Zedoary (e zhu)

What is zedoary? What is it used for?

Zedoary is related to the turmeric family. Native to India, it was introduced to Europe and eastern Asia several centuries ago. Originally used as a type of spice, it has been replaced by ginger in most cultures. Nevertheless, it remains an important component of many herbal preparations.

The medicinal part of zedoary is its rhizome, a fleshy stem that grows underground. The rhizome has a brown skin and a bright orange, hard interior, similar to a mango. The rhizomes are dug in the autumn and winter. They are cleaned (any fibrous roots attached to the rhizome are removed), boiled and dried, then cut up into slices.

Zedoary has bitter and pungent properties in traditional Chinese medicine, and is affiliated with the Liver and Spleen meridians. Its main functions are to invigorate blood and move stagnation, and to promote the circulation of qi; it stimulates production of digestive juices, improves the flow of bile into the digestive tract, and combats digestive spasms and upset stomach. It is often used to treat qi and blood stagnation, which may manifest as abdominal pain, abdominal distention or amenorrhea. Zedoary is sometimes used in combination with other herbs, such as costus, hawthorn and bitter orange.

How much zedoary should I take?

The typical recommended dose of zedoary is between 3 and 10 grams, depending on the condition being treated. Many practitioners recommend a form of zedoary tea, which is made by taking 1 to 1.5 grams of crushed or powdered zedoary along with a cup of boiling water. Zedoary tea is usually taken with meals, or just before eating.

What forms of zedoary are available?

Zedoary is available in two common forms - as a powder (which can be found in many herbal shops), or sliced and dried (which can be found at some Asian markets). Dried zedoary is ground down to a powder and should be stored in an airtight container.

What can happen if I take too much zedoary? Are there any interactions I should be aware of? What precautions should I take?

Because zedoary helps promote the circulation of blood, it should not be used women during menstruation; it also should not be used by women who are pregnant or breastfeeding. Patients on blood-thinning medications or blood pressure medications should also speak with a health care provider before taking zedoary. As always, make sure to consult with a licensed health care practitioner before taking zedoary or any other dietary supplement or herbal remedy.

References

• Heal C, Allsop C. Cooking With Spices. Vermong: David & Charles, 1983.
• Hong CH, Kim Y, Lee SK. Sesquiterpenoids from the rhizome of curcuma zedoaria. Arch Pharm Res October 2001;24(5):424-6.
• Stuart M. The Encyclopedia of Herbs and Herbalism. Turin, Italy: Macdonald and Company, 1987.
• Watanabe K, Shibata M, Yano S, et al. Antiulcer activity of extracts and isolated compounds from zedoary (gajutsu) cultivated in Yakushima (Japan). Yagugaku Zasshi December 1986;106(2):1137-42. In Japanese.
• Yoshioka T, Fujii E, Endo M, et al. Anti-inflammatory potency of dehydrocurdione, a zedoary-derived sesquiterpene. Inflamm Res December 1998;47(12):476-81.