A meta-analysis of 66 RCTs shows that curcumin supplementation significantly but modestly reduces inflammatory markers (CRP, TNF-alpha, IL-6). The practical benefit is strongly limited by the poor absorption of curcumin in the body, and proven effectiveness for specific inflammatory diseases in humans is currently lacking.
Curcumin, the active compound in turmeric (also known as 'geelwortel' in Dutch, or 'turmeric' in English), has been shown in a large meta-analysis of 66 randomised controlled trials to significantly reduce various inflammatory markers in the blood. CRP dropped by an average of 0.58 mg/l, TNF-alpha dropped by 3.48 pg/ml, and IL-6 dropped by 1.31 pg/ml. For IL-1beta, another inflammatory substance, no significant effect was found. The effects are statistically reliable but modest in size (PMID 36804260).
In addition to inflammatory markers, curcumin also improved antioxidant status in the same meta-analysis: oxidative damage (measured via MDA) decreased, while total antioxidant capacity (TAC) and the protective enzyme SOD increased. This is consistent with mechanistic evidence, in which curcumin has been shown in laboratory and animal research to inhibit pro-inflammatory enzymes such as COX-2 (the same target as ibuprofen), LOX, and iNOS (PMID 17569207, 18662800). Whether this inhibition works as strongly in humans as it does in the laboratory has not yet been directly demonstrated.
For specific conditions such as inflammatory bowel disease, psoriasis, and atherosclerosis, review studies describe curcumin as 'promising', but proven effectiveness as a treatment is currently lacking. The researchers emphasise that curcumin is a candidate, not a proven therapy (PMID 34754179).
A crucial practical problem is its low bioavailability: the body naturally absorbs curcumin poorly, and it is rapidly broken down and excreted. Ordinary turmeric powder or standard capsules therefore deliver only a fraction of the active substance to the bloodstream. Improved formulations, such as nanocurcumin or combination with piperine (a compound from black pepper), are being investigated to address this, but have not yet been proven in standard practice (PMID 34754179, 34012421).
In animal models (worms, fruit flies, yeast, and mice), lifespan extension by curcumin has also been described, via antioxidant activity and the influencing of ageing signalling pathways such as mTOR and FOXO. Whether this is relevant in humans is entirely unknown and has not been investigated in the available studies (PMID 33360051).
All claims are based on one large meta-analysis of 66 RCTs (PMID 36804260), supplemented by mechanistic reviews and animal models. There is no evidence of effectiveness as a treatment for specific diseases in humans. The bioavailability problem has been consistently reported across multiple sources.