Soybean and its derivatives, particularly soy protein and isoflavones, have been researched for their effects on cardiovascular health, including the function and health of arteries. Multiple human studies and meta-analyses suggest that regular consumption of soy protein can modestly lower LDL ("bad") cholesterol, which is a key risk factor for atherosclerosis and arterial disease. The U.S. Food and Drug Administration (FDA) once authorized a health claim for soy protein's cholesterol-lowering effects, although the strength of evidence has been debated and the claim was under review as of 2017.

Soy isoflavones, which are phytoestrogens found abundantly in soybeans, have also been investigated for their potential to improve arterial stiffness and endothelial function, both important for maintaining healthy arteries. Some studies have shown improvements, especially in postmenopausal women, but results are not entirely consistent.

Overall, the scientific evidence supports a modest benefit of soy consumption for arterial and cardiovascular health, primarily through cholesterol reduction and possible improvements in vascular function. The rating reflects that while there is clear evidence of benefit, the effect size is moderate, and not all studies are in agreement. There is not a strong tradition in herbal or folk medicine specifically linking soy to arterial or heart health; the support is based primarily on modern scientific research.