Chondroitin for osteoarthritis

Singh JA, Noorbaloochi S, MacDonald R, Maxwell LJ · Cochrane Database of Systematic Reviews

On the highest-quality node — WOMAC minimal clinically important improvement, level of evidence HIGH, risk of bias LOW — 53 of 100 on chondroitin achieved a 20% pain reduction against 47 of 100 on placebo, an absolute risk difference of 6% (95% CI 1% to 11%; RR 1.12, 95% CI 1.01 to 1.24; I-squared 0%), on 2 trials and 1,253 participants. Loss of minimum joint space width was a relative 4.7% less than placebo (95% CI 1.6% to 7.8% less; 2 trials), also HIGH quality and LOW risk of bias. Short-term pain gave a 10% absolute risk difference (95% CI 15% to 6% lower; NNT 5) but on 8 trials with I-squared of 70%, low-quality evidence and high risk of bias. Serious adverse events were lower than placebo, Peto odds ratio 0.40 (95% CI 0.19 to 0.82; 6 trials).

Population

43 randomized trials, 4962 participants on chondroitin and 4148 on placebo or another control, mostly knee osteoarthritis

Intervention

Oral chondroitin, alone or combined

Comparator

Placebo, NSAIDs, analgesics or glucosamine

Limitations

The authors' own summary opens 'a review of randomized trials of mostly low quality', and their central caveat is that the benefits in pain and Lequesne's index 'were uncertain when we limited data to studies with appropriate allocation concealment or a large study sample (> 200) or to studies without pharmaceutical funding'. High heterogeneity throughout. All trials used pharmaceutical-grade chondroitin at 800-1200 mg/day — nothing here transfers to chondroitin delivered in food.