New Delhi: American doctors have called for mandatory testing of all imported Ayurvedic health products into the United States after discovering potentially toxic amounts of heavy metals in some of them.

They have also advised all Americans who have taken such products "to consult their physicians about heavy metal screening".

The warnings were issued after an analysis of a sample of Ayurvedic Herbal Medicine Products (HMPs) revealed that 20 per cent contained metals such as lead, mercury and arsenic at levels that could be toxic if taken as directed, according to a study in the December 15 issue of the Journal of American Medical Association (JAMA).

Because Ayurvedic HMPs are marketed as dietary supplements in the US, they are regulated under the Dietary Supplement Health and Education Act (DSHEA), which does not require proof of safety or efficacy prior to marketing.

The journal said recent reports of serious lead poisoning associated with taking Ayurvedic HMPs were the impetus for the current study by Robert B Saper and colleagues of the Boston University School of Medicine.

They examined 70 different Ayurvedic HMPs manufactured in South Asia and sold in Boston stores in order to examine their heavy metal content.