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 Shasta, combining herbs with metals, minerals, and gems.
|The prevalence of metal-containing products was 21%|
|Journal of the American Medical Association|
Whether toxic metals are present in both USA- and Indian-manufactured Ayurvedic medicines is unknown.
Dr Robert Saper and colleagues from Massachusetts, USA determined the prevalence of Ayurvedic medicines available via the Internet containing detectable lead, mercury, or arsenic.
The research team compared the prevalence of toxic metals in USA- vs Indian-manufactured medicines and between rasa shastra and non-rasa shastra medicines.
The team search used 5 Internet search engines.
The search terms Ayurveda and Ayurvedic medicine.
The team identified 25 Web sites offering traditional Ayurvedic herbs, formulas, or ingredients commonly used in Ayurveda, indicated for oral use, and available for sale.
From 673 identified products, the research team selected 230 Ayurvedic medicines in 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 team used prevalence of medicines with detectable toxic metals in the entire sample, and stratified by country of manufacture and rasa shastra status.
The researchers received and analyzed 193 of the 230 requested medicines.
The prevalence of metal-containing products was 21%.
The team found the prevalence of metals in USA-manufactured products was 22% compared with 20% in Indian products.
Rasa shastra compared with non-rasa shastra medicines had a greater prevalence of metals, occurring in 41% vs 17%, and higher median concentrations of lead, and mercury.
Among the metal-containing products, 95% were sold by USA Web sites, and 75% claimed Good Manufacturing Practices.
All metal-containing products exceeded 1 or more standards for acceptable daily intake of toxic metals.
Dr Saper's team concluded, "One-fifth of both USA-manufactured and Indian-manufactured Ayurvedic medicines purchased via the Internet contain detectable lead, mercury, or arsenic."