Chondroitin sulfate improves osteoarthritis (OA) knee pain and functional limitations in walking and daily activities as effectively as the anti-inflammatory drug celecoxib (Celebrex), according to a new study published recently in Annals of the Rheumatic Diseases. But U.S. readers should know, there’s a catch: the researchers tested a version of chondroitin sulfate that is not available in this country.
Chondroitin is a naturally occurring component of cartilage, which helps cushion joints. The product is manufactured from animal sources and sold as an over-the-counter, oral dietary supplement in the United States. The highly purified, high-potency pharmaceutical-grade chondroitin sulfate used in the study is available European and other countries, and sold under the brand names Chondrosulf, Condrosulf and Condral. Celecoxib is a nonsteroidal anti-inflammatory drug (NSAID) that in studies has been found to help relieve OA pain and is often used in OA drug trials for comparison. This study, conducted in four European countries, was funded by IBSA, the pharmaceutical company that markets Chondrosulf.
During the randomized, double-blind study, 604 patients diagnosed with symptomatic knee OA received one of three drug treatments: 800 milligrams a day of chondroitin, 200 milligrams of celecoxib or a placebo (dummy) pill. At the end of six months, all participants reported improved pain and mobility (underscoring the fact that the placebo effect is common in OA treatment, as seen in other studies), but the patients who took chondroitin or celecoxib had significantly more improvement than the patients who took placebo. No difference in effectiveness was seen between the chondroitin and celecoxib groups except (for some measures) in timing: the group taking celecoxib reported symptom improvement after 30 days, whereas the chondroitin group reported benefit at 90 days.
Celecoxib and other NSAIDs can cause serious side effects, including stomach bleeding and ulcers, kidney and liver problems, and heart attack and stroke. Chondroitin, which is considered safe, isn’t associated with any of these problems. Because this study showed safety and effectiveness, the study authors recommend it as a first-line treatment for knee OA.
But not all experts may agree. Chondroitin has a somewhat checkered past. It has been studied in dozens of trials, often with mixed results. One of the best known studies done in the United States, the GAIT trial, tested chondroitin alone or combined with the dietary supplement glucosamine, and compared them with celecoxib and placebo. In that trial, only a small subset of patients (those with moderate-to-severe pain from knee OA) experienced significantly more pain improvement with chondroitin plus glucosamine than patients in the placebo group. The study authors noted the subgroup was too small to draw conclusions from, and called for further studies.
Many experts say the mixed results in past studies may be due to the variation in quality of chondroitin used in studies. The many brands available to consumers in the U.S., either alone or in combination formulas with glucosamine or other substances, vary widely in purity and potency. Pharmaceutical-grade chondroitin in Europe, typically available with a prescription, is standardized and verified for purity and potency.
Marc Hochberg, MD, the head of rheumatology at the University of Maryland Medical Center in Baltimore, has studied European chondroitin and glucosamine for OA with positive results. In a 2015 clinical trial, also published in Annals of the Rheumatic Diseases, he and his colleagues reported that a combination of chondroitin and glucosamine reduced knee OA pain by around 50 percent – the same as celecoxib.
“Pharmaceutical-grade chondroitin sulfate, manufactured by IBSA, is approved in Europe for the treatment of OA and has been shown to be effective for both hand and knee pain,” says Dr. Hochberg, referring to the Chondrosulf maker. “The company has not conducted studies in the U.S. nor submitted a dossier to the [Food and Drug Administration] for approval, which is why it isn’t available [here].”
Lead study author Jean-Yves Reginster, MD, a professor of epidemiology at Liège State University in Belgium, adds that the results of his trial “cannot be extrapolated to over-the-counter or generic products.”
For people who don’t have access to prescription chondroitin, Adam Perlman, MD, former executive director of Duke Integrative Medicine in Durham, North Caroline, suggests trying the highest quality chondroitin you can find in the U.S.
“I always recommend trying the product used in a clinical trial,” he says. “Or check with ConsumerLab [consumerlab.org, an independent testing company that rates supplements] or some other testing agency to make sure you’re at least getting the amount of chondroitin listed on the label.”
One product he finds effective for his patients is the Dona brand, which is widely available and relatively inexpensive. He also says that some people who have initial success with chondroitin, glucosamine or both may find them less helpful over time. In that case, he suggests taking a break for a month or two before trying them again.
Author: Linda Rath for the Arthritis Foundation
- 25 Treatments for Arthritis Hip & Knee Pain
- Running with Knee Osteoarthritis
- New Pain Treatment for Knee Osteoarthritis Targets Nerves