Jury Still Out on Use of Supplements to Treat Arthritis
March 14, 2000 (Washington) -- True or false: Dietary supplements containing glucosamine and chondroitin are attractive alternatives to anti-inflammatory drugs for treating osteoarthritis (OA). True, says an analysis in the Journal of the American Medical Association (JAMA), the first professional American journal to review the value of these "natural" remedies. But you might not want to rush out and buy a lifetime supply just yet.
The JAMA analysis is based on an assessment of 15 previously published studies that have been highly criticized. And while it eliminates several factors that may have contributed to their potentially flawed results, it still fails to demonstrate the true risks or benefits of using these supplements, some experts warn.
The effects found in these earlier studies, which were primarily sponsored by manufacturers, are exaggerated, concedes Timothy McAlindon, DM, an author of the JAMA article. He says that further studies are needed to determine the supplements' exact benefits in treating OA. Nevertheless, they do appear to work to some degree, McAlindon says.
But for whom and how long? And are they safe for everyone? These are the questions the analysis fails to address, say Tanveer Towheed, MD, MS, and Tassos Anastassiades, MD, PhD, both of Queen's University in Ontario, who reviewed the study in an accompanying editorial.
About 21 million Americans 25 and older suffer from OA, but the analysis does not clarify who will most benefit from the supplements. It does not specify the ages or genders of the study participants, or the severity of their conditions, and does not determine whether any were using additional medications to treat OA, Towheed and Anastassiades say.
On top of all that, it does not compare side effects of the dietary supplements to those of prescription drugs approved for treating the condition, "making it difficult to evaluate whether the risks are worth the benefits," they note. And it fails to account for the fact that manufacturers make the compounds in varying degrees of purity and content, which may affect the degree of benefits and side effects, they say.
Glucosamine and chondroitin include important components of the body's natural building blocks for the cartilage found in joints, and therefore may play a large future role in treating OA, Towheed and Anastassiades say. But until high-quality, long-term studies are done, enthusiasm for these compounds should be tempered with a healthy dose of skepticism.