Adapted from New York Times
People have wildly conflicting opinions about the benefits of nutritional suppliments marketed for joint health. These include glucosamine, chondroitin, and MSM, short for methylsulfonylmethane. Vendors promise they lessen creaking and soreness of knees, backs, hips and other joints.
The results of scientific studies of the supplements are equivocal. In the largest study to date, published in 2006, more than 1,500 adults with knee osteoarthritis were randomly assigned to receive glucosamine, a painkiller or a placebo. After 24 weeks, only those participants taking the painkiller reported less knee pain. Glucosamine was no more effective than a placebo.
Two years later, 600 of the participants had continued to take glucosamine, painkillers or a placebo. There still was no obvious benefit from the glucosamine.
Oral suppliments are very different from viscosupplimentation, which is the scientific name for joint injections of similar nature to joint fluid. Those, although sometimes disputed, have a well documented record, and may help when other treatments, including steroids injections, have failed.
When asked about joint suppliments, I tell people that if they have already tried them and found some relief, it is OK to continue. I do not actively recommend nor suggest them to patients. The only serious side effects that I know of is spending money!