Heavy Metal Contamination of Ayurvedic Herbal Medicine Products

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  • Ayurveda
  • Heavy Metal Contamination
  • Herbal Medicine Products
  • Date: January 31, 2005 HC# 010155-273

    Re: Heavy Metal Contamination of Ayurvedic Herbal Medicine Products

    Saper R, Kales S, Paquin J, et al. Heavy metal content of Ayurvedic herbal medicine products. JAMA. 2004 December 15;292(23):2868-2873.

    According to authors, at least 55 cases of heavy metal toxicity associated with the use of Ayurvedic herbal medicine products (HMPs) have been reported since 1978. For example, lead toxicity associated with Ayurvedic HMP use has resulted in fatal infant encephalopathy (disease of the brain; especially, in regards to brain structure), congenital paralysis, deafness, and developmental delays. In recent years, the popularity of Ayurvedic HMPs has increased in the United States, where HMPs are available for purchase from South Asian markets, Ayurvedic practitioners, health food stores, and the Internet. Because HMPs are usually considered dietary supplements, they are regulated under the Dietary Supplement Health and Education Act of 1994 (DSHEA), which, unlike conventional drugs, does not require manufacturers to provide proof of safety and efficacy before marketing. Furthermore, no known studies have specifically measured the heavy metal content of Ayurvedic HMPs. The objective of this study was to determine the prevalence and concentration of heavy metals in a sample of Ayurvedic HMPs purchased in the Boston area of Massachusetts. According to a recent article in HealthDayNews,1 the impetus for this study was the recent admittance of a man experiencing intractable seizures to a Boston area hospital. An interview with the patient's family revealed that the patient had been taking Guggulu (part of which contains the traditional Ayurvedic gum resin Commiphora mukul with other herbs), an Ayurvedic treatment for arthritis, for the past 6 years. An analysis of this particular product showed high levels of lead, mercury, and arsenic.

    The authors identified all ethnic Indian stores selling Ayurvedic HMPs within a 20-mile radius of Boston City Hall and then purchased, from each of these stores, those products that were manufactured in South Asia and that were intended for oral use. The following information was recorded for each of the 70 unique HMPs purchased: name, manufacturer's name and location, lot number, formulation, indications, recommended dosages, and cost per package. The concentrations of lead, mercury, and arsenic in each of the HMP samples were measured by X-ray fluorescence spectroscopy at the New England Regional Laboratory of the Environmental Protection Agency (North Chelmsford, MA). Estimates of the daily ingestion of these heavy metals were compared with reference doses established by the Environmental Protection Agency and the US Pharmacopoeia.

    A total of 14 (20%) of the 70 HMPs tested contained lead, mercury, and/or arsenic; 7 of these products were recommended for use in children. A tabular listing of these 14 HMPs and their manufacturers, formulations, and concentrations of lead, mercury, and arsenic is provided in the article. The median concentrations of lead, mercury, and arsenic were 40, 20,225, and 430 mcg/g, respectively. All 14 HMPs, if taken according to the manufacturer's recommended dosage, could result in heavy metal intakes that are higher than published regulatory reference doses—2–3 times the reference dose in some cases. Split-sample retesting was repeated for all 14 HMPs found to contain heavy metals and for 14 randomly selected HMPs that were negative for heavy metals. Ten of the HMPs were able to be repurchased for retesting; for the 4 remaining HMPs, testing was conducted on portions of the original samples. The 10 repurchased samples had lead, mercury, and arsenic concentrations similar to those of the original samples (112%, 118%, and 112% of the original concentrations, respectively). The 14 negative HMPs did not contain heavy metals on retesting.

    The findings of this study are consistent with those from studies of Ayurvedic HMPs sold outside the United States. In England, 30% of the HMPs tested contained heavy metals.2 In India, 64% of 22 samples contained lead and mercury, and 41% contained arsenic.3 HMPs from Japan, India, China, Malaysia, Mexico, Africa, and the Middle East have also been found to be contaminated with heavy metals. The samples tested in the current study had an "unacceptably high heavy metal content" because the amounts measured have been shown to be associated with both toxic blood concentrations and symptomatic poisoning and because epidemiologic evidence indicates that "even HMPs with relatively lower levels of lead (<100 mcg/g) may be deleterious."

    It should be noted that this study had several limitations, one of which was the author's failure to determine the chemical forms of the heavy metals found, which can affect bioavailability and toxicity. Another limitation was that the HMPs tested were purchased from a relatively small geographical area; thus, it is unclear whether the findings can be generalized to HMPs sold elsewhere in the United States. Since all of the products tested were purchased from ethnic Indian grocery stores and were imported directly from India and south Asia, it could be argued that they do not generally reflect the type of Ayurvedic products sold in health food stores or in other parts of the herbal industry. In fact, in another recently published analysis of herbal dietary supplements made in the United States, "Results indicated that the botanical supplements analyzed did not contain unacceptable concentrations of these metals."5 The analysis tested eight different types of herbal supplements (echinacea, garlic, ginkgo, 'ginseng', grape seed extract, kava, saw palmetto, and St. John's wort manufactured by at least seven different companies.

    Furthermore, the American Herbal Products Association4 stated in a recent release that the authors of this study failed "to clarify…that many of these products intentionally contain non-herbal ingredients, such as sulfide of mercury, which no doubt accounts for the high levels of heavy metals detected in these imported products." This is consistent with the traditional use of process, heated heavy metals in Ayurveda. Despite these limitations, the authors state that "the presence of heavy metals in Ayurvedic HMPs and the numerous reports of associated toxicity may have important public health, clinical, and policy implications in the United States and abroad." They further state that their findings "support calls for reform of DSHEA that would require mandatory testing of all imported dietary supplements for toxic heavy metals." Presumably, when the Food and Drug Administration publishes its final rules for good manufacturing practices (GMPs) for dietary supplements, testing for heavy metal contamination in dietary ingredients and imported botanical preparations will become commonplace.

    —Brenda Milot, ELS

    1Gardner A. Heavy metals found in Indian herbs. HealthDayNews. 2004;Dec. 14.

    2Aslam M Davis SS, Healy MA. Heavy metals in some Asian medicines and cosmetics. Public Health. 1979;93:274-284.

    3McElvaine MD, Harder EM, Johnson L, Baer RD, Satzger RD. Lead poisoning from the use of Indian folk medicines. JAMA. 190;264:2212-2213.

    4JAMA article finds heavy metals in Ayurvedic products. AHPA Update. 2004;Dec. 14.

    5Raman P, Patino L, Nair M. Evaluation of metal and microbial contamination in botanical supplements. J Agric Food Chem. 2004;52:7822-7827.

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