Researchers from the University of Utah carried out two-year study on the participants with 500 mg of glucosamine three times a day; or 400 mg of chondroitin sulfate three times a day; or a combination of the two supplements; or 200 mg of celecoxib daily; or a placebo.
They obtained X-rays at study entry and again at one and two years. Joint space width was measured on 581 knees from 357 patients. The results found that the group taking glucosamine had the least change in joint space width, followed by the groups taking chondroitin sulfate, celecoxib, placebo and the combination of both dietary supplements.
The combination glucosamine chondroitin is the sixth-top-selling dietary supplement in the U.S. They results determined no single treatment showed what appeared to be a clinically important reduction in joint space width loss.
Researchers had trouble determining their results because patients who took placebos had a smaller loss of cartilage than they should have. The results were published on the website of the journal Arthritis & Rheumatism.
