|Herb in weight-loss pill
causes cancer, damages kidneys, researchers report
June 8, 2000
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
"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.
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
Severe side effects
In animal studies, Aristolochia fangchi has caused kidney damage and cancer, the study
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
"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
"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
Cordaro's group urges consumers to read the labels of all dietary supplements completely
before using the product.