According to a new analysis of 10 studies led by Professor Peter Jüni at the University of Bern in Switzerland, these supplements do not work.
The researchers assessed changes in levels of pain after patients took glucosamine, chondroitin, or their combination with placebo or head to head.
They found no clinically relevant effect of chondroitin, glucosamine, or their combination on perceived joint pain. A follow-up arm of this study showed that they did not do any better than placebo in slowing loss of cartilage that occurs in OA of the knee.
However, analysis of a smaller subset of patients with moderate-to-severe osteoarthritic pain demonstrated that combination therapy significantly decreased knee pain related to OA.
The mean age of the 3,803 patients involved in these studies was 59 years, and 64 percent were women.
OA of the hip or knee is a chronic condition which is mainly treated with painkillers and anti-inflammatory drugs but these can cause stomach and heart problems, especially if used long-term.
In the last decade, GPs and rheumatologists have increasingly prescribed glucosamine and chondroitin to their patients. And many individuals around the world have purchased them over the counter. In 2008 global sales of glucosamine supplements reached almost US$2bn, which represents an increase of about 60% since 2003.
The supplements are safe and there is no harm in having patients continue these preparations as long as they perceive a benefit, the study researchers write.
Journal Reference:Simon Wandel, Peter Jüni, Britta Tendal, Eveline Nüesch, Peter M Villiger, Nicky J Welton, Stephan Reichenbach, Sven Trelle. Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of the hip or knee: network meta-analysis. British Medical Journal, 2010; DOI: 10.1136/bmj.c4675
Now, let's have the reactions of key medical specialists and scientists to this analysis.
WebMD Health News on Sept 16, 2010 reported :
"If you want to take them and perceive a benefit, that's fine, but tell your doctor," says David Pisetsky, MD, chief of rheumatology at Duke University Medical Center in Durham, N.C. Pisetsky does have a number of patients who take, and will likely continue to take, these supplements.
Jason Theodosakis, MD, an assistant clinical professor at the University of Arizona College of Medicine in Tucson, and the author of several books that on the supplements, is unwavering in his support of their use in OA. He points out that there have been many positive studies, and there have been some major flaws with the design of the negative studies -- including the new analysis.
"The safety of these supplements has never been doubted," he says in an email. "You have to ask yourself, would you take a supplement containing glucosamine and chondroitin, have about two-thirds of a chance of getting significant relief, with some evidence that you can slow your disease progression, or just numb your symptoms with paracetamol anti-inflammatory drugs and risk ulcers, allergies, kidney or liver damage, hypertension, heart attacks and possibly death." These are some risks that have been associated with prescription and over-the-counter painkillers.
"The risk/benefit for glucosamine and chondroitin far outweighs that of the FDA-approved drugs for osteoarthritis," he says.
Marc C. Hochberg, MD, MPH, professor of medicine and head of the division of rheumatology and clinical immunology at the University of Maryland School of Medicine in Baltimore, points out that the statistical techniques used in the new study were really not designed to be applied to groups, which may cast some doubt on the way the findings are being interpreted.
"These supplements did have a very small effect," he says. "This effect was very similar or identical to what is seen with acetaminophen, which is the first line treatment of OA according to the American College of Rheumatology and other professional organizations."
His advice? "If patients want to use glucosamine, then they should discuss this with their physician who may recommend a particular brand and manufacturer."
AndrewShao, PhD, senior vice president of scientific and regulatory affairs at the Council for Responsible Nutrition, a trade group representing supplement manufacturers, points out that the majority of published studies involving glucosamine and/or chondroitin are positive.
"We also must recognize that consumers have voted with their wallets -- choosing to continue to derive benefits from glucosamine and chondroitin supplements, with the category experiencing significant year over year growth over the past decade," he says in an email. "If these were ineffective, then we would not observe this kind of growth."
Finally, he says, the safety of these supplements is well recognized.Photo : Viartril-S Capsules by Rotta