Some herbal medicine products contain potentially toxic amounts of heavy metals

An analysis of a sample of Ayurvedic herbal medicine products found that 20 percent contained metals such as lead, mercury and arsenic at levels that could be toxic if taken as directed, according to a study in the December 15 issue of JAMA.

According to background information in the article, approximately 80 percent of India’s one billion population uses Ayurveda, a medical system that originated in India more than 2000 years ago and greatly relies on herbal medicine products (HMPs). Ayurveda’s popularity in Western countries has increased. Because Ayurvedic HMPs are marketed as dietary supplements, they are regulated under the Dietary Supplement Health and Education Act (DSHEA), which does not require proof of safety or efficacy prior to marketing. Herbs, minerals and metals are used in Ayurvedic HMPs. Recent reports of serious lead poisoning associated with taking Ayurvedic HMPs were the impetus for the current study.

Robert B. Saper, M.D., M.P.H., formerly of Harvard Medical School, Boston, (currently with the Boston University School of Medicine) and colleagues examined Ayurvedic HMPs manufactured in South Asia and sold in Boston-area stores in order to examine their heavy metal content. From April to October 2003, the researchers purchased 70 different Ayurvedic HMPs at stores within 20 miles of Boston City Hall. Concentrations of lead, mercury and arsenic were measured in the samples. The potential amount of daily metal ingestion, estimated by using manufacturers’ dosage recommendations, was compared to U.S. Pharmacopeia and U.S. Environmental Protection Agency regulatory standards.

The researchers found that 14 (20 percent) of the 70 HMPs contained lead, mercury and/or arsenic, and that if taken as recommended by the manufacturer, each of these could result in heavy metal intake above the published regulatory standards. Lead was found in 13 HMPs; mercury in six HMPs; and arsenic in six HMPs. Half of the HMPs containing potentially toxic heavy metals were recommended for children. The 14 HMPs containing heavy metals were manufactured by 11 different companies. Of the 30 stores visited, 24 sold at least one heavy metal-containing HMP.

“… the presence of heavy metals in Ayurvedic HMPs and the numerous reports of associated toxicity may have important public health, clinical, and policy implications in the United States and abroad. Although the prevalence of heavy metal–containing Ayurvedic HMP use is unknown, the number of individuals at potential risk is substantial,” the authors write. “Public health and community organizations should consider issuing advisories to current or previous Ayurvedic HMP users, encouraging them to consult their physicians about heavy metal screening.”

“Our findings support calls for reform of DSHEA that would require mandatory testing of all imported dietary supplements for toxic heavy metals,” they conclude.