levels normal
  • Normalizes zinc and copper levels
  • Promotes proper cell oxygen levels for enhanced energy
  • Protects against endometrial cancer

Clinical Studies:
Research studies have shown that the steroidal saponins (i.e. disogenin) are responsible for some of the activity of Wild yam. Animal studies have shown that another compound, dioscoretine, is responsible for lowering blood glucose levels. Extracts from Wild yam have also been shown in clinical studies to increase the level of HDL cholesterol, which is known as the "good" cholesterol because a high level of HDL cholesterol seems to protect against heart attack. Medical experts think that HDL tends to carry cholesterol away from the arteries and back to the liver, where it is passed from the body. Some experts believe that excess cholesterol is removed from atherosclerotic plaque by HDL, thus slowing the build-up. Iwu MM, Okunji CO, Ohiaeri GO, et al. Hypoglycaemic activity of dioscoretine from tubers of Dioscorea dumetorum in normal and alloxan diabetic rabbits. Planta Med 1990;56:264–7., Araghiniknam M, Chung S, Nelson-White T, et al. Antioxidant activity of dioscorea and dehydroepiandrosterone (DHEA) in older humans. Life Sci 1996;11:147–57.

Modern day uses:
Today, physicians and herbal specialist prescribe Wild yam for the following health benefits:

  • Balancing of female hormones
  • Increasing sex drive
  • Antioxidant activity
  • Reducing harmful cholesterol levels
  • Decreasing blood glucose levels
  • Menstrual cramps
  • Nausea
  • Reducing inflammation e.g. Rheumatoid arthritis
  • Gallbladder colic

Precautions and/or adverse effects:
Individuals with preexisting medical conditions should consult with their physician particularly if they are taking prescription or over-the-counter-medications or supplements. Women who are pregnant or nursing and children should also consult with their physician prior to taking any new supplements. There are very few side effects associated with Wild Yam. Some individuals may experience nausea when taking large amounts of the herb. An animal study indicated that the active component of wild yam, diosgenin, may interact with estradiol (return to homepage).