Herbal ‘Medicines’ Skimping on the Herbs?

A misconception is to conflate natural with healthy and synthetic with unhealthy. This misconception is easily cleared up by pointing out that botulinum toxin is 100% natural, but also the most toxic substance known to man. However illogical, this perception is boosting the herbal ‘medicine’ industry and if recent evidence is an indication, for some companies, demand is outstripping supply. A recent study showed that the ingredients listed on the label of some herbal products are being replaced by cheaper substitutes such as rice and weeds.

This research, carried out at the University of Guelph and reported in the New York Timesthis week showed that over 1/3 of the 44 tested products contained none of the listed product as they had been entirely subsitituted with another filler. Some fillers were relatively innocuous such as rice powder, however some were potentially dangerous like walnut which could be deadly to those with nut allergies. Other substitutes included plants which cause rashes or laxative effects.

Some herbal medicines have stronger evidence behind them than others and one of the more beneficial is St. John’s wort which has been shown could be effective for mild depression. It was one of the herbal treatments tested which contained only rice powder and no St. John’s wort. In these cases the seriousness of the situation is underlined; a patient suffering from depression, rightly or wrongly, decides to self-treat with herbal medicine rather than conventional medicine and all they receive is a rice pill, allowing their depression to go entirely untreated.

The researchers used a DNA barcoding approach which can identify the presence of a species’ DNA. One of the potential drawbacks of the study is that it may not be able to detect DNA of labelled ingredients in cases where the material has been highly purified to remove traces of the DNA. This does raise the question though, if a product is highly processed and purified, at what point does the title herbal or natural cease to apply?

This study comes a few months after I wrote for Pharma IQabout ‘herbal’ medicines being sold online which were shown by the FDA to contain hydroxythiohomosildenafil which is similar to sildenafil, an ingredient in Viagra.

Since 1994 herbal medicines in the US have been relatively unregulated, only being pulled when harm could be demonstrated. The argument that they should be more tightly regulated raises an issue about perception. If all herbal medicines had to demonstrate that they contained nothing but the listed ingredient and that they were safe, it could lead to the perception that they are also effective. How would a member of the public know that a tightly regulated product with a stamp which could read ‘approved as safe by the FDA’ was no more effective than placebo?

One possible way around this which might be popular with those who oppose regulation might be to publicly name and shame those products or companies who routinely adulterate their products. One difficulty with this plan was demonstrated in the study, they did not disclose the names of the companies who failed their tests “To avoid singling out any company” which appears to be merely a cop-out to avoid potential litigation.

The fear is that this is a disaster waiting to happen and that it will take a disaster before anyone will intervene and do something about it.