Substantial Variability Across Individuals in the Vascular and Nutrigenomic Response to an Acute Intake of Curcumin: A Randomized Controlled Trial

Scope: Curcumin exerts biological activities of interest in cardiovascular prevention. However, its vascular protective effect is still poorly investigated in humans. The present study aims to assess vascular effect of an acute intake of curcumin and its nutrigenomic impact in circulating immune cells.

Methods and results: In a randomized, double-blind, crossover design, 18 healthy smokers consume a placebo or a 5-g curcumin. Before and 2 h after the intake, vascular function measurements are performed by using flow-mediated dilation (FMD). In addition, endothelial function in the microcirculation and blood pressure are evaluated. Plasma curcumin concentrations and changes in gene expression in peripheral blood mononuclear cells (PBMC) are analyzed. No significant effect of curcumin on FMD is observed when considering the entire study population, mainly due to a high interindividual variability. A subgroup analysis according to the gender or the cardiovascular-risk score reveals a significant effect of curcumin on FMD in women and in subjects presenting lower cardiovascular risk. No change in gene expression is observed when data are analyzed for all volunteers but changes in expression are observed when analyzed according to gender.

Conclusions: This clinical trial highlights that a substantial variability in efficacy of curcumin exists across individuals.