Don't pay for joint supplements, insurers told

Doctors should be discouraged from prescribing two popular supplements, glucosamine and chondroitin, for osteoarthritic hips and knees, researchers conclude.

A review analyzed the results of 10 published studies involving more than 3,000 patients with knee or hip osteoarthritis. Study participants took glucosamine, chondroitin, or both, and all studies used a placebo. 

Prof. Peter Juni, head of the Institute of Social and Preventive Medicine at the University of Bern in Switzerland, and his colleagues concluded the supplements are not dangerous for joint pain — but they do not work.

"We see no harm in having patients continue these preparations as long as they perceive a benefit and cover the cost of treatment themselves," researchers wrote in Friday's online issue of BMJ.

"Health authorities and health insurers should not cover the costs for these preparations, and new prescriptions to patients who have not received treatment should be discouraged," the authors added.

For the past decade, some doctors have recommended glucosamine and chondroitin to treat arthritis pain in the hip or knee.

The supplements are components of human connective tissues found in cartilage and bone.

Worldwide, sales of glucosamine supplements reached almost $2 billion US in 2008, up about 60 per cent since 2003, the researchers said.

But the results of randomized trials on the effectiveness of the supplements were conflicting, the researchers said in explaining why they conducted a large-scale review.

The researchers found no clinically relevant effect of chondroitin, glucosamine, or their combination on perceived joint pain or on joint space narrowing.

It is up to patients to decide whether to continue taking the supplements, said Jane Tadman, a spokeswoman for the charity Arthritis Research U.K., which was not involved in the research.

"Some people may want to consider an over-the-counter trial as part of a wider self-management plan which includes exercise and keeping to an ideal weight," Tadman said.

The study was paid for by the Swiss National Science Foundation.