Herb in weight-loss pill causes cancer, damages kidneys, researchers report

June 8, 2000
Web posted at: 3:33 p.m. EDT (1933 GMT)

From staff and wire reports

ATLANTA (CNN) - Eighteen people taking weight-loss pills containing a Chinese herb have developed cancer, and scores more people suffered severe kidney damage, according to a study published in this week's New England Journal of Medicine.

"Our findings reinforce the idea that the use of natural herbal medicine may not be without risk," wrote Dr. Joelle L. Nortier, a kidney specialist at the Free University of Brussels, Belgium.

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The pills were prescribed to patients in Belgium between 1990 and 1992; they were not available over the counter.

Nortier's study found that in a manufacturing error of the weight-reducing pills, one of the herbs -- Stephania tetrandra -- was replaced by Aristolochia fangchi, an herb related to herbs variously called birthwort, snakeroot, dutchman's pipe, pipe vine and calico flower.

Severe side effects

In animal studies, Aristolochia fangchi has caused kidney damage and cancer, the study said.

In Belgium, the herb damaged the kidneys of 105 patients and caused 18 cases of cancer among them, the researchers reported. And they said there is a positive correlation between the cumulative use of the herb and kidney diseases.

"Our evidence indicates that the regular intake of powdered Chinese herbs of the Aristolochia species dramatically increases the risk of urothelial carcinoma (cancer of the linings of kidneys, bladders and related tubes)," the study said.

Nortier said other cases of kidney damage from Chinese herbs have been reported in France, Spain, Japan, Britain and Taiwan. The researchers recommended that doctors ask patients with unexplained kidney disease or tumors about possible herbal use.

The U.S. Food and Drug Administration announced Friday it is stopping imports of herbs in the Aristolochia family because they had caused kidney failure in Belgium and in Britain, where they were being used to treat a skin condition.

Calls for more regulation in the U.S.

Dr. David Kessler, former FDA head and now dean of Yale's medical school, called Nortier's findings "striking" and "worrisome" in an editorial accompanying the study. He said the results "should persuade Congress to change the law" to tighten the FDA's control over these types of supplements.

Aristolochia fangchi's name in Chinese is similar to that of Stephania tetrandra, and it often is substituted for the Stephania, according to Kessler.

"Since there is virtually no control over the quality of these products, it is not unusual not to know what is actually in herbal preparations and dietary supplements," he said.

Sales of dietary supplements bring in $15 billion a year in the United States. Kessler said the government needs to do more to control such products.

"Congress has tied the agency's hands in regulating dietary supplements, both in regard to safety and to efficacy. Unfortunately, harm has to occur before FDA can regulate a dietary supplement," he said.

But industry representatives say safety is their primary concern.

"The dietary industry needs a U.S. Food and Drug Administration that is effectively and efficiently and immediately enforcing the laws that now exist," said John Cordaro of the Council for Responsible Nutrition. "It's been the responsibility of the dietary supplement industry to take a lot of self-regulatory action."

Cordaro's group urges consumers to read the labels of all dietary supplements completely before using the product.

CNN Medical Correspondent Dr. Steve Salvatore and The Associated Press contributed to this report.

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Council for Responsible Nutrition
Welcome to the American Herbal Products Association (AHPA)
NIH Office of Dietary Supplements
FDA/CFSAN Office of Special Nutritionals: Information about Dietary Supplements

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