Review questions efficacy of tailored herbals
needs, is not supported by 'good evidence', a new review has
stated.
The paper, published in the Postgraduate Medical Journal , reviewed 1300 studies of the effectiveness of herbal medicines, and reports that only three studies were randomised controlled trials of sufficient quality to draw meaningful conclusions.
"Individualised herbal medicine, as practised in European medical herbalism, Chinese herbal medicine and Ayurvedic herbal medicine, has a very sparse evidence base and there is no convincing evidence that it is effective in any indication," wrote the authors from the Peninsula Medical School.
"Because of the high potential for adverse events and negative herb-herb and herb-drug interactions, this lack of evidence for effectiveness means that its use cannot be recommended," they added.
The UK is currently reviewing the law in relation to the regulation of tailored herbal medicinal treatments.
The reviewers, after trawling through the literature, report that the three randomised controlled trials of 'sufficient quality' covered knee osteoarthritis and irritable bowel syndrome (IBS), and the relief of side effects caused by drug treatment for cancer.
However, no statistical differences were observed between tailored herbal medicine and placebo in either the knee osteoarthritis study or the cancer treatment study, said the authors.
There was some evidence that the tailored herbal medicines were more effective than placebo in the IBS study, but they were still less effective than standard preparations.
"There is a sparsity of evidence regarding the effectiveness of individualised herbal medicine and no convincing evidence to support the use of individualised herbal medicine in any indication," concluded the reviewers.
In an accompanying editorial, Professor Edzard Ernst, co-author of the review, warned that the public is in danger of branding all herbal medicine the same.
Phytotherapy, which represents the scientific face of herbalism, is being confused with traditional herbal medicine and over the counter remedies, he said, which currently have no basis in science.
"Without these distinctions, we will fail to advance our knowledge of the potential benefits of herbal treatments.
More importantly, we will also fail in our foremost duty - to protect the public from treatments that cause them harm," he concluded.
Commenting independently on the review, Alison Denham from the National Institute of Medical Herbalists told the BBC that it was impossible to draw conclusions from three small studies with "questionable methodology".
"These treatments really can make a difference to people's health - that's why they have been used for such a long time," said Denham.
"People often come to us having gone down the orthodox road with no luck, and find something that works for them.
"But there are certainly issues around the expertise of practitioners which need to be addressed, and we look forward to government regulation which imposes a high standard of training on anyone who wants to register," she added.
A report published last year in the New England Journal of Medicine held that use of herbal medicines in the UK is amongst the lowest in Europe, and few GPs prescribe them.
At the other end of the scale German health insurance providers reimbursed US$283 million for prescriptions of ginko, St John's wort, mistletoe, saw palmetto, ivy, hawthorn, stinging nettle root, myrtol, phytosterols and curcurbita in 2003.
French insurers paid out $91 million in partial reimbursements for ginko, saw palmetto and pygeum, with a total value of $196 million.
Almost $5 billion (at manufacturers' prices to wholesalers) was spent on over-the-counter herbal medicines in all European countries in 2003.
Source: Postgraduate Medical Journal Volume 83, Pages 633-637.
Doi: 10.1136/pgmj.2007.060202 "A systematic review of randomised clinical trials of individualised herbal medicine in any indication" Authors: R Guo, P H Canter, E Ernst Editorial:
Postgraduate Medical Journal Volume 83, Pages 615-616.
Doi: 10.1136/pgmj.2007.060780 "Herbal medicine: buy one, get two free" Author: E Ernst
