Homeopathic remedies produce an effect that is largely in the mind, according to a study published in international medical journal the Lancet.
The findings were yesterday challenged by advocates of homeopathy in this country.
In the study, Swiss scientists compared the results of 110 trials using homeopathic remedies, with the same number using conventional medicines across a range of medical conditions from respiratory infections to surgery.
The study found that homeopathy had no more than a placebo ("sugar pill") effect.
In a strongly worded editorial entitled "The End of Homeopathy", the journal called on doctors to be "bold and honest" with their patients about the absence of curative powers in homeopathy and with themselves for the failings of modern medicine to address patients' needs for personalised care.
However, the findings have been strongly challenged by advocates of homeopathic medicine in Ireland.
In a statement last night, the Irish Society of Homeopaths said the authors of the study had used a "misguided measure with which to assess the efficacy of homeopathy".
Homeopathy was developed over 200 years ago by Samuel Hahnemann, a German doctor and chemist, who believed that disease was an indicator that the body was out of balance. He argued that this could be put right by application of the principle that "like cures like".
According to the theory, a tiny dose of whatever was the source of the problem, diluted strongly with water, would stimulate the body into combating it.
Homeopathic remedies are tailored to the individual, whose emotional state and temperament, as well as physical condition, are taken into account.
For many doctors and scientists, the problem with homeopathy is that the remedies are diluted to such a degree they are considered unlikely to have any effect. Conventional medicine has long argued that any consequence generated is coincidence or the placebo effect.
Homeopathic practitioners have argued that even if the remedy contains little of the original substance, the solution continues to hold a "trace memory" which can mobilise the body.
The study, which was carried out by a team from the University of Berne, led by Prof Mattias Egger, and found that homeopathic remedies were more likely to have had a positive effect in smaller trials. In the larger trials, the study found that homeopathy was no better than a placebo.
"We acknowledge that to prove a negative is impossible, but we have shown that the effects seen in placebo-controlled trials of homeopathy are compatible with the placebo hypothesis," Prof Egger said.
The Irish Society of Homeopaths said many previous studies had demonstrated that homeopathy had an effect over and above placebo.
