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
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
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.