Glucosamine and chondroitin may help in osteoarthritis

EDITOR—Several recent lay publications enthusiastically promote the benefits of glucosamine and chondroitin preparations in osteoarthritis.1 This has led to a surge of interest among patients and spectacular success in the marketplace; sales in the United States approach $1bn. The medical community has been reluctant to endorse these products, principally because of concerns about the quality of the evidence available from clinical trials.

Since the completion of our review, there have been several research developments. The issue of trial quality was recently reviewed by McAlindon et al.2 From 37 identified placebo controlled clinical trials of symptom relief in osteoarthritis with glucosamine and chondroitin preparations, 15 fulfilled predefined quality inclusion criteria for their meta-analysis. It was the authors' overall conclusion that the clinical trials demonstrated substantial effects on symptom relief in osteoarthritis, but that attendant methodological biases were likely to exaggerate the size of these benefits. The chondroprotective properties of glucosamine sulphate have been evaluated in two recent randomised controlled trials. 3 4 The data from each of these are currently available only as abstracts, but both studies show a significant reduction in joint space narrowing among patients receiving 1500 mg of glucosamine sulphate daily, compared with placebo, over three years of follow up. These agents are safe and are readily available to patients in health food shops and by mail order. As a consequence, they have great potential utility in the management of osteoarthritis, even if only modestly effective. Further data on efficacy and cost utility are eagerly awaited.