Flavan-3-ols and Vascular Health: Clinical Evidence and Mechanisms of Action

Abstract

Cardiovascular diseases (CVDs) are one of the main causes of mortality and morbidity worldwide. A healthy diet rich in plant-derived compounds such as (poly)phenols appears to have a key role in improving cardiovascular health. Flavan-3-ols represent a subclass of (poly)phenols of great interest for their possible health benefits. In this review, we summarized the results of clinical studies on vascular outcomes of flavan-3-ol supplementation and we focused on the role of the microbiota in CVD. Clinical trials included in this review showed that supplementation with flavan-3-ols mostly derived from cocoa products significantly reduces blood pressure and improves endothelial function. Studies on catechins from green tea demonstrated better results when involving healthy individuals. From a mechanistic point of view, emerging evidence suggests that microbial metabolites may play a role in the observed effects. Their function extends beyond the previous belief of ROS scavenging activity and encompasses a direct impact on gene expression and protein function. Although flavan-3-ols appear to have effects on cardiovascular health, further studies are needed to clarify and confirm these potential benefits and the rising evidence of the potential involvement of the microbiota.

Keywords: flavan-3-ols; gut microbiota; inflammation; polyphenols; vascular.

Figure 1

A schematic overview of the primary activities of microbial-derived metabolite flavan-3-ols. ACE (angiotensin-converting enzyme); CAT (catalase); eNOS (endothelial nitric oxide synthase); GSH (glutathione peroxidase); IL-1β (interleukin-1β); IL-6 (interleukin-6); iNOS (inducible nitric oxide synthase); NF-κB (nuclear factor-kappa B); NO (nitric oxide); ROS (reactive oxygen species); SOD (superoxide dismutase); TNF-α (tumor necrosis factor-alpha).