MD, PhD, FMedSci, FSB, FRCP, FRCPEd

I don’t suppose that many readers of this blog believe all things natural to be entirely safe, but the general public seems to be hard-wired victims of this myth: Mother Nature is benign, and herbal remedies must be harmless!

There are, of course, several reasons why supposedly “natural” herbal treatments can be unsafe. Plants extracts can be toxic, they might interact with prescribed drugs or they can be contaminated or adulterated.

The latter two terms describe similar but not identical phenomena: contamination means the accidental addition of substances which should not be present in an herbal remedy; and adulteration signifies the deliberate addition of ingredients. If the substances in question are not pharmacologically inert, their presence in herbal remedies can cause adverse effects.

Both contamination and adulteration break laws and regulations; both are therefore illegal. Sadly, this does not mean that such things do not happen.

We have recently published an overview of the existing knowledge in this area. For this purpose, we summarised the evidence from 26 previously published reviews. Our findings were interesting but far from reassuring: the most commonly found contaminants were dust, pollen, insects, rodents, parasites, microbes, fungi, mould, pesticides, and heavy metals. The adulterants invariably were prescription drugs such as steroids, anti-diabetic medications etc.

These substances were implicated in a wide range of serious adverse effects in the unfortunate patients who took the remedies in question: agranulocytosis, meningitis, multi-organ failure, stroke, arsenic poisoning, mercury poisoning, lead poisoning, caner, encephalopathy, hepato-renal syndrome, kidney damage, rhabdomyolosis, metabolic acidosis, renal failure, liver failure, cerebral oedema, coma, and intra-cerebral bleeding. Several patients did not survive.

To avoid such disasters, consumers need to know which types of herbal remedies are most frequently implicated; our review showed that these were foremost Chinese and Indian remedies. While herbal medicines from the US or Europe ought to comply with certain rules and regulations regarding their quality and safety, Chinese and Indian herbal mixtures frequently enter our countries illegally or are bought from dubious sources, for instance, over the Internet. It is this type of herbal remedy that we should be concerned about.

We have to ask whether the risks outweigh the proven benefits of Chinese or Indian herbal mixtures. The short answer to this question is NO. There is very little compelling evidence to suggest that these treatments are efficacious. In the absence of proven benefit, even small or rare risks weigh heavily.

If the risk-benefit profile for any medical intervention fails to be positive, there can only be one reasonable conclusion regarding the use of this therapy – and that is: DON’T DO IT!

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