The effects of acute curcumin supplementation on markers of inflammation and oxidative stress after strenuous exercise

To determine the effects of curcumin supplementation on inflammatory and oxidative stress biomarkers following strenuous exercise. In a double-blinded, randomised, between-subjects design, 26 healthy males and females (mean ± SD: age: 25 ± 6 years, height: 171 ± 8 cm, weight: 69 ± 11 kg) consumed either 1000 mg/day of curcumin or a placebo for 4 days before completing 100 drop jumps and 50 squat jumps. Blood and urine samples were collected at pre-, post-, 1-, and 2-hour post-exercise to assess inflammatory (total and differential leukocyte concentrations, platelets, interleukin (IL)-6, IL-10, tumour necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), monocyte chemoattractant protein-1 (MCP-1), granulocyte colony-stimulating factor (G-CSF), vascular cell adhesion molecule-1 (VCAM-1)), and oxidative stress (glutathione peroxidase (GPX), 8-hydroxydeoxyguanosine (8-OHdG)) biomarkers. Curcumin metabolites (curcumin glucuronide, curcumin sufhate, bidemethoxycurcumin, and demethoxycurcumin) were measured pre-exercise to 1-hour post-exercise. Curcumin supplementation increased total plasma metabolites at all time-points (P < 0.05); the greatest mean increases were in curcumin glucuronide, which peaked 1-hour post-exercise (curcumin 211.7 ± 461.9 vs. placebo 1.1 ± 0.4 nM). Total leukocyte counts were lower in the curcumin condition at all time-points (supplement effect p < 0.05). Neutrophils were lower after curcumin 2-hours post-exercise (curcumin; 4.1 ± 1.5 vs. placebo: 5.8 ± 2.1 109 cells/L; p < 0.001). Plasma VCAM-1, G-CSF and urinary 8-OHdG were higher in the curcumin condition at all time-points (supplement effect; p < 0.05). There were no between group differences for any other biomarkers (p > 0.05). Curcumin supplementation increased circulating metabolites but had limited effects on markers of inflammation and oxidative stress after strenuous exercise, showing no clear pattern of change to suggest anti-inflammatory or antioxidant effects. https://osf.io/3k6yp/.