Chondroitin sulphate was associated with a significant reduction in joint space loss, and pain in, compared to the placebo group, according to researchers, led by Andre Kahan of the University of Paris Descartes in Paris.
The results of the study were published in the February issue of Arthritis & Rheumatism.
The researchers stress, however, that since the specific chondroitin preparation used in their study has been approved as a prescription drug in many European companies, there results “cannot be generalized to other chondroitin sulphate products (or compound mixtures) such as those available in some countries as dietary supplements”.
Chondroitin sulphate is extracted from animal cartilage, such as sharks. In dietary supplements the compound is often formulated in combination with glucosamine. According to the Nutrition Business Journal, US sales for these combined supplements were $810 million (€563 million) in 2005.
Previous studies, including the $14m Glucosamine/chondroitin Arthritis Intervention Trial (GAIT), sponsored by the National Institute of Health, have reported positive results, while other have reported null results, leaving the subject clouded in uncertainty.
Recent results from GAIT II did not help to clarify the subject, with results showing that supplements of chondroitin sulphate and glucosamine, alone or in combination, may not positively affect joint health.
The participants were randomly assigned to receive with an 800 mg sachet of CS (Genevrier Laboratories, France, and IBSA, Switzerland) or a placebo sachet. Supplementation lasted for two years. The CS preparation contained high purity (at least 95 per cent) chondroitins 4 and 6 sulphate of bovine origin.
The randomised, double-blind, placebo-controlled study included 622 people with osteoarthritis. Their average age was 62, and approximately 70 per cent were women.
The results showed that: "Long-term administration of CS over 2 years can prevent joint structure degradation in patients with knee OA," wrote Kahan and co-workers.
Regarding pain, people in the chondroitin group experienced a faster improvement, said the researchers. This may be due to the fact that all of the patients had pain symptoms, they said, so the effect of CS was more noticeable early on. On the other hand, pain was found to decrease in the placebo group, too, over the course of the first year.
"Further studies with longer follow-up and different outcome criteria are warranted to assess whether the beneficial structural changes associated with chondroitin sulphate demonstrated in our study are predictive of improvement in the long-term clinical progression of osteoarthritis," concluded the researchers.
Approximately seven million people in the UK alone are reported to have long-term health problems associated with arthritis. Around 206 million working days were lost in the UK in 1999-2000, equal to £18 billion (€26 billion) of lost productivity.
Source: Arthritis & RheumatismFebruary 2009, Volume 60, Issue 2, Pages 524-533“Long-term effects of chondroitins 4 and 6 sulfate on knee osteoarthritis: The study on osteoarthritis progression prevention, a two-year, randomized, double-blind, placebo-controlled trial”Authors: A. Kahan, D. Uebelhart, F. De Vathaire, P.D. Delmas, J.-Y. Reginste