Herbal medicines may be harmful, review finds
Individualised herbal medicine has almost no evidence base and may be harmful for patients, says the author of a recent review on the subject.
The systematic review, published in the Postgraduate Medical Journal, looked at 1345 randomised and controlled studies of individualised herbal treatments – where a mixture of herbs is tailored for each patient – and analysed their methodological quality. They found only three clinical trials which were robust enough to be included in the analysis.
Of these three studies, only one showed that individualised herbal treatments were better than placebo. In this study, the Chinese individualised herbal treatment for irritable bowel syndrome was still shown to be inferior to standardised Chinese herbal treatment. The review concluded that there was 'no convincing evidence' supporting the use of individualised herbal medicines in any indication.
Dr Peter Canter, research fellow in complementary medicine at the Peninsula Medical School, said that individualised herbal medicine had a number of known risks but "paltry" evidence for clinical benefit.
'If it was a new pharmaceutical it would not be allowed before its efficacy was demonstrated,' said Dr Canter. 'But for these treatments the risks are well-known but [herbalists] are borrowing evidence that doesn't apply.' Contamination, herb-drug interactions and the lack of regulation of herbalists could present dangers for patients, he said. 'Can they recognise a red flag symptom of a serious disease or a serious adverse event?'
Jay Mackinnon, accreditation officer for the National Institute of Medical Herbalists, dismissed the study. 'This isn't a particularly substantial paper, as it is an analysis of three papers,' she said. 'There is no evidence here that individualised herbal medicine doesn't work.'Herbal Medicines