One of the most popular supplements for joint health, chrondroitin is taken by over seven million Americans according to the Natural Products Association (NPA).
The meta-analysis - which was led by Stephan Reichenbach from the University of Bern - reviewed 20 studies using the compound, but based its conclusion on three studies.
This methodology drew criticism from the dietary supplements industry after the meta-analysis maintained chondroitin has the same effect as placebo for osteoarthritis in the hip and knee.
One of the many companies with a vested interest in any negative publicity on chondroitin, Bioiberica, issued a statement on the meta-analysis.
"The parameter used in this study is pain, but it should be borne in mind that chondroitin sulfate is not an analgesic," said Dr. Josep Verges, scientific director with Bioiberica, "Specifically, chondroitin sulfate presents an anti-inflammatory effect, which in turn results in pain reduction."
Verges drew attention to the Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) referred to in the meta-analysis.
"At the same time, in the GAIT trial, also cited by the authors as one of the recent, large-scale trials on chondroitin sulfate, the patients in the chondroitin sulfate group presented a statistically significant improvement on joint effusion/swelling, thus evidencing an effect on inflammation," said Verges in the statement.
Chondroitin sulphate is extracted from animal cartilage like shark cartilage.
It is increasingly combined with glucosamine for joint health.
"It's important to keep in mind that most consumers use a combination of glucosamine and chondroitin, not just chondroitin by itself," said NPA's VP of scientific affairs, Daniel Fabricant.
According to the Nutrition Business Journal, US sales for these combined supplements were $810 million in 2005.
Reichenbach and other researchers from the University of Bristol and the University of Gottingen, searched through four scientific databases and selected randomized or quasi-randomized studies.
They drew on 20 trials consisting of 3846 participants.
However, the results were heterogeneous, said the researchers, so they restricted their analysis to only three.
"NPA reviewed the analysis and found that, among other things, no distinction was made between mild, moderate and severe osteoarthritis, which all involve very different treatment regimens," said Fabricant.
Bioiberica supplies chondroitin as part of its Bio-active ingredient line, which also includes glucosamine and sodium hyaluronate.
"Obviously, a better knowledge of the osteoarticular pathology to understand underlying mechanisms of osteoarthritis, a better or worse response on pain, etc, as well as ongoing clinical trials will provide more knowledge on this issue," said Verges.
Source: Annals of Internal Medicine Volume 146, Pages 580-590 "Meta-analysis: Chondroitin for osteoarthritis of the knee or hip" Authors: S. Reichenbach, R. Sterchi, M. Scherer, S. Trelle, E. Burgi, U. Burgi, P.A. Dieppe, P. Juni