Ayurvedic medicines (based on a traditional medical system commonly used in India) are divided into two major types: herbal-only and rasa shastra, which is an ancient practice of deliberately combining herbs with metals (for example mercury, lead, iron, zinc), minerals (as mica) and gems (as pearl).
The researchers conducted a study to determine the prevalence of Ayurvedic medicines available via the Internet containing detectable lead, mercury, or arsenic and compared the prevalence of toxic metals between U.S.- and Indian-manufactured products, and in rasa shastra versus non-rasa shastra medicines.
The scientists conducted an Internet search using the search terms Ayurveda and Ayurvedic medicine and identified 673 products, of which 230 Ayurvedic medicines were randomly selected for purchase in August to October 2005. Country of manufacturer and web site supplier, rasa shastra status, and claims of Good Manufacturing Practices were recorded. Metal concentrations were measured using x-ray fluorescence spectroscopy. One hundred ninety-three of the 230 requested medicines were received and analysed.
The researchers found that the prevalence of metal-containing products was 20.7 percent and that the prevalence of metals in U.S.-manufactured products was 21.7 percent, compared with 19.5 percent in Indian products. Rasa shastra medicines were more than twice as likely as non-rasa shastra products to contain detectable metals and had higher median (midpoint) concentrations of lead and mercury.
Among the metal-containing products, 95 percent were sold by U.S. web sites and 75 percent claimed Good Manufacturing Practices. All metal-containing products exceeded one or more standards for acceptable daily metal intake. “Several Indian-manufactured rasa shastra medicines could result in lead and/or mercury ingestions 100 to 10,000 times greater than acceptable limits”, the authors write.
MEDICA.de; Source: American Medical Association (AMA)