Endothelial cell dysfunction, affecting the cells that line the blood vessels and control the ability of the vessels to expand and contract, is associated with an increased risk for coronary artery disease and cardiovascular events.  Some recently published studies suggest that soy isoflavones may reduce cardiovascular disease risk factors, most notably endothelial dysfunction and blood pressure.  D.P. Beavers, from Wake Forest University School of Medicine (North Carolina, USA), and colleagues completed a meta-analysis of 17 studies on the effect of isoflavones on endothelial function.   The team found that the overall change in flow-mediated dilation, a marker of endothelial function, for isoflavone-containing soy product interventions, to be 1.15%.  They urge that this significant improvement in flow-mediated dilation is clinically relevant, positing that the mechanism of effect involves the promotion of nitric oxide production, which is otherwise impaired in endothelial dysfunction and causes blood vessels to constrict.  The researchers conclude that: “Cumulative evidence … indicates that exposure to soy isoflavones can modestly, but significantly, improve [endothelial function].  Therefore, exposure to isoflavone supplements may beneficially influence vascular health.”