Letter to The Guardian…
by Jim Caryl
A little long, didn’t fly, but better luck next time.
[Guardian, Tuesday 31st April] Cherill Hicks article, ‘Not to be sneezed at’, gave a timely and largely useful revision of therapies available to hay fever sufferers, but tripped up by suggesting that research on homeopathic treatments was ‘encouraging’.
It is still the consensus in the scientific literature that homeopathy does not perform any better than placebo, an issue which has been addressed by a comprehensive study by Aijing Shang MD and colleagues at the University of Berne, Switzerland. The study, published in The Lancet (2005), compared 110 homeopathy trials with 110 conventional medicine trials, and found that conventional medicines work, with little evidence to say the same of homeopathic medicines.
The positive findings of a few placebo-controlled trials of homeopathic medicines are cherry picked from a mountain of contradictory results, and are generally found to result from combinations of methodological deficiencies and biased reporting. The ‘encouraging’ results for treatment of hay fever with Galphimia glauca arise from a series of studies by a single homeopathy research group, and have been given unwarranted kudos in homeopathy circles due to the publication of a meta-analysis, which is an analytical over-view of combined results from numerous methodologically similar studies.
However, the meta-analysis only consists of seven trials (included in the Lancet study by Dr Shang and colleagues), and all come from the same research group; indeed, the group leader was a co-author on the meta-analysis itself. There are insufficient data from independently reproduced studies to corroborate the positive findings for Galphimia glauca as a treatment for hay fever, thus its status as a recommendable therapy is dubious.