Friday, Oct. 31, 2008; 11:26 AM

Some studies have suggested benefits of glucosamine and chondroitin for people with osteoarthritis — the most common type of arthritis. However, these investigations looked at each supplement separately, and the two are typically sold in combination, Dr. Allen D. Sawitzke of the University of Utah in Salt Lake City and colleagues note.

In the current study, which is the first to look at the combined effects of the two supplements, Sawitzke and his team randomly assigned 572 patients with osteoarthritis of the knee to 500 mg of glucosamine 3 times a day, 400 mg of chondroitin 3 times a day, glucosamine plus chondroitin, 200 mg daily of celecoxib (sold in the US as Celebrex), or placebo.