One Fifth of Ayurvedic Products Contain Heavy Metals

In a welcome study of poorly regulated dietary supplements, investigators in Boston report the presence of toxic heavy metals—namely lead, mercury, or arsenic—in one fifth of US- or Indian-made Ayurvedic products. Results of a metal survey of these Internet-sold drugs were published in the latest issue of JAMA.

Among 199 of 230 randomly selected Ayurvedic medicines available for web-based purchase,* nearly 21% contained metals per x-ray fluorescence spectroscopy, wrote the authors, with no appreciable difference between US- and Indian-made products. Rasa shastra drugs—which combine herbs with metals, minerals, and gems—were significantly more likely to contain metals than non-rasa shastra products (41% vs 17%) and contained significantly higher median concentrations of lead (11.5 vs 7.9 µg/g) or mercury (20,800 vs 34.5 µg/g).

The amount of metals detected in metal-containing products consistently exceeded one or more standards for acceptable daily intake. These drugs were much more likely to be sold at US web sites (Table), and 75% claimed Good Manufacturing Practices, wrote the authors. In some cases, products were specifically recommended for pediatric use.

These findings are consistent with those of a previous report, in which 20% of 70 Ayurvedic products made in South Asia and sold in Boston contained higher-than-regulatory amounts of lead, mercury, or arsenic. Scores of clinically symptomatic cases of heavy-metal intoxication due to the ingestion of Ayurvedic drugs have been reported since 1978.

* One web-based supplier of Ayurvedic products refused to fill an order for 14 products after recognizing that the purchasers were authors of a previous study.