Heavy metals in traditional Indian remedies

Abstract

The growing popularity of traditional Indian remedies necessitates a critical evaluation of risks associated with their use. This systematic review aims at summarising all available data relating to the heavy metal content in such remedies. Computerised literature searches were carried out to identify all articles with original data on this subject. Fifteen case reports and six case series were found. Their collective results suggest that heavy metals, particularly lead, have been a regular constituent of traditional Indian remedies. This has repeatedly caused serious harm to patients taking such remedies. The incidence of heavy metal contamination is not known, but one study shows that 64% of samples collected in India contained significant amounts of lead (64% mercury, 41% arsenic and 9% cadmium). These findings should alert us to the possibility of heavy metal content in traditional Indian remedies and motivate us to consider means of protecting consumers from such risks.

Lead (Pb2+) modulation of potassium currents of guinea pig outer hair cells

“…The fact that the effects of Pb 2 + are not completely reversible by washing perhaps is indicative that palliative chelation therapy that prevents or reverses the binding of metallic cations to cellular ligands may not hold excellent promise to prevent or reverse peripheral or central effects of the auditory system due to the effects of Pb 2 + [20]. The association of BLL to a number of neurodevelopmental conditions [12,14,38,46] should not be minimized, however, in spite of the relatively benign effects of Pb 2 + observed in vitro on hair cells in the present investigation, albeit hair cells have an epithelial origin and may therefore react differently than nerve cells. However, based on the present observations, we cannot reconcile differences between acute effects of lead on ion channel function as measured here and potential effects of chronic developmental exposure, which occur in the human population as a cause of hearing loss [5,7,29,31].…”

Single-Center Experience With Drug-Induced Liver Injury From India: Causes, Outcome, Prognosis, and Predictors of Mortality

“…LIVER common constitutional and neurological eff ects may overshadow other systems involvement resulting in fewer patients with hepatitis ( 42,43 ). Alternatively, it is possible that patients who ingest CAM consult institutions that cater to indigenous medicine.…”

The safe usage of herbal medicines: counterindications, cross-reactivity and toxicity

“…15 Furthermore, harvested plant material and/or herbal medicines may become contaminated with heavy metals when stored incorrectly or when treated with chemical preservatives. 16 The levels of heavy metal contaminants is often not measured and reported for herbal medicine preparations.…”

“…18 Mercury compounds are often included in TCM preparations prescribed as tranquilisers and anticonvulsants and for the treatment of ulcers. 16 TCM physicians will also often include lead, cadmium or chromium in herbal medicines for the treatment of heart disease and stroke. 19 A number of studies have sought to estimate the prevalence of heavy metal contamination (whether intentional or unintentional) in traditional herbal medicines.…”

“…For example, one Indian study has reported that 64% of a selection of herbal remedies tested contained lead at potentially toxic concentrations. 16 Furthermore, approximately 95% of Ayuverdic medicines tested were found to contain mercury levels in excess of the legal limit (1 ppm). 20 This same study showed variability of mercury concentrations between similar remedies produced by different manufacturers, also highlighting the need for manufacturing standards.…”