I saw this in today's Guardian. A team led by Robert Saper of the Boston Medical Centre ordered 230 different ayurvedic medicines from websites, and analysed the 193 they actually received for metal content [interesting that they never received 37 of them...]. For those interested, the paper is in JAMA 300 (8): 915-923, but it's behind a paywall...
What is Ayurvedic medicine? It's not something I know a lot about, but it's a traditional form of Indian medicine. Medicines are made up of herbs or mixtures of herbs, which can be combined with metals, minerals or animal products. The medicines that include metals, minerals or gems are known as rasa shastra medicines. As is typical for any form of alternative medicine, Ayurveda is described as being safe and natural by the various people who sell it: try a simple Google search to see what I mean. But how safe are they really?
Well, according to Saper and colleagues, a good proportion of them are stuffed full of heavy metals. Of the 193 medicines they analysed, 20.7% contained detectable levels of lead, mercury or arsenic. Unsurprisingly, metals were more prevalent in the rasa shastra medicines, of which 40.6% had detectable levels of nasty metals. The authors then took the recommended doses for each of the metal-containing medicines, and calculated what the daily intake of heavy metals would be for someone taking the medicine according to the stated dose. They found that for ALL of the medicines that contained detectable metal levels, a person taking the recommended dose would exceed standards for the ingestion of heavy metals. For some of the medicines manufactured in India, ingestion of heavy metals exceeded the limits by up to 10,000 times.
Pretty scary, eh? There are some caveats here. Firstly, these medicines were bought online: the authors concede that the results may not be similar for medicines given in consultation with an Ayurveda practitioner, or over the counter in western pharmacies. Even so, a previous study of medicines sold in Boston by Saper and colleagues showed that 20% contained lead, mercury or arsenic. So be careful: it is clear that while Ayurveda may be a 'natural' alternative to conventional medicine, it is not necessarily 'safe', as these case reports also testify. This is why conventional medicines are tested for safety before they can be sold. While there is no doubt that the evidence-based process of efficacy and safety testing can sometimes go wrong, it should be supported; the alternative is taking medicine of no proven benefit and with no understanding of the risks. This is too often what happens with inadequately regulated alternative treatments.