It has been almost a decade since I last reviewed chondroitin sulfate research.1 At that time, I reviewed five studies, all of which had impressive results.
Last year, a large meta-analysis of chondroitin supplementation for arthritis of the hip and knee was released.2 For those practitioners who favor the use of chondroitin sulfate, it was not encouraging.Conversely, providers who are skeptical felt validated. After a very thorough read, here are the facts as I see them.
- Researchers identified 1,453 references, spanning 36 years, in a literature search on chondroitin sulfate.
- Two hundred ninety-one of the studies and trials were potentially eligible.
- Twenty-two studies qualified, which included 4,056 patients.
- The mean number of subjects per study was 120.
- The number of subjects per study ranged from 17 to 631.
- The median age of subjects was 61 years.
- The age range of subjects (average) was 50 to 67 years.
- Seven trials reported the duration of symptoms, the range of which was four to 10 years.
- Doses ranged from 800 mg to 2,000 mg, with a median of 1,000 mg.
- Study times ran from six to 103 weeks, with a median of 25 weeks.
- Study follow-up times were from 13 to 132 weeks, with a median of 31 weeks.
Breakdown of Studies Included in the Review
- All 22 studies allowed pain medication.
- Twenty-one of the studies were randomized.
- Two studies used injectable chondroitin sulfate.
- Twenty studies used oral chondroitin sulfate.
- Nineteen studies used placebo control.
- Eighteen of 20 studies favored chondroitin sulfate over control.
- Seventeen of 20 studies had placebo controls.
- Twelve of 20 studies had adequate patient blinding.
- Eleven of 20 studies had a follow-up of greater than six months.
- Nine of 20 studies had a follow-up of less than six months.
- Nine of 18 studies that favored chondroitin sulfate had results that were not statistically significant.
- Five of 20 studies measured and reported radiological joint-space changes (see below).
- Two of 20 studies showed no difference between the chondroitin sulfate group and control group.
- Two of 20 studies had results showing no differences between chondroitin sulfate and control groups.
- Only one of 20 studies had clear nonprofit funding.
- None of 20 studies showed increased pain in the chondroitin group.
- Two-thirds of the best studies (according to the authors) had no effect.
In the five studies that measured joint spaces, the chondroitin groups lost a mean of 0.23 mm less joint space than the control group. The minimum difference was 0.16 mm less than the controls. The authors commented that there may be bias due to the small sample sizes of the five studies that measured joint-space changes with X-rays. In other words, they insinuated that the chondroitin sulfate advantage over controls in slowing of the joint space would not be seen in larger studies.
The Authors' Conclusions
- "No robust evidence supports the use of chondroitin in osteoarthritis."
- "Symptomatic benefit is minimal to nonexistent."
- "We deem it unlikely that patients with advanced osteoarthritis will benefit."
- "We cannot exclude a clinically relevant affect of chondroitin in patients with low-grade osteoarthritis."
- "In patients with low-grade osteoarthritis, the use of chondroitin should be restricted to randomized control trials."
- "In patients with advanced osteoarthritis, a clinically relevant benefit is unlikely, and the use of chondroitin should be discouraged."
In this meta-analysis, the use of chondroitin to control osteoarthritis of the knee and hip was not impressive. However, 18 of 20 oral studies that met vigorous inclusion criteria did favor chondroitin slightly. Although the authors felt that nine of 18 studies reached statistical significance, only two of 20 studies reached statistical significance for no effect and none favored placebo.
In my personal experience of more than 20 years in practice, it appears many patients subjectively benefit from the use of chondroitin sulfate (most of the time accompanied by glucosamine sulfate). Whether this simply is placebo or appropriate biochemistry has yet to be determined. After a close look at this study, I respectfully disagree with the authors and make the following conclusion: Chondroitin sulfate may not help everyone, but it is certainly worth a trial and is definitely safe.
- Andersen GD. "Chondroitin Sulfate Research Update." Dynamic Chiropractic, 1999;17(9):37. www.chiroweb.com/archives/17/09/04.html.
- Reichenbach S, Sterchi R, Scherer M, et al. Meta-analysis: chondroitin for osteoarthritis of the knee or hip. Ann Intern Med, 2007;146(8):580-90.
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