BOSTON – There’s some disturbing news for those who use ayurvedic medicine: Many of the herbal products sold on the Internet for ayurveda contain dangerous leavels of lead, mercury and arsenic, according to a new study.

Ayurveda is an ancient form of medicine that orginated in India and uses herbal products, including some known as Rasa shasta that deliberately mix herbs with metals, minerals and gems. Ayurvedic experts believe that if such products are prepared and administered properly they are safe and effective.

But several studies have indicated that the levels of toxic metals found in these products may be unsafe. To try to get a sense of the safety of the products sold over the Internet, Robert Saper at the Boston University School of Medicine and his colleagues identified 25 websites featuring 673 ayurvedic medicines. They randomly selected, purchased and tested 193 products made by 37 manufacturers.

More than 20 percent of the products contained detectable lead, mercury and/or arsenic, the researchers reported in this week’s issue of the Journal of the American Medical Association. Products made in the United States were no less likely to contain the toxins than those produced in India, the researchers found. Rasa shasta products were more than twice as likely to contain metals and had high concentrations of lead and mercury.

All the products containing metal exceeded at least one standard for acceptable metal intake and several of the products made in India could result in lead and/or mercury ingestions 100 to 1,000 times greater than acceptable limits, the researchers reported. Among the products containing metal, 95 percent were sold by U.S. websites and 75 percent claimed to follow “Good Manufacturing Practices.”

The researchers said the findings underscore the recommendations of a 2005 National Academy of Sciences report that Congress give the Food and Drug Administration greater authority to regulate herbal remedies.

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