Ayurvedic medicines -- herbal mixtures dating back thousands of years in India and increasingly popular in the West -- are frequently contaminated with lead, mercury or arsenic, according to a study published today.
A fifth of the nearly 200 concoctions tested contained levels of the toxic metals that, if taken at the maximum recommended doses, would surpass California's safety guidelines.
Dr. Robert Saper, a Boston University professor of family medicine who led the study, said the findings should spur the Food and Drug Administration to start clamping down on the largely unregulated world of pills, herbs and powders classified as dietary supplements.
"It shouldn't be me trying to figure this out," Saper said.
Ayurveda is a traditional Indian practice that takes a holistic approach to wellness, employing herbal medicine, meditation and exercise to promote good health. It exists alongside modern medicine in India, with its own network of clinics, hospitals and colleges serving hundreds of millions of patients.
It has spread to the U.S. and Europe with the migration of South Asians around the world and been popularized by figures such as bestselling author Deepak Chopra.
There are about two dozen ayurvedic training programs in the United States. A 2002 survey estimated that 750,000 U.S. residents have used the herbal preparations, sold under both traditional Indian names and more marketable labels such as GlucoRite and Ezi Slim.
Saper got interested in the supplements in 2003 after a man of Indian origin showed up at a Boston-area emergency room with seizures. The culprit turned out to be lead in the man's ayurvedic medicines. In an initial study published in 2004, Saper bought 70 ayurvedic products imported from India and found that toxic metals were common components.
It was an unsettling finding, because most of the preparations are intended to be taken as part of a daily regimen to improve health.
"Many, many studies are showing that even small levels of lead in the blood can increase the risk of high blood pressure, kidney dysfunction and decreased IQ," Saper said.
Ayurvedic practitioners lashed out at the research as alarmist, saying that it only showed there were problems with mixtures from India, not with U.S.-made products.
They pointed out that in India, many of these metals are purposely blended with herbs as part of the medicinal recipe. Those metallic mixtures are rarely used in the United States, they said.
In the new study, published in the Journal of the American Medical Assn., Saper and his team analyzed 193 products purchased from 25 websites for Indian and U.S. manufacturers. The vast majority supposedly contained only herbs and no metals.
About 80% of the samples showed no detectable metal content. But among the remaining samples, the toxic metals showed up at similar rates in both U.S. and Indian-made products. Of the U.S. products, 21% contained lead, 3% contained mercury and 3% had arsenic. Among the Indian-made medicines, 17% had lead, 7% had mercury and none contained arsenic.
The researchers and other experts surmised that the contamination had less to do with the manufacturing process than with the soils in which the herbs were grown.
"The raw material is all coming from India," said Kush Khanna, who runs Bazaar of India in Berkeley, a manufacturer of ayurvedic medicines started by his father in 1971.
Heavy metals showed up in 17 of the products the researchers ordered from his company.
Khanna said two labs in India routinely tested the 80 or so ingredients he imported.
The problem is that there are no unified standards for what is considered safe.
Lead levels allowed by the World Health Organization are 500 times the California limits.
"Based on WHO standards, our products are perfect," Khanna said. "They have not exceeded any limits."
The researchers found only two products that exceeded the WHO standards for lead content. Both mixtures were from India and purposely prepared with metals as ingredients.
In California, the Safe Drinking Water and Toxic Enforcement Act of 1986 requires that products containing certain levels of toxic metals carry warning labels. But the act has no power to ban products, and companies with fewer than 10 employees, such as Khanna's, are exempt from the labeling requirements.
The FDA does not specify any limits for metal content in dietary supplements, leaving it to the manufacturers to ensure that their products are safe.
Jennifer Rioux, a medical anthropologist who runs the Integral Ayurveda clinic in Chapel Hill, N.C., said the research underscored the need for consumers to consult with ayurvedic experts instead of buying and taking products on their own.
She noted that the study showed many medicines to be perfectly safe, but she worried that its conclusions would tar her profession.
"All people need is one study to provoke fear about an entire system of medicine," she said.