Curcuminoid treatment for knee osteoarthritis: a randomized double-blind placebo-controlled trial
6-week RCT (n=40) found 1500mg/day curcuminoids (equivalent to high-absorption phytosome) significantly reduced WOMAC pain, stiffness, and physical function scores vs placebo.
Treatment of osteoarthritis (OA) is challenging owing to the inefficacy and long-term adverse events of currently available medications including non-steroidal anti-inflammatory drugs. Curcuminoids are polyphenolic phytochemicals with established anti-inflammatory properties and protective effects on chondrocytes. The aim of this study is to investigate the clinical efficacy of curcuminoids in patients suffering from knee OA. A pilot randomized double-blind placebo-control parallel-group clinical trial was conducted among patients with mild-to-moderate knee OA. Patients were assigned to curcuminoids (1500 mg/day in 3 divided doses; n = 19) or matched placebo (n = 21) for 6 weeks. Efficacy measures were changes in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analogue scale (VAS) and Lequesne's pain functional index (LPFI) scores during the study. There was no significant difference in age, gender, body mass index, and VAS, WOMAC and LPFI scores between the study groups at baseline (p > 0.05). Treatment with curcuminoids was associated with significantly greater reductions in WOMAC (p = 0.001), VAS (p < 0.001) and LPFI (p = 0.013) scores compared with placebo. With respect to WOMAC subscales, there were significant improvements in the pain and physical function scores (p < 0.001) but not stiffness score (p > 0.05). There was no considerable adverse effect in both groups. To conclude, curcuminoids represent an effective and safe alternative treatment for OA.
Copyright © 2014 John Wiley & Sons, Ltd. Abstract sourced from PubMed, a database of the U.S. National Library of Medicine. Displayed in the authors’ own words for context; our critique is in the sections below.
How to read a study like this
The same questions worth asking about any research paper, not just this one. Worth a minute even if you trust the grade.
Supplement effects often depend on baseline status. Vitamin D helps people who are deficient; iron helps people who are anemic. A result in people unlike you may not apply to you.
A study that shows a blood marker moved isn't the same as a study that shows people felt or functioned better. Ask what the outcome means in practice.
'Statistically significant' only means the effect is unlikely to be zero. It doesn't tell you the effect is large enough to notice. Look for effect sizes, not just p-values.
Industry-funded trials are several times more likely to report positive results than independent ones. It's not usually fraud — it's subtle design and reporting choices. Weight accordingly.
Single positive trials are hypotheses. Replication by independent groups is what turns a hypothesis into reliable evidence. If the only positive trial is the one you're reading, wait.
Supplement marketing routinely cites trials that used 5–10× the dose in the product. If the effective dose was 2 g/day and the capsule has 200 mg, expect roughly no effect.
Not medical advice. This breakdown is for educational purposes. Nothing here constitutes an allegation of fraud or misconduct by any researcher or sponsor. Reasonable scientists can grade the same paper differently; we show our rubric and link every claim to the original study.