By Dr CM Pradyumna

An Ayurvedic approach to the issue.

The recent publication of “Heavy Metal contents of Ayurvedic herbal medicine products” based on research findings by the American Medical Association Journal has made news in the media and on the internet asking people to exercise caution over the use of herbal medicines. The Telegraph published an article under the title “Slur on Herbal dirty dozen” on 16th Dec 2004pg:5 col 1.

The study seems to be unbiased and they have accepted very clearly that their study has limitations and so cannot be generalized because of the following observations -

  • Statistical data about the number of people on Ayurvedic medicines0.8 billion in India and 7,50,000 in the U.S.A
  • Number of cases of herbal medicine related heavy metal toxicity. 55 cases in 24 years
  • Whether these patients have taken medicines by prescription from a qualified Ayurveda practitioner or were they on a strict dietetic regimen - Not known
  • Number of individual Ayurveda medicines 6000 approximately
  • Percentage of medicines actually containing metals and minerals in processed form. 20 % approximately
  • Can just the presence of heavy metal mean that it can create toxicity? - Uncertain
  • Do these compounds really get absorbed into the blood stream? Unknown
  • Do plants have heavy metals in them by nature? - Uncertain

Further the ambiguity is deepened by these facts
  • Uncertainty over source of heavy metals in the samples whether they are added intentionally, incidentally or whether they are already present in the raw herbs naturally.
  • They are not very clear about which of those medicines are likely to produce toxicity clinically and when taken for how long and at what dosage, whether or not supported by strict dietetics.
  • Inability to ascertain the metals’ chemical forms, which can impact bio-availability and toxicity.
The pharmacological section of Ayurvedic system of medicine recognizes 3 major sources of medicine, those of herbal origin (ex: herbs), mineral origin (ex: salt, metals like gold, silver, iron etc) and animal origin (ex milk, honey etc). Kashtaushadha (purely herbal) and Rasaushadha (herbo-mineral/metallic) are the 2 main groups of medicines. The former is devoid of any metals or minerals and is purely a herbal product and can be considered as the safest of medicines and this class of medicines are used more frequently and up to 80% of prescription medicines consist of Kashtaushadhas, and the latter (rasaushadha) contains metals and minerals in the form of Bhasmas or compounds which are considered as potent medicines in Ayurvedic pharmacology that have to be used with utmost caution.

Bhasmas are that form of metals which have undergone stringent processing and incineration and reduced to finest ash (Bhasma). Studies have revealed that these metals lose their chemical identity after they are made into the Bhasmas, and this quality control measure in Ayurveda is technically termed as Apanurbhava, meaning the metal or mineral has undergone a permanent and irreversible change both physically and chemically. For example loha bhasma (iron ash) prepared as per prescribed procedures is chemically not identical with iron (ferrous / ferric compounds) the same holds good for other metals and minerals. One more fact is that people who are known allergic to these metals / minerals have no symptoms of allergy whatsoever to Ayurvedic medicines containing them in a processed form.

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