When a patient asks whether it makes sense to use chondroitin for osteoarthritis, the following are appropriate responses:
- It may moderately reduce the pain in your knee.
- Consider the cost.
- Try a variety of therapies before you settle on one.
- Over-the-counter analgesics can also be effective, as can physical therapy, weight loss, and exercise.
A recent meta-analysis published in January by the Cochrane Collaboration found that chondroitin (chondroitin polysulfate) may slightly reduce pain, particularly knee pain, for up to six months in patients with osteoarthritis.
It Might Just Work
Participants who received chondroitin rated their pain 10 points lower on a 0 to 100 pain scale than controls who took a placebo. Among patients in the active groups, 53% said that chondroitin reduced their knee pain compared to 47% of those in control groups. Chondroitin also appeared to slightly slow the narrowing of space in arthritic joints and to improve quality of life. It was not associated with any serious adverse events.
“Based on the data analyzed in the article, there is a signal of clinically meaningful decrease in pain and functional status of patients with osteoarthritis. Additionally, there was no safety signal to preclude its use,” Apostolos Kontzia, MD, told MDalert.com. Dr. Kontzia is associate staff in the Department of a Rheumatology and Immunologic Disease at Cleveland Clinic, in Cleveland Ohio.
“However, it must be stressed that most of the cited existing studies assessing efficacy of chondroitin use small numbers of patients and additionally the ones that use larger samples fail to replicate the signal,” he added.
The reviewers analyzed 43 studies that included 9,110 participants. The reviewers also searched the U.S. Food and Drug Administration and European Medicines Agency websites for adverse effects. Studies lasted at least two weeks. Participants took either chondroitin alone or with glucosamine, a placebo, or an active control such as a NSAID.
Included in the review were “a lot of studies in which unsound methods were used to assess the effects of chondroitin. For some outcomes, there was not enough data. In some studies, whose methodological quality was better, chondroitin showed no improvement in pain and in physical function,” noted the Cochrane authors. Many studies had fewer than 100 participants.
Cost May Be Worst Adverse Event
On the up side, “chondroitin had a lower risk of serious adverse events compared with control,” according to the reviewers.
“It is very clear from the article that chondroitin use is overall safe to use even at doses reaching 800mg daily at least short term, even though patient follow up was not long enough for many of the studies. Based on the evidence that this article presents, a trial of chondroitin for six months at a dose of 800-1000 mg daily is an acceptable recommendation,” said Dr. Kontzia.
Beyond 6 months of treatment, the review could not ascertain whether chondroitin continued to benefit patients.
Non-Pharma Data Are Weak
When the Cochrane researchers limited their evaluation to those studies without pharmaceutical funding, they were unable to confirm the benefit of chondroitin, perhaps because industry-sponsored studies use higher quality products. Put another way, those studies may actually use chondroitin, while it is unclear that what’s sold as chondroitin by most retailers actually contains any chondroitin sulphate.
A study published in BMC Medicine in October found that just two of 12 major manufacturers of supplements sold in North America did not use undisclosed supplements or substitutions in their products. The New York Attorney General’s office found that 80% of tested supplements sold by leading retailers contained none of the listed ingredients.
Based on a Cochrane Collaboration meta-analysis and an interview with Apostolos Kontzia, MD.