Dietary fiber blends, typically composed of soluble and insoluble fibers such as psyllium husk, inulin, oat bran, and others, have substantial scientific evidence supporting their role in arterial and cardiovascular health. Multiple large epidemiological studies and clinical trials have demonstrated that increased dietary fiber intake is associated with reduced risk of cardiovascular disease, including atherosclerosis and hypertension. Soluble fibers, in particular, can lower blood cholesterol levels by binding bile acids in the gut, leading to increased excretion and reduced circulating cholesterol, a major risk factor for arterial plaque formation.

The American Heart Association and other reputable organizations recommend fiber intake for cardiovascular support, citing findings from meta-analyses showing decreased incidence of coronary heart disease and stroke with higher fiber consumption. Fiber may also improve arterial health indirectly by improving glycemic control, reducing systemic inflammation, and promoting a healthy gut microbiota, which in turn may influence vascular function.

However, the specific efficacy of "proprietary fiber blends" depends on their exact composition and dosage, as not all fibers have identical effects. Still, the general category of dietary fiber is well-supported for arterial health, making its use justified by current scientific understanding.