Jury Still Out on Use of Supplements to Treat Arthritis
By
Ori Twersky
WebMD Medical News |
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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.
The good news for consumers is that at least one such study has already been initiated. In September 1999, the National Institutes of Health funded a study to investigate the efficacy and safety of glucosamine and chondroitin for the treatment of OA in the knee. Researchers are expected to begin recruiting patients for the 16-week study later this year.
In the meantime, what is a patient who suffers from the side effects of prescription anti-inflammatory drugs to do?
"I recommend that they take [the supplements] for a minimum of 12 weeks to see if they're going to have a therapeutic effect," says Marc Hochberg, MD, MPH, a professor and chairman of rheumatology at the University of Maryland.
But then there still is that potential downside. Because dietary supplements are not regulated to the same degree as prescription drugs, "when you go into the store, you're not sure what you're getting," Hochberg says.
Vital Information:
Supplements containing glucosamine and chondroitin may be beneficial in treating osteoarthritis, although previous studies sponsored by manufacturers may have overstated their efficacy. Researchers are still uncertain about the side effects of these supplements or how they compare to approved prescription medications. Osteoarthritis patients who suffer side effects from their medication can try glucosamine and chondroitin for a minimum of 12 weeks to determine whether the supplements work for them, one expert says.
