Nitrate, primarily found in leafy green vegetables and beetroot, is scientifically recognized for its role in supporting vascular health, including the capillaries. When ingested, dietary nitrate is converted in the body to nitrite and then to nitric oxide (NO), a molecule well known for its vasodilatory effects. Nitric oxide relaxes the smooth muscle in blood vessels, resulting in improved blood flow and reduced blood pressure. While most research focuses on the effects of nitrate on larger arteries and overall vascular function, some studies suggest that enhanced NO bioavailability can also support microcirculation, which includes the capillary network.

Clinical trials have demonstrated that dietary nitrate supplementation can improve endothelial function, which encompasses the health of both large and small blood vessels. For example, beetroot juice supplementation has been shown to increase microvascular blood flow in humans. However, while the evidence supporting nitrate’s role in supporting general vascular health is robust, direct evidence specifically targeting “capillary support” is still emerging and less comprehensive. Thus, nitrate is considered scientifically validated for general vascular health, with moderate evidence for direct capillary benefits.

In summary, nitrate is scientifically validated for supporting vascular function, with some promising but not yet definitive evidence for direct capillary support, justifying a moderate evidence rating.