Studies show chondroitin does nothing for arthritis pain

In another blow to those who swear by chondroitin for arthritis pain, an analysis of 20 studies found no evidence that the popular supplement prevents or reduces joint pain.

"We do not have evidence to suggest that chondroitin has a clinically relevant effect on patients' pain," says author Peter Juni, head of clinical epidemiology and biostatistics at the University of Bern in Switzerland.

Chondroitin is believed to help draw fluid into the cartilage, making it more flexible.

The paper comes a little more than a year after a major 16-site, $14 million National Institutes of Health study found no clear proof that the popular supplement combo glucosamine and chondroitin reduces joint pain.

The U.S. consumer market for glucosamine and chondroitin pills, almost always sold in combination, was $810 million in 2005, says Katja Rauhala, research manager with the Nutrition Business Journal.

The study was published in the Annals of Internal Medicine. The researchers analyzed chondroitin studies dating to 1970. The 20 clinical trials they studied included 3,846 patients. But early studies tended to involve small numbers of patients and were poorly designed, without proper documentation and analysis, Juni says.

For that reason, the researchers excluded all but three studies from their analysis. Those three were large, recent and well designed and together cover 40 percent of all the patients in the 20 trials.

After examining those studies, the Swiss researchers concluded that there is no evidence that chondroitin is unsafe, but also none to suggest that it helps diminish joint pain.

As to why so many patients swear by chondroitin as a treatment, Juni suggests that osteoarthritis — the degenerative joint disease seen especially in older people — is a condition that does not progress invariably toward more severe symptoms.

"You tend to have severe symptoms, and then you get better again," he says. "And if you happen to start chondroitin at the moment of severe disease and then it gets better, you might be convinced that it's the drug, but it's actually the body (healing)."

In an accompanying editorial in the journal, David Felson, an osteoarthritis expert at Boston University, says that despite the findings, some patients are convinced that chondroitin helps, and he believes there's no "harm in encouraging them to continue taking it as long as they perceive a benefit."

Frequent knee pain affects about 25 percent of adults, half of whom are estimated to have arthritis, Felson says.

One thing the study did not rule out is the possibility that chondroitin may lessen pain in patients with less severe arthritis. The most credible studies tended to include patients with more severe arthritis, Juni says.

Andrew Shao, vice president of scientific and regulatory affairs with the Council for Responsible Nutrition, a supplement industry group, says he doesn't think the analysis was fair in the criteria it used to exclude numerous studies that found chondroitin beneficial.

"Consumers speak with their wallets," Shao says. "This is not some kind of fad. Consumers are finding benefit from the drug."