In a letter in today's issue of The New England Journal of Medicine, Gold, who directs the Carcinogenic Potency Project at UC Berkeley and Lawrence Berkeley National Laboratory, reports that herbal products containing aristolochic acid can be easily purchased through the Internet, despite 105 documented cases of rapid kidney failure due to use in a Belgian clinic in 1993 of a diet supplement containing the herbal extract. Half of the 39 women who had their kidneys removed after taking the supplement were found to have cancer of the urinary tract, the letter notes. Kidney failure associated with aristolochic acid has been seen in eight other countries and urothelial cancer in two other countries, Gold said.

Many names are used for such products, including fang ji (Aristolochia fangchi) and wild ginger (Asarum canadense). The herbal products, which include those marketed as "Cramp Relief," "Cold Away," "Mother Earth's Cough Syrup," "Old Indian Herbal Syrup" and "PMS-Ease," are recommended on the Web for gastrointestinal symptoms, weight loss, cough, immune stimulation and menstrual cramps, among others. A list of products is at http://potency.berkeley.edu.

"Aristolochia and aristolochic acid are known human and rat carcinogens," Gold said in an interview. "What is also disturbing is that the recommended dose for at least one product on the Internet is the same as the dose that gave cancer to rats. These products should not be available."

Gold sent a letter to the FDA in March of this year to alert them to the easy availability of these herbal supplements, after finding on the Web 19 products known to contain aristolochic acid and 95 products suspected to contain the chemical. In Chinese herbal medicine, she said, herbs are often substituted for one another, so purchasers can never be certain what the product contains.

"The availability of aristolochic acid-containing products on the Web two years after an FDA alert was issued reveals a serious flaw in the safety protection afforded the public," she wrote with co-author Thomas H. Slone in the NEJM letter. "The failure to protect the public from the imminent hazard of aristolochic acid indicates that there is an urgent need to remove these products from the Web and to develop a policy that addresses Web sales of hazardous herbal products."

They noted in the letter that "... aristolochic acid is among the most potent two percent of the carcinogens in our Carcinogenic Potency Database." The database, which analyzes long-term cancer studies performed in animals, shows that aristolochic acid causes cancer in rats and mice. Aristolochic acid also damages rabbit kidneys in the same way that aristolochic acid-containing supplements damage human kidneys.

The situation in Belgium resulted from the substitution of Aristolochia for another herb in a diet supplement obtained from China.

"Women in the diet clinic developed kidney damage within a few years, and many of them suffered kidney failure and had transplants," Gold said. "Urothelial carcinoma was found in half the women who had their kidneys removed."

In the March 2, 2003, letter to the FDA, Gold and Slone noted that herbal medications containing Aristolochia species were banned in Germany 20 years ago, and they currently also are banned in Japan, Malaysia, New Zealand and the United Kingdom. In Australia, products known to contain aristolochic acid were canceled, "and all manufacturers are required to ensure that herbs which are likely to be used interchangeably with Aristolochia are free from AA (aristolochic acid)," she wrote.

Thanks to the Dietary Supplement Health Education Act of 1994, Gold said, herbal products do not require FDA approval before marketing, so the safety and efficacy of most are unknown. Another herbal supplement, ephedra, was implicated in the death of baseball pitcher Steve Bechler earlier this year. The death spurred the FDA to consider requiring strong warnings on supplements that contain ephedra, and possible regulation of the supplement.

This week, California became the third state to ban ephedra, prohibiting the sale or distribution of any dietary supplement product containing ephedrine group alkaloids.

"There is a common misconception that natural is good, and that, if it has been part of cultures for many centuries, it must be fine," Gold said. Based on her work with carcinogens, however, she finds that natural chemicals are just as likely to cause cancer as man-made chemicals.

"The fact is, in our database, half the naturally occurring chemicals turn out to be carcinogens just the way half the synthetic chemicals do when they are tested," she said. "Also, many natural agents that have been present throughout vertebrate evolutionary history, such as aflatoxin or the common elements beryllium and arsenic, cause cancer in people."

Note: If no author is given, the source is cited instead.

• Alternative Medicine
• Dietary Supplement
• Kidney Disease

• Food
• Cell Biology
• Soil Types

• Herbalism
• PMS
• Herbal tea
• Detox diet
• Sugar substitute
• Nanomedicine