Curcumin is the primary curcuminoid in turmeric. It has anti-inflammatory properties mediated through NF-kappaB inhibition, is a potent antioxidant, has anti-proliferative effects in cancer cell lines, crosses the blood-brain barrier, and modulates multiple signalling pathways implicated in chronic disease. The laboratory evidence is genuinely impressive. The clinical evidence in humans is more nuanced because curcumin is poorly absorbed from the gut in isolated form.
The Bioavailability Issue and How to Solve It
Isolated curcumin has very low bioavailability: most passes through the gut unabsorbed. However, two simple additions dramatically improve absorption. Piperine from black pepper increases curcumin bioavailability by 2,000 percent in the presence of fat. Traditional Indian cookery that combines turmeric with black pepper and fat-based cooking achieves this combination automatically. The epidemiological association between high turmeric consumption in South Asian populations and lower rates of certain cancers may partially reflect this synergistic combination.
What the Human Evidence Shows
- Inflammatory markers: a meta-analysis of 9 RCTs found that curcumin supplementation significantly reduced CRP, IL-6, and TNF-alpha, all markers of systemic inflammation
- Osteoarthritis pain: multiple RCTs find curcumin reduces knee pain and improves function comparably to ibuprofen, with better gastrointestinal tolerability
- Metabolic syndrome: RCTs show improvements in triglycerides, blood sugar, and waist circumference in adults with metabolic syndrome
- The practical advice: use 1 teaspoon of turmeric with a pinch of black pepper daily in cooking rather than relying on supplements; this provides the synergistic food matrix that supplements cannot replicate