Lead, mercury, and arsenic in US- and Indian-manufactured Ayurvedic medicines sold via the Internet

Abstract

Context: 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.

Objectives: To determine the prevalence of Ayurvedic medicines available via the Internet containing detectable lead, mercury, or arsenic and to compare the prevalence of toxic metals in US- vs Indian-manufactured medicines and between rasa shastra and non-rasa shastra medicines.

Design: A search using 5 Internet search engines and the search terms Ayurveda and Ayurvedic medicine 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, 230 Ayurvedic medicines were randomly selected 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.

Main outcome measures: Prevalence of medicines with detectable toxic metals in the entire sample and stratified by country of manufacture and rasa shastra status.

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

Conclusion: One-fifth of both US-manufactured and Indian-manufactured Ayurvedic medicines purchased via the Internet contain detectable lead, mercury, or arsenic.

Figure

Estimated Daily Ingestion Amounts of Lead, Mercury, and Arsenic for Metal-Containing Ayurvedic Medicines Estimated daily ingestion levels for the respective metal-containing Ayurvedic medicines were calculated using the mean metal concentration in the product, unit dose weight, and recommended dosage(s) stated on the label. If the manufacturer recommended a range of dosages, a range of potential daily ingestion amounts is shown. India- and US-made products are shown in red and black, respectively. ^aCalifornia Proposition 65 has established a maximum allowable dose level for lead of 0.5 μg/d. ^bAmerican National Standards Institute/National Sanitation Foundation International Dietary Supplement Standard 173 (ANSI 173) states that dietary supplements should not contain undeclared metals that would cause intakes greater than 20 μg/d of lead, 20 μg/d of mercury, and 10 μg/d of arsenic. ^cFood and Agricultural Organization/World Health Organization Joint Expert Committee on Food Additives (FAO/WHO JECFA) provisional tolerable weekly intakes correspond to acceptable intakes of 250 μg/d of lead, 50 μg/d of mercury, and 150 μg/d of arsenic for a 70-kg person. ^dRasa shastra medicine.^e United States Environmental Protection Agency reference doses (EPARfDs) for chronic oral intake of mercuric chloride and arsenic are both 0.3 μg/kg/d, corresponding to 21 μg/d for a 70-kg adult.