In the April 16th edition of the Annals of Internal Medicine, a chondroitin meta-analysis was published. Data was synthesized from 20 trials, however, only three made the final cut due to the heterogeneity of some trials, which made the interpretation of results difficult. In the end, based on three trials, the authors concluded that large-scale, methodically sound trials indicate that the symptomatic benefit of chondroitin is minimal or non-existent. They therefore discouraged the use of chondroitin in routine clinical practice.

In response to this meta-analysis, the Council for Responsible Nutrition (CRN), Washington, D.C., reminded consumers that chondroitin is a safe, affordable and beneficial option for helping maintain mobility and reduce discomfort associated with osteoarthritis, particularly when combined with glucosamine.

According to Andrew Shao, PhD, vice president, scientific and regulatory affairs, CRN, “Meta-analysis can be a valid tool for scientific evaluation, but it also has recognized limitations. One can include and exclude studies in various combinations, but the bottom line is consumers use glucosamine and chondroitin supplements because they work.”

The meta-analysis could have potentially included approximately 300 scientific reports on chondroitin; but the researchers chose to look only at 20 randomized clinical trials. Of those 20 trials, they excluded all but three, advising they selected those three they believed were of the highest quality. In effect, CRN feels they excluded the majority of the data to reach the conclusion that chondroitin worked no better than placebo.

In an editorial accompanying the meta-analysis in the Annals of Internal Medicine, David Felson, MD, MPH, Boston University and Boston Medical Center, who agrees with the conclusions reached by the authors with regard to chondroitin, closes with the statement, “If patients say that they benefit from chondroitin, I see no harm in encouraging them to continue taking it as long as they perceive a benefit.”

CRN’s Dr. Shao explained, “As much as we would like for science to always give us clear answers in black and white, the fact is, science is open to interpretation. Although meta-analysis can be a useful tool to examine results from multiple trials, it is still just one tool, and in this case focused on only a narrow view of the entire body of evidence on the effect of chondroitin supplementation. People want to do what works for them, and for many people, that’s taking glucosamine and chondroitin supplements.”

David Mark, PhD, an industry consultant who has a variety of clients in the joint health arena, said he read the coverage of the chondroitin meta-analysis in The New York Times and considered it to be well balanced. “It acknowledged that some studies have reported a benefit, and that the authors of this new review focused on three recent large studies that did not,” he commented. “Furthermore, the Natural Products Association was given an opportunity to comment and it pointed out that chondroitin is almost always taken with glucosamine, that the combination has a benefit, and that there are limited alternatives for osteoarthritis sufferers.”

Dr. Mark also said the study everyone should really be paying attention to is the second phase of GAIT. “I expect a conference presentation in either late 2007 or early 2008,” he said, adding, “In the second phase, half of the subjects continued with the study for an additional 18 months and were assessed at six-month intervals for pain relief, function and joint space narrowing.”

In a letter released by Dr. Josep Verges, MD, MSc, PhD, professor of Pharmacology at the University of Madrid, and scientific director of Bioiberica, Madrid, Spain, following publication of the meta-analysis, it was pointed out that while the parameter used in the study was pain, people should keep in mind that chondroitin sulfate is not an analgesic. Rather, Dr. Verges said, “Chondroitin presents an anti-inflammatory effect that results in pain reduction and improvement in joint function.”