Dietary flavanols maintain endothelial homeostasis

Abstract

Dietary intervention studies showed that flavanols can improve endothelial function. We investigated how dietary flavanols affect the balance of endothelial homeostatic regeneration and repair processes. We show in a randomized controlled clinical study that 1 month ingestion of a high flavanol drink (750 mg total flavanols) increased endothelial function (flow‐mediated vasodilation [FMD]) and decreased systolic blood pressure in patients with coronary artery disease. This increase correlated with an increase in the number of circulating angiogenic cells (CACs; CD34+/KDR+ and CD133+/KDR+). Furthermore, flavanols led to a decrease in the numbers of endothelial microparticles (CD31+/CD41‐; CD144+), markers of endothelial injury, as measured by flow cytometry. This was inversely correlated with FMD. Platelet microparticles (CD41+) remained unaffected. In vitro, low nanomolar concentrations of (−)‐epicatechin and flavanol‐rich plasma increased the migratory capacity of CACs and endothelial cells, closure of an endothelial scratch injury, and capillary network formation. Flavanol metabolites increased eNOS activity and led to vasodilation of aortic rings. In mice, epicatechin feeding over one week improved vascular function, angiogenesis (hindlimb ischemia), and aortic GSH levels. Our data lend evidence to the concept that dietary flavanols may help maintain endothelial homeostasis.