In a finding that will have serious adverse impact on ayurveda industry in the country, the Journal of American Medical Association (JAMA) has found that close to 21 per cent of ayurvedic medicines manufactured and distributed by US and Indian companies through internet contain heavy metal contamination such as lead, mercury or arsenic beyond the permissible limit. The study was published on August 27, 2008.

The study said that lead, mercury and arsenic have been detected in a substantial proportion of Indian-manufactured traditional ayurvedic medicines. Metals may be present due to the practice of rasa shastra (combining herbs with metals, minerals and gems). Whether toxic metals are present in both US- and Indian-manufactured ayurvedic medicines is unknown.

The findings of the study will have its adverse impact on the Indian ayurvedic industry as it comes at a time when the industry and the authorities are taking umpteen measures to improve the quality of the medicines. The study calls for regulation of dietary supplement products which are marketed through Internet and introduction of heavy metal testing for dietary supplements (marketed in the USA). The study was authored by well known medical experts in the US such as Robert B Saper, Russell S Phillips, Anusha Sehgal (Ayurveda), Nadia Khouri, Roger B Davis, Janet Paquin, Venkatesh Thuppil, and Stefanos N Kales.

For the study, the experts had identified 673 products which the JAMA had procured through 25 web sites offering traditional ayurvedic herbs, formulas or ingredients commonly used in ayurveda, indicated for oral use and available for sale. From this list, 230 ayurvedic medicines were randomly selected by JAMA for purchase in August-October 2005. Country of manufacturer/web site supplier, rasa shastra status, and claims of Good Manufacturing Practices were recorded. Metal concentrations were measured using x-ray fluorescence spectroscopy.

The results showed that 193 of the 230 requested medicines were received and analyzed. The prevalence of metal-containing products was 20.7 per cent (95 per cent confidence interval [CI], 15.2 per cent-27.1 per cent). The prevalence of metals in US-manufactured products was 21.7 per cent (95 per cent CI, 14.6 per cent-30.4 per cent) compared with 19.5 per cent (95 per cent CI, 11.3 per cent-30.1 per cent) in Indian products (P = .86). Rasa shastra compared with non-rasa shastra medicines had a greater prevalence of metals (40.6 per cent vs 17.1 per cent; P = .007) and higher median concentrations of lead (11.5 µg/g vs 7.0 µg/g; P = .03) and mercury (20 800 µg/g vs 34.5 µg/g; P = .04). Among the metal-containing products, 95 per cent were sold by US Web sites and 75 per cent claimed Good Manufacturing Practices. All metal-containing products exceeded 1 or more standards for acceptable daily intake of toxic metals.