Researchers Find High Levels Of Potentially Toxic Heavy Metals In Herbal Medicine Products

"We tested Ayurvedic HMPs sold in Boston areas stores and found they had unacceptably high heavy metal content," said Robert Saper, MD, MPH, currently with the Boston University School of Medicine (BUSM) Department of Family Medicine and a former research fellow at the Harvard Medical School (HMS) Osher Institute and Beth Israel Deaconess Medical Center.

"This study, yet again, highlights the need for Congress to revisit the way dietary supplements are regulated in the U.S.," said co-author David Eisenberg, MD, the Bernard Osher Associate Professor of Medicine and Director of the HMS Division of Research and Education in Complementary and Integrative Medical Therapies. "Our first priority must be the safety of the public. Over-the-counter herbs and supplements with high levels of heavy metals are simply dangerous," he said.

Ayurvedic medicine originated in India more than 2,000 years ago and relies heavily on herbal medicine products. In India, an estimated 80% of the population uses Ayurveda. In the United States, Ayurvedic remedies have increased in popularity and are available from South Asian markets, Ayurvedic practitioners, health food stores, and on the Internet. Several recent reports of Ayurvedic medicine users developing life-threatening lead toxicity prompted the current study.

The researchers tested 70 HMPs at the New England Regional Environmental Protection Agency Laboratory and found 14 (20 percent) contained lead, mercury, and/or arsenic. Each of the 14, if taken as recommended by the manufacturers, could result in heavy metal intakes above regulatory standards. Several of the HMPs, such as Mahayograj Guggulu and Navratna Rasa, could result in lead and arsenic intakes of 1,000 - 10,000 times greater than the regulatory standards. Half of the HMPs containing potentially toxic heavy metals were recommended by the manufacturers for use in infants and children. Eleven different manufacturers produced one or more HMPs containing heavy metals. Eighty percent of the 30 stores sold at least one HMP which contained significant amounts of heavy metals.

"Users of Ayurvedic medicines manufactured in South Asia may be at risk for heavy metal toxicity," said Saper, the lead author of the study and Director of Integrative Medicine in the Family Medicine Department at BUSM. "While the exact extent of Ayurvedic HMP use in the U.S. and abroad is unknown, the numbers of individuals at potential risk are substantial. Domestic and international public health and community organizations should issue advisories to current or previous users of Ayurvedic HMPs manufactured in South Asia to consult their physicians about screening for heavy metal toxicity."

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. The researchers believe that testing Ayurvedic HMPs should not only be mandatory, but call for reform that would require mandatory testing of all imported dietary supplements for toxic heavy metals.

"In order to investigate the efficacy of commonly used dietary supplements ­ including Ayurvedic remedies ­ we need to test high-quality standardized products free of contaminants and dangerous toxins," said Eisenberg. "This study reminds us of the need for regulatory reform involving dietary supplements used by the American public."