METALS IN MEDICINE AND THE ENVIRONMENT

History and Background

Ayurvedic medicine is a form of traditional Indian medicine and is classified by the National Institutes of Health as a Complementary and Alternative Medicine (CAM).  Its origins can be traced to both the Hindu religion and Persian influences.  The word ayurveda is a Sanskrit word meaning “the science of life.” (1)  Ayurvedic medicine believes that illness is related to an imbalance in the relationship between three forces, called doshas.  These forces are thought to be made up of various elements.  Kapha contains earth and water, Pitta contains fire, and Vata is made up of space and air.  When the three doshas are balanced, a person is healthy; when this is distorted, illness occurs. (2)

Treatment is often through practices such as massage and yoga, but can also include herbal remedies and medicines.  According to the National Center for Complementary and Alternative Medicine (NCCAM), a branch of the National Institutes of Health, two-thirds of India’s rural population uses Ayurvedic medicine to some extent.  In addition, Ayurvedic hospitals and colleges can be found in most urban centers in India and elsewhere in Southern Asia.  NCCAM estimates that in the United States, approximately 751,000 people have tried Ayurvedic medicines and therapies. (1)

Heavy Metal Toxicity in Ayurvedic Medicine

From 1978-2004 there have fifty-eight documented cases of heavy metal toxicity resulting from Ayurvedic medicines in the United States and abroad.  Many of these have involved high levels of lead and have resulted in status epilepticus, fatal infant encephalopathy, congenital paralysis and sensorineural deafness, and developmental delay. (3)  According Roche et al, “The addition of lead is thought to confer fungicidal properties and improve the shelf-life of the products, although Keen et al have written that lead is thought to have aphrodisiac properties to counter autonomic erectile dysfunction in the diabetic male.”(3)  According to Kales et al, “Experts estimate that thirty-five to forty percent of Ayurvedic remedies intentionally contain at least one metal.”(4)  Metals are included in Ayurvedic medicines because they are thought to be active ingredients that restore the harmony of the three doshas.  Ernst notes that, “Ayurvedic textbooks take note of the toxicity of heavy metals and recommend special procedures to ‘detoxify’ them, e.g. heating them until they grow.  Unfortunately, such interventions are not successful in rendering these mixtures non-toxic.”(5)

Current Research

In 2004, researchers at Harvard University’s Oscher Institute published an article in the Journal of the American Medical Association (JAMA) which described their findings of the possibility of heavy metal poisoning from locally purchased ayurvedic medicines.  The researchers purchased medicines from stores throughout the Boston Metropolitan Area; all medicines were manufactured in South Asia (either India or Pakistan).  In total, Ayurvedic remedies came from twenty-seven different manufacturers.  They found that fourteen of the seventy samples (20 percent) contained significant amounts of heavy metals, most notably lead, followed by mercury and arsenic.  Sixty-five percent of the stores visited sold at least one product containing heavy metals.  If the recommended dosage of each of the fourteen medicines were taken, the intake of heavy metals would have been greater than U.S. Pharmacopeia and U.S. Environmental Protection Agency standards.(6)

In a follow-up study conducted by the Cambridge Health Alliance and Harvard Medical School which was published in 2007 in the Medical Science Monitor, researchers described cases of lead poisoning and anemia due to use of ayurvedic medicines.  Forty-seven case studies of adult Ayurvedic lead poisonings were considered; four were cases seen at a clinic associated with the Cambridge Health Alliance and the other forty-three were found by a MEDLINE search of cases from 1966 to November 2005.  Lead poisoning was defined as having a blood level of lead greater than 1.93 μmol/L (40 μd/dl).  A comparison was also done between the levels of lead in these Ayurveda associated cases and those of lead paint removers suffering from lead poisoning.  The researchers found that lead poisoning from Ayurvedic medicine resulted in higher blood lead levels and lower hemoglobin levels.  According to the researchers, “Lead inhibits heme biosynthesis, promotes hemolysis and shortens erythrocyte survival.”  At the same time, twenty-five percent of the Ayurvedic cases of lead poisoning were also know to have been exposed to arsenic.  The researchers also noticed unusual amounts of anemia.  According to Stefanos et al, “Clinically significant anemia in adults is usually uncommon when blood lead is ≤ 3.86 μmol/L (80 μg/dl).  Conversely we found that 75% of Ayurvedic-poisoned patients with blood lead 1.93-3.86 μmol/L had hemoglobin values less than 100 g/L.” (4) In 2004, the Centers for Disease Control published information about twelve cases of lead poisoning due to lead toxicity from Ayurvedic medicine.(7)

Conclusion

The Harvard researchers came to the conclusion that “One of five Ayurvedic HMPs produced in South Asia and available in Boston South Asian grocery stores contains potentially harmful levels of lead, mercury, and/or arsenic. Users of Ayurvedic medicine may be at risk for heavy metal toxicity, and testing of Ayurvedic HMPs [herbal medicine products] for toxic heavy metals should be mandatory.”(6)  Currently, Ayurvedic medicines sold in the United States are classified as dietary supplements, and thus do not fall under the regulation of the Food and Drug Administration.  Instead, any regulation of Ayurvedic remedies would fall under the Dietary Supplement Health and Education Act.  The Cambridge Health Alliance clinical study came to a similar conclusion, stating, “The United States Food and Drug Administration and corresponding agencies in other countries should require heavy metal testing for all imported dietary supplements.”(4)  The study also called for greater awareness among Ayurvedic medicine practitioners about the possibility of heavy metal toxicity.

Resources

National Center for Complementary and Alternative Medicine

Oxford Journal of Evidenced-based Complementary and Alternative Medicine

References

(1) National Center for Complementary and Alternative Medicine.  What is Ayurvedic medicine?  Accessed at: http://nccam.nih.gov/health/ayurveda/, Sept. 23, 2007.

(2) Patwardhan, B., Warude, D., Pushpangadan, P., Bhatt, N.  Ayurveda and traditional Chinese medicine: a comparative overview.  Evid Based Complement Alternat Med.  2, 465-473 (2005).

(3) Roche, A., Florkowski, C., Walmsley, T.  Lead poisoning due to ingestion of Indian Herbal Remedies.  N. Z Med J.  118, U1587 (2005).

(4) Kales, S.N., Christophi, C.A., Saper, R.B.  Hematopoietic toxicity from lead-containing Ayurvedic medications.  Med Sci Monit.  13, CR295-298 (2007).

(5) Ernst, E.  Ayurvedic medicines. Pharmacoepidemiology and Drug Safety.  11, 455-456 (2002).

(6) Saper, R.B. et al.  Heavy metal content of ayurvedic herbal medicine products.  JAMA.  292, 2868-2873 (2004).

(7) Centers for Disease Control and Prevention (CDC).  Lead poisoning associated with ayurvedic medications--five states, 2000-2003.  MMWR Morb. Mortal Wkly Rep. 53, 582-584 (2004).

Author: Sarah Kleinfeld