Researchers call for independent testing of herbal medicines
Australians may be putting their health at risk by using potentially dangerous “natural” herbal remedies, researchers have warned.
Lack of regulation, the inclusion of unidentified ingredients – some illegal or even toxic – and the mistaken belief that “natural” means “safe” were just some of the perils, the authors wrote in the Medical Journal of Australia.
With 69 per cent of Australians estimated to use complementary medicines, and more than half of those not telling their doctors, there was a risk of unwanted side effects and dangerous interactions with prescribed medicines.
“Rather disturbingly, the answer to the question – ‘What are the risks to the Australian community from herbal products?’ – is that we simply do not know,” the authors, led by Professor Roger Byard, chair of pathology at the University of Adelaide, said.
The authors called for the Therapeutic Goods Administration (TGA) to consider requiring manufacturers to have samples independently tested.
The lack of reported side effects in traditional societies has often been cited as evidence of the safety of herbal products, the researchers said.
But a lack of systematic observation meant that even serious adverse reactions, such as kidney failure and liver damage caused by plants from the Aristolochia species, extracts of which are used in some herbal weight loss and joint pain relief formulations, were unrecognised until recently.
The researchers warned of several potential dangers, including:
- adulteration with pharmaceutical agents, ‘presumably added to increase the apparent efficacy of the herbal product’, exposing users to the risks of ingesting uncontrolled amounts of these drugs, of allergies to undisclosed ingredients such as antibiotics, and of interactions with prescribed medications;
- substituted plant ingredients, which may be deliberate if the original plant is difficult to obtain or expensive, or the result of misinterpreting or inaccurately transcribing names or formulas in texts;
- the presence of toxic substances, from both animals and plants, as well as heavy metals and pesticides;
- inadequate processing; and
- pharmaceutical interactions, with herbal medicines potentially enhancing or reducing the effects of prescribed medications, or eliciting unpredictable idiosyncratic effects.
“It may be appropriate for the TGA to require manufacturers to have samples independently tested before placing them on the market,” the researchers said.
“Legal action should be considered in cases of non-compliance with applicable regulations, and preparations containing illegal substances should be banned.”
But the peak body representing complementary medicine producers and importers said that products on the Australian market already met stringent tests, and the problem arose from products purchased online from overseas.
“Australia has some of the most stringent regulations in the world for herbal products, as for all complementary medicines on the Australian market,” Complementary Medicines Australia (CMA) chief executive officer Carl Gibson said.
“Products are required to be entered on to the Australian Register of Therapeutic Goods (ARTG), which is maintained by the TGA. Unless entered on the ARTG, these products cannot be legally imported, exported, manufactured or supplied to consumers in Australia.
“Concerns raised by the authors, such as adulteration with pharmaceutical agents, inadequate processing, and the presence of toxic substances, have been known to affect products purchased online from overseas, which are not subject to the same regulations as those enforced in Australia.”
Online purchases of complementary medicines should only be made on the recommendation of a qualified healthcare professional, or from a known and reputable source, Mr Gibson said.
Published: 10 Feb 2017