Glucosamine May Not Have Long-term Benefits for Knee Pain
December 01, 2004
By: Steve Siwy for Knee1
A study recently concluded at the University of British Columbia has found no long-term benefits to the use of the supplement glucosamine in treating knee pain from osteoarthritis. According to the head of the study, Dr. Jolanda Cibere of the Arthritis Research Center (ARC) of Canada, this is the only study thus far to investigate glucosamine’s effectiveness for long-term pain control.
The University of BC study was conducted over the course of six months, and tracked the progress of 137 patients aged 44-48 years, all of whom had already been taking glucosamine for arthritis pain in the knee for an average of two years. One group was given glucosamine supplements, and another was given identical-looking placebos, with neither participant nor researcher knowing to which group the participant belonged (this is known as a “double-blind” study). Researchers then recorded each time a participant reported an arthritis “flare-up,” which was defined in the study as an increase in arthritis pain and reduction in activity.
Glucosamine is a large molecule found in joint cartilage. It plays a role in the production of collagen, as well as that of components of the synovial fluid that lubricates the knee. Osteoarthritis sufferers often take over-the-counter glucosamine supplements for the purpose of reducing swelling and pain in the joints. These supplements are usually either harvested from shellfish, or created synthetically (synthetic supplements are especially useful for those who have seafood allergies). Another supplement, chondroitin, is often paired with glucosamine, since it is another large molecule associated with healthy cartilage – naturally-occurring chondroitin inhibits the enzymes which normally break down cartilage.
Osteoarthritis is the result of inflammation and damage that occurs in the joints as the cartilage cushioning the bones degrades or wears away, and the bones begin to grind against each other. As the bones thicken and the leg-muscles weaken in response to the rougher operation of the cartilage-impoverished joint, the result is pain, stiffness, and joint instability.
The ARC study is not the first, of course, to examine the effectiveness of glucosamine for arthritis sufferers. Dr. Cibere told the Canadian Press, “Some studies have suggested benefit and other, more recent studies, have shown absolutely no benefit, similar to our study” According to the American Academy of Orthopaedic Surgeons (AAOS), glucosamine and chondroitin have been shown to relieve the pain of osteoarthritis, without having been seen to heal the loss of cartilage.
The results of the ARC study, the first, according to Cibere, to investigate the long-term benefits of glucosamine for osteoarthritis pain, show that arthritis flare-ups were virtually identical in those taking the supplement and those taking the placebo. 45% of those taking glucosamine “flared,” while 42% of those taking the placebo did. Thus, concludes the study, even if glucosamine was thought by the patient to be beneficial initially, no long-term benefit seems to be in evidence.
Currently, the National Institutes of Health (NIH) in the United States is conducting a study on the effects of glucosamine and chondroitin supplements, used separately and in conjunction, on patients with osteoarthritis. As of May 2004, the data from the Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT) were being analyzed, with the results to be published in a peer-reviewed medical or scientific journal. For now, the results of the ARC study offer something to think about for osteoarthritis patients, according to Dr. Cibere. “Even if people have initially perceived a benefit,” she said of glucosamine supplements, “I think that it is certainly prudent for patients to consider that they may not in fact benefit from taking it.”