Nitric oxide (NO) plays a significant role in vascular health, including the function of veins. Scientifically, NO is recognized as a critical endothelium-derived relaxing factor that helps regulate vascular tone by inducing smooth muscle relaxation, which leads to vasodilation. This mechanism has been well-documented in research since the 1980s. Although most research focuses on arteries, the vasodilatory effect also benefits the venous system by improving blood flow and reducing venous tone, which can be beneficial in conditions like chronic venous insufficiency and varicose veins.

Clinical studies have demonstrated that increasing NO bioavailability, either through dietary nitrates (such as beetroot juice) or pharmacological agents (like nitroglycerin), can improve endothelial function and venous return. For example, nitroglycerin, which is metabolized to NO, is used to treat angina and heart failure by reducing preload and afterload, affecting both arteries and veins.

While the majority of studies focus on arterial health, the venous benefits are a logical extension of NO’s systemic vascular effects. There is robust scientific evidence supporting the vasodilatory and protective effects of NO on the vascular system, including veins, although more direct research focusing solely on the venous system is somewhat limited compared to arterial studies.