Medical experts have called for vitamins and supplements sold in Australia to be independently tested, saying many people could be unwittingly causing themselves harm.
A review of complementary medicines by the University of Adelaide, Murdoch University and Curtin University concluded that most Australians see herbal products as harmless.
However, experts writing in the Medical Journal of Australia said some herbal remedies sold on the Australian market could contain chemicals, natural toxins, heavy metals or pesticides.
The researchers found the regulation of herbal products in Australia remained relatively lax, and that the content and quality of drugs were not as tightly controlled as standard pharmaceuticals.
“A significant number of traditional herbal medicines do not comply with Australian regulations,” said the review’s co-author, Ian Musgrave from the University of Adelaide.
“In some cases, ingredients are either not listed or their concentrations are recorded inaccurately on websites or labels.
“Most worryingly, a few products are illegally adulterated with standard pharmaceuticals to increase the effectiveness of the herbal product.”
The researchers found one man suffering from epilepsy took a Chinese herb that was purported to treat seizures naturally.
However, the product was laced with the anticonvulsant phenytoin, and the patient nearly died from having toxic levels of the medication in his blood.
In a separate incident, a young boy was given Tibetan herbal vitamins by his parents.
The pills were later found to contain dangerous levels of lead, and the boy had consumed 63 grams of the toxic metal over four years.
Herbal medications can cause complications
The study’s lead author and University of Adelaide professor Roger Byard said even herbal medications that did not contain toxic chemicals or secret ingredients could cause complications such as kidney failure or liver damage.
“The lack of systematic observation has meant that even serious adverse reactions caused by some plant species have gone unrecognised until recently,” he said.
Last year, the ABC reported that a West Australian man nearly died after taking protein powder containing green tea extract and a supplement with garcinia cambogia.
Doctors believe the green tea extract caused Matthew Whitby’s liver to fail.
Two weeks from death, he had to accept a donated liver with Hepatitis B. He will now have to take a raft of medications for the rest of his life.
Chinese medicine Chan Su laced with toad venom
The researchers warned that Chan Su — a popular Chinese medicine used for skin and throat infections — is sometimes laced with toad venom.
The poisonous secretion of Asian toads is known to cause seizures, arrhythmias and even comas.
“We feel it would be appropriate for the Therapeutic Goods Administration (TGA) to require manufacturers to have samples independently tested before placing them on the market,” Professor Byard said.
“Legal action should be considered in cases of non-compliance, and preparations containing illegal substances should be banned.”
The researchers also want the more controversial herbal products sold in Australia to carry warning labels.