Dietary supplements for treating osteoarthritis: a systematic review and meta-analysis

Liu X, Machado GC, Eyles JP, Ravi V, Hunter DJ · British Journal of Sports Medicine

Puts collagen in context against every competitor. Collagen hydrolysate was one of seven supplements with large (effect size >0.80) and clinically important short-term pain effects; undenatured type II collagen showed statistically significant but unclearly important effects short-term, and was one of only two supplements (with green-lipped mussel) retaining a clinically important effect at medium term. The decisive finding: NO supplement had clinically important effects on pain or function at long-term follow-up, and glucosamine and chondroitin were 'either ineffective or showed small and arguably clinically unimportant treatment effects'.

Population

69 studies covering 20 dietary supplements in hand, hip or knee osteoarthritis

Intervention

Dietary supplements including collagen hydrolysate and undenatured type II collagen

Comparator

Placebo

Limitations

GRADE quality ranged from very low to high and the authors describe the overall short-term finding as resting on very low quality evidence. Competing interests: none declared — independent.