Glucosamine and chondroitin for knee osteoarthritis Original paper

Glucosamine and chondroitin are popular supplements taken with the goal of improving joint health in osteoarthritis. The hypothesis that these compounds might be of benefit is based on their role as precursors to several glycoproteins that are known to lubricate joints and reduce friction. However, the efficacy of glucosamine and chondroitin for osteoarthritis remains controversial.

This 4-week randomized controlled trial examined the effect of glucosamine and chondroitin supplementation on osteoarthritis when added to exercise and physical therapy. A total of 24 participants (average age of 57; 75% men, 25% women) with nonsevere osteoarthritis (OA) of the knee were recruited and were assigned to take 500 mg of glucosamine and 400 mg of chondroitin sulfate or a placebo three times per day.

During the trial, all participants underwent exercise and physical therapy, which involved applying a hot pack to their knee for 20 minutes (three times per week), joint mobilization (three times per week, after hot pack use), 5–10 minutes of pain-free walking (seven times per week), and light lower-body resistance exercise (seven times per week, after walking).

The outcomes included pain (measured via visual analog scale), the Knee injury and Osteoarthritis Outcome Score (KOOS; a measure of OA symptom severity), and range of motion.

Glucosamine and chondroitin supplementation had no apparent effect on pain, symptom severity, or range of motion.

Both groups experienced similar improvements in pain and symptoms during the trial, potentially (although not necessarily) indicating a benefit from the exercise and physical therapy.