Traditional Ayurvedic medicines, which have been used in India for around 2000 years, may contain herbal ingredients that are processed using heavy metals such as mercury, lead and arsenic. While small amounts cause no ill effect and according to the Ayurvedic tradition may possess therapeutic properties, at high levels they can be toxic.
For adults, the US Pharmacopoeia allows a daily maximum of 4.5 micrograms for a daily dose of 1500 mg of calcium carbonate. The US Environmental Protection Agency sets the reference dose for chronic oral intake of mercuric chloride or arsenic for a 70kg adult at 21 micrograms.
AHPA's new trade recommendation, which constitutes a change in the organisation's code of ethics, states: "Whereas traditional Ayurvedic formulas may include ingredients that consist of herbs that are processed with metals; and whereas the presence of several of these metals in herbal dietary supplements sold in the United States may cause such products to be adulterated under the Federal Food, Drug and Cosmetic Act; therefore, AHPA recommends that manufacturers and marketers of herbal products that are based on Ayurvedic traditions refrain from the inclusion in such products of any ingredient that is processed with metals if the resultant presence of heavy metal(s) would cause the product containing the ingredient(s) to be adulterated under labeled or ordinary conditions of use."
Concern over heavy metal products was first raised with the publication of an article in the Journal of the American Medical Association in December 2004, which found that 20 percent of the Ayurvedic herbals analyzed, all of which were on sale in the Boston area, contained lead, arsenic or mercury at levels that would exceed the regulatory standards if taken at the recommended dose.
The researchers said their findings gave good basis for the amendment of DSHEA for mandatory testing of all imported dietary supplements for toxic heavy metals. However AHPA argued that many of the products contained non-herbal ingredients, such as sulfide of mercury, in addition to naturally occurring metals.
These would have contributed to the detection of high heavy metal levels, and would have made them unlawful under DSHEA anyway. AHPA president Michael McGuffin suggested that the problem lies not with DSHEA, but with the importation of the products.
Also at the 15 July meeting the AHPA board amended two of its existing trade recommendations to take into account industry developments.
The first extends the prohibition of labeling products containing goldenseal as being able to mask the results of drug tests to all herbals purported to have that ability.
This move came on the back of a Congressional hearing in May, which discussed products that are marketed with the deliberate intention of masking drug testing, including some that are labeled as dietary supplements.
The second recommendation to be amended involves AHPA's policy on pesticide analysis for ginseng. It identified a specific analytical method, but as the FDA has adopted a different method, it now recommends that processors and manufacturers use "an appropriately validated analytical method at an appropriate and relevant limit of detection".