Popular Joint Pain Supplements Do Not Help Relieve Symptoms

A new study claims that glucosamine and chondroitin, two supplements commonly used to reduce pain in patients with osteoarthritis (OA) in the knees and hips, do not actually relieve symptoms.

Researchers the University of Bern (Switzerland) examined the results of ten published trials involving 3,803 patients that studied the effects of glucosamine, chondroitin, or their combination, on pain caused by OA of the knee or hip. Direct comparisons within trials were combined with indirect evidence from other trials by using a model that allowed the synthesis of multiple time points. The main outcome measure was pain intensity; secondary outcome was change in minimal width of joint space. The minimal clinically important difference between preparations and placebo was prespecified at -0.9 cm on a 10 cm visual analogue scale (VAS).

The results showed that the overall difference in pain intensity compared with placebo was -0.4 cm for glucosamine, -0.3 cm for chondroitin, and -0.5 cm for the combination. For none of the estimates did the 95% credible intervals cross the boundary of the minimal clinically important difference. The results also showed that industry independent trials showed smaller effects than commercially funded trials. The differences in changes in minimal width of joint space were all minute, with 95% credible intervals overlapping zero. The study was published in the September 16, 2010, issue of the British Medical Journal (BMJ).

"We see no harm in having patients continue these preparations as long as they perceive a benefit and cover the cost of treatment themselves,” said lead author Professor Peter Jüni, Ph.D., of the Institute of Social and Preventive Medicine at the University of Bern. "However, 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.”

Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids, and is one of the most common nonvitamin, nonmineral, dietary supplements used by adults. Chondroitin sulfate is a sulfated glycosaminoglycan (GAG) composed of a chain of alternating sugars, and is an important structural component of cartilage, providing much of its resistance to compression. Along with glucosamine, chondroitin sulfate is a widely used dietary supplement for treatment of OA.

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