Meta-Analysis on Glucosamine and Chondroitin Stirs Controversy

A new meta-analysis on glucosamine and chondroitin supplements has determined that the joint health ingredients “do not reduce joint pain or have an impact on narrowing of joint space.” The meta-analysis, published last week at the British Medical Journal, included ten large scale trials with a total of 3803 patients. It was supported by grants from the Swiss National Science Foundation’s National Research Program.

But industry organizations, including the Council for Responsible Nutrition (CRN; Washington, DC), are saying the meta-analysis had serious limitations.

Researchers took to the meta-analysis based on the notion that results from trials on the two ingredients have been conflicting. Large scale, randomized, controlled trials using more than 200 patients with knee or hip osteoarthritis were considered eligible for the meta-analysis and joint pain and narrowing of joint space were markers used to assess joint health.

“For none of the estimates did the 95% credible intervals cross the boundary of the minimal clinically important difference,” wrote the study’s lead author. Another determination made in the analysis was that commercially funded trials showed greater benefits from the ingredients over industry-independent trials.

“Compared with placebo, glucosamine, chondroitin, and their combination do not reduce joint pain or have an impact on narrowing of joint space,” wrote the lead author, adding that health authorities and insurers should not cover the costs for these ingredients. The meta-analysis, however, concluded that glucosamine and chondroitin ingredients were perceived as safe, and patients might want to consider supplementation for placebo effect.

Industry Response

While Nutritional Outlook expects thorough response to the meta-analysis from industry organizations, CRN has already provided some feedback for us.

The organization states that on top of previously-published meta-analyses on chondroitin and glucosamine which show positive signs, this new meta-analysis has limitations.

“The investigators excluded randomized controlled trials (RCTs) involving less than 100 subjects or studies with lower doses,” said Andrew Shao, MD, senior vice president of scientific and regulatory affairs at CRN. “Of the 58 reports they identified in the literature, they included data from only 10 RCTs, conveniently excluding a large portion of the evidence base. Furthermore, they combined studies with different designs and pre-specified outcomes which are really not combinable in a meta-analysis, i.e. they are too dissimilar.”

Pharmaceutical-grade glucosamine and chondroitin is also available and approved in various European countries, noted Shao.