Chondroitin No Help for Arthritis Pain
Popular Supplement No Better Than Sugar Pill, Large Studies Show
WebMD News Archive
April 16, 2007 -- Chondroitin, a dietary supplement, works no better than a sugar pill, analysis of clinical data suggests.
In the U.S., chondroitin is almost always combined with glucosamine, another supplement. Annual U.S. sales of the chondroitin/glucosamine combination were $810 million in 2005, according to figures cited by the Council for Responsible Nutrition (CRN), a supplement industry trade group.
And sales "continue to grow at a phenomenal pace," Andrew Shao, PhD, the CRN's vice president for scientific and regulatory affairs, tells WebMD. Shao says only omega-3 supplements sell faster than chondroitin-based supplements.
"Sales continue to grow. This is presumably because consumers are finding a benefit," Shao says.
That benefit appears to be an illusion, suggests Peter Juni, MD, head of clinical epidemiology and biostatistics at the University of Bern in Switzerland.
David T. Felson, MD, MPH, professor of medicine and epidemiology at Boston University, uses stronger language.
"What WebMD readers should take home about the possible efficacy of chondroitin is that it doesn't work," Felson tells WebMD. "The confusion is there was some early evidence suggesting it does work. The better evidence suggests it does not."
Juni's study, and Felson's accompanying editorial, appear in the April 17 issue of Annals of Internal Medicine.
Chondroitin Zero Benefit
Chondroitin usually comes from animal cartilage. People with osteoarthritis lose cartilage in their joints. Researchers disagree over whether chondroitin taken by mouth ever finds its way to the joint. They also disagree over whether it offers any benefit to people with arthritis.
Juni and colleagues analyzed every clinical study of chondroitin as a treatment for arthritis. The studies focused on chondroitin alone and not in combination with glucosamine.
Early clinical trials showed a fabulous benefit for chondroitin -- in one case finding the supplement was more effective than knee replacement surgery. A close look showed many kinds of problems with these early trials. Three more recent trials avoided these problems.
"Early, methodologically insufficient trials showed overoptimistic benefits for chondroitin," Juni tells WebMD. "The longer people evaluated the drug, the better they evaluated it, the worse the drug looked. In the last few years, large trials showed effects that were nearly or entirely null. It is likely these trials show a reliable estimate of the benefit of this drug, which is zero."