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Aristolochic acid -- A 'definitely hazardous' herbal compound

By Charles Choi | Staff Writer

May 18, 2004

The product and what it's marketed for: Aristolochic acid is a botanical compound sold to boost weight loss, the immune system and libido, as well as to help against symptoms of depression, menstruation and gastrointestinal problems.

The chemical is found in the Aristolochia family of herbs, which includes birthwort and snakeroot, and in wild ginger, which is often marketed by its scientific name, Asarum canadense.

Aristolochic acid is available on the Internet in products such as Vaxa's PMS-Ease to help diminish pain, cramping and mood swings, and Shanghai Traditional Chinese Herbs' Cardioflex pills to invigorate the blood, stop pain and prevent acute myocardial infarctions. The products note that their statements have not been evaluated by the Food and Drug Administration and that the supplements are not intended to diagnose, treat, cure or prevent any disease.

What's known: Aristolochic acid is a potent human carcinogen. The May issue of Consumer Reports calls it "definitely hazardous," noting that deaths have been reported with the chemical. The FDA warned consumers in 2001 to immediately discontinue use of aristolochic acid due to "potentially serious health risk."

"No one should use aristolochic acid-containing herbs for anything. Aristolochic acid is definitely a bad thing," said Dr. Adriane Fugh-Berman of Georgetown University in Washington, an expert on women's health issues and herbs and dietary supplements.

Aristolochic acid is banned in seven European countries, Egypt, Japan and Venezuela, Consumer Reports notes. The Hong Kong government, starting next month, will prohibit the sale of Chinese herbs and products containing aristolochic acid.

"They should be removed from the shelf," Dr. Ted Kaptchuk of Harvard Medical School, a practitioner of traditional Chinese medicine, said of aristolochic acid products.

In the New England Journal of Medicine in 2000, doctors found that 105 patients given an herbal weight loss product containing aristolochic acid by a Belgian clinic developed kidney damage, with 39 patients requiring kidney removal and 18 found with urinary tract cancer. These patients had used the pills from 1990 to 1992. Kidney failure developed three to 85 months after patients stopped taking the pills.

"It is a scientifically interesting question whether the drugs the people took as part of the slimming regimen amplified adverse effects of aristolochic acid," Fugh-Berman said. "But it's no excuse to use it. We haven't seen a worse adverse effect with an herb. It's a tragedy what happened to these patients, many really quite young."

Aristolochic acid-bearing herbs are used in traditional Chinese medicine, with the root of one species used for hypertension, Fugh-Berman noted. She added the Chinese medicine mu tong is made from several herbs possessing aristolochic acid used as a diuretic, to stimulate heart contractions, and as an antibiotic. An old Chinese text prescribed mu tong for urinary tract and kidney inflammation.

Fugh-Berman favors discontinuing use of this herb as a remedy. "It's good we found this out. Let's ditch it," she said.

"There are dozens of herbs that do what the herbs that aristolochic acid-containing herbs are purported to do that can be substituted. Herbs like Aristolochia shouldn't be used," Kaptchuk said. "People should take Chinese herbs under the guidance of a practitioner with training and a license."

The FDA advises consumers who have taken any supplements containing aristolochic acid to contact their doctor immediately. This includes products listing the words Aristolochia, Bragantia or Asarum. "Even if these products have not been used recently, consumers should still inform their health care provider about which product they took, so that an appropriate evaluation may be conducted," the agency cautions.

Other approaches: Safe herbs with a mild diuretic effect include dandelion and chrysanthemum tea. "For any of the effects you'd want with aristolochic acid, say high blood pressure, you can get with drugs that are much safer," Fugh-Berman said.

Charles Choi is a freelance writer.