Known as “birthwort,” this plant has been used by numerous societies throughout history to assist in childbirth. Image by Chrizz

Aristolochic acid is not a medicine; it is rather a chemical compound found in eighteen herbs, seven of which have been traditionally used in Chinese Medicine.

Since Aristolochic acid was classified in the 20th century as carcinogenic, herbs containing it have been the focus of research, and all herbal medicines containing Aristolochic acid (even in trace amounts) have been banned in the United States since 2001 – what’s the history of this compound in TCM?

Aristolochic Acid in Herbs Used in TCM

TCM and other medical systems have been using herbs containing Aristolochic acid for thousands of years. For example, numerous societies all over the world have used an herb called “birthwort” (Aristolochia clematitis), which contains Aristolochic Acid, to assist in childbirth.

Of the approximately 5,000 herbs and other natural substances used in TCM, seven plants contain Aristolochic acid. It is a minor component, existing in trace amounts, in five of these seven.
The two herbs that contain a high proportion of Aristolochic acid are Guang Fang Ji (Radix Aristolochiae Fangchi) and Guan Mu Tong (Caulis Aristolochiae Manshuriensis).

Most TCM physicians prescribe these herbs very rarely. In their comprehensive work, Chinese Medical Herbology and Pharmacology (2001), Chen and Chen strongly recommend avoiding Guang Fang Ji (Radix Aristolochiae Fangchi) and Guan Mu Tong (Caulis Aristolochiae Manshuriensis) altogether.

The following chart, based on this work, lists the seven herbs used in TCM that contain Aristolochic acid, the amount of the chemical that they contain, and their estimated toxicity:

Chinese name	English name:	Amount of Aristolochic Acid	Estimated Danger of Toxicity
Guang Fang Ji	Radix Aristolochiae Fangchi	High	its use should be avoided (Chen and Chen, p. 310)
Xun Gu Feng	Herba Aristolochiae Mollissimae	Trace	Negligible
Guan Mu Tong	Caulis Aristolochiae Manshuriensis	High	“The use of aristolochia types of Mu Tong is strongly discouraged because of toxicity associated with aristolochic acid,” (Chen and Chen, p. 397).
Xi Xin	Herba Asari	Trace	Negligible
Qing Mu Xiang	Radix Aristolochiae	Trace	Negligible
Tian Xian Teng	Herba Aristolochiae	Trace	Negligible
Ma Dou Ling	Fructus Aristolochiae	Trace	Negligible

The Use of Herbs Containing Aristolochic Acid in TCM

Shay Ravid, TCM practitioner and lecturer at the Tao College of Traditional Chinese Medicine (Israel), told Decoded Science that, of the 5,000 herbs, minerals and animal substances employed in TCM, only about 500-600 are used on a regular basis. The rest –including six of the seven herbs containing Aristolochic acid – are used infrequently, for very specific purposes. Xi Xin, the one herb of the seven which contains negligible amounts of the substance, is the only one prescribed more frequently.

Almost all herbal formulae used in TCM comprise mixtures of dried herbs, which are chopped into a fine powder. Either whole or powdered, the herbs are cooked in hot-to-boiling water before they are consumed. TCM practitioners perform this process, called decoction, in order to reduce the potential toxicity of their chemical components. According to Ravid, failure to decoct Chinese herbs might result in unpleasant side effects but is not likely to be lethal.

Xi Xin in Common Use

Ravid uses the herb Xi Xin, which contains negligible amounts of Aristolochic acid, frequently for respiratory and joint problems – always in combination with other herbs. When asked why Xi Xin is still in use, in light of the recent research, Ravid claims that Aristolochic acid is not dangerous in trace amounts (unlike chemical compounds such as ricin, which are toxic in any dose).

When mixed in a medicinal formula with a number of other herbs, he says, the other herbs (and the decoction process) counteract the toxicity, thus making it safe to consume. In addition, he says, short-term use, rather than repeated, chronic, long-term use of a particular medicinal formula limits any damage that might be caused by the accumulation of a particular ingredient in the body.

Supervised Use of TCM Medicinals

Unlike Western medicines, TCM formulae are tailor-made to treat the particular needs of the specific patient, and based on a thorough examination of the patient. Dosages and frequency of consumption are also carefully tailored to meet the patient’s needs. Most formulae are recommended for short-term use, and cannot be refilled without a prescription – which usually depends on re-examination. These standard practices of TCM are part of the basic theory of TCM treatment, which says that the internal workings of the human body are constantly in flux, and that any treatment needs to be based on the current needs of an individual.

Unlike Western medicine, patients with the same or similar symptoms may be treated by entirely different medical formulae in TCM, as the treatment addresses the underlying imbalance, rather than the symptoms of the illness. And, while there are a number of “one-size-fits-all” formulae, most patients are treated individually.

Avoidance of Aristolochic Acid in TCM

TCM practitioners have some 5,000 plant, animal and mineral species from which to choose when designing medical formulae. In addition, substituting one plant species for another is an established practice. Since Aristolochia species are considered interchangeable with a number of commonly used herbal ingredients, it is an easy task for practitioners to totally avoid the use of Aristlochic acid if they wish to do so.

Resources:

Chen, J.K, et all. Aristolochic Acid and Chinese Herbs. (2013). Acupuncture.com. Accessed August 28, 2013.
Chen, J.K. and Chen, T. T. Chinese Medical Herbology and Pharmacology. (2001). Art of Medicine press. Accessed August 28, 2013.
FDA, U.S. Food and Drug Administration. Aristolochic Acid: Safety Alert. (2001). Accessed August 28, 2013.
International Agency for Research on Cancer. A Review of Human Carcinogens, Pharmaceuticals: Volume 100A. (2012). Accessed August 28, 2013.

*Editorial Note* The information in this article is intended for informational purposes only, and does not constitute medical advice. Please see your health care provider with questions about your health or possible treatment options.