Yam

Chinese: 山药

Pinyin: Shān Yào

Parts used: Dried rhizome

TCM category: Tonic herbs for Qi Deficiency

TCM nature: Neutral

TCM taste(s): Sweet

Meridian affinity: SpleenKidneyLung

Scientific name: Dioscorea opposita

Other names: Chinese yam, Cinnamon vine, Nagaimo, Chinese potato, Japanese mountain yam, Korean yam

Use of yam (Shān Yào) in TCM

Please note that you should never self-prescribe TCM ingredients. A TCM ingredient is almost never eaten on its own but as part of a formula containing several ingredients that act together. Please consult a professional TCM practitionner, they will be best able to guide you.

Preparation: Remove impurities, wash, cut and dry.

Dosage: 3-6g.

Main actions according to TCM*: Tonifies the Spleen and Stomach. Tonifies the Lung Qi and nourishes the Lung Yin. Nourishes the Kidneys and consolidates Jing.

Primary conditions or symptoms for which yam may be prescribed by TCM doctors*: Vaginal discharge Diarrhea Spermatorrhea Urinary incontinence Uterine prolapse Whooping cough

Contraindications*: This herb should be used with caution when there is Excess Heat or Dampness, especially Dampness in the abdomen.

Common TCM formulas in which yam are used*:

Key TCM concepts behind yam's properties

In Traditional Chinese Medicine (TCM), yam are plants that belong to the 'Tonic herbs for Qi Deficiency' category. Tonic herbs are used for patterns of Deficiency, when one lacks one of the 'Four Treasures' (Qi, Blood, Yin and Yang). Qi tonics are typically sweet and they tend to enter the Spleen and Lungs because these organs are most involved with the production of Qi.

Furthermore yam are plants that are Neutral in nature. This means that yam typically don't affect the balance in your body. Balance between Yin and Yang is a key health concept in TCM. Eating too many "Hot" (Yang) ingredients can lead to an imbalance whereby one has a Yang excess. The inverse is true as well: too many "Cold" (Yin) ingredients can lead to a Yin excess. The Neutral nature of yam means that you don't have to worry about that!

Yam also taste Sweet. The so-called "five elements" theory in Chinese Medicine states that the taste of TCM ingredients is a key determinant of their action in the body. Sweet ingredients like yam tend to slow down acute reactions and detoxify the body. They also have a tonic effect because they replenish Qi and Blood.

The tastes of ingredients in TCM also determine what organs and meridians they target. As such yam are thought to target the Spleen, the Kidney and the Lung. In TCM the Spleen assists with digestion, blood coagulation and fluid metabolism in the body. The Kidneys do not only regulate the urinary system but also play a key role in the reproductive system and the growth and aging process of the body. In addition to performing respiration, the Lungs are thought to be a key part of the production chain for Qi and the body fluids that nourish the body.

Research on yam

A mixture consisting of Rhizoma Dioscoreae has a good nutritional and health promoting effect on pregnancy.1

Sources:

1. Ling CD, Zhang ZJ, Chen ZL. (1996). Studies on nutritional effects of traditional Chinese tonics with strengthened nutrients on pregnant women and rats. Zhongguo Zhong Xi Yi Jie He Za Zhi. , 16(5):270-3.

Use of yam as food

Yam are also eaten as food. It is used as an ingredient in dishes such as Stir-fried Chinese Yam or Sautéed Yam with Soy Sauce.