{Reference Type}: Journal Article {Title}: Flavan-3-ols and Vascular Health: Clinical Evidence and Mechanisms of Action. {Author}: Godos J;Romano GL;Laudani S;Gozzo L;Guerrera I;Dominguez Azpíroz I;Martínez Diaz R;Quiles JL;Battino M;Drago F;Giampieri F;Galvano F;Grosso G; {Journal}: Nutrients {Volume}: 16 {Issue}: 15 {Year}: 2024 Jul 30 {Factor}: 6.706 {DOI}: 10.3390/nu16152471 {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.