Leading figures from the natural health sector in Britain and America have questioned the findings of a survey into the effectiveness of glucosamine and chondroitin. The British Medical Journal (BMJ) has published a study by professor Peter Jüni and his team at the University of Bern who found no “clinically relevant effect” of glucosamine or chondroitin. The Bern team’s conclusion was based on a meta-analysis of 10 published trials.

The report’s authors wrote: “Compared with placebo, glucosamine, chondroitin, and their combination do not reduce joint pain or have an impact on narrowing of joint space. They added: “Health authorities and health insurers should be discouraged from funding glucosamine and chondroitin treatment.”

But natural health experts have pointed out that the Swiss team “left out” many of the previously published trials that have produced positive findings for both glucosamine and chondroitin.

Commenting on the meta-analysis, the executive and scientific director of the Alliance for Natural Health (ANH), Robert Verkerk, said: “The type of meta-analysis used is a classic case of throwing a whole bunch — in this case 10 — of different trials into the mixing pot and ending up with an average result that dilutes out the positive results. These trials, amongst other things, involve different forms of glucosamine, different severities of condition and different supplementation periods, You could say it’s a case of apples and oranges, but where you’re only interested in apples but you’ve completely mixed up your apples and oranges!”

The ANH points out that the Berne scientists failed even to mention a 2003 piece of work by a Belgian research group published in the Archives of Internal Medicine that found the complete opposite of the analysis in the BMJ. The authors of the Belgian study (Richy and colleagues) concluded: “Our results demonstrated a highly significant efficacy of glucosamine on all outcomes, including joint space narrowing and WOMAC” (a pain assessment scale used to measure joint pain). There has been a similar reaction to the Swiss survey in the United States. Andrew Shao, PhD, senior vice president of scientific and regulatory affairs for the Council For Responsible for Nutrition, said the analysis suffered from a number of limitations. He told Natural Foods Merchandiser magazine that the researchers used studies with less than 100 subjects as well as those using lower doses of glucosamine and chondroitin. By using only 10 studies they had “conveniently excluded a large portion of the evidence base”.

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