Observational studies have shown that a higher intake of nitrate from dietary vegetables is associated with a lower risk of cardiovascular disease and of cardiovascular disease mortality.[1][2] Accordingly, some randomized controlled trials have shown that supplementation with nitrate can improve variables associated with cardiovascular health. For example, supplementation with nitrate (sodium nitrate/potassium nitrate capsules, beetroot juice, or beetroot extract) has been shown to lower blood pressure[3][4][5] and increase flow-mediated dilation in large blood vessels (a.k.a. vascular function).[6][3] However, the effect of nitrate on blood pressure in people with hypertension is variable and needs further research.[7][5][3][8][9][10] Furthermore, it has yet to be determined whether nitrate-induced improvements in blood pressure or vascular function contribute to a lowered risk of cardiovascular disease.
Supplementation with nitrate or beetroot juice before exercise shows only trivial effects when pooling all types of aerobic exercise performance tests but small to moderate beneficial effects on time to exhaustion at a fixed intensity.[11][12][13][14][15] Some studies have also found a benefit of nitrate/beetroot juice on sprint performance metrics and power/velocity during resistance-based exercises, suggesting that supplementation with nitrate might improve explosive exercise performance.[16][17][18] However, not all studies confirm such findings, and the effects vary between studies.[16][17][18] Supplementation with nitrate/beetroot juice might also reduce the oxygen cost of exercise and, therefore, improve running/cycling economy.[12]
Although nitrate is converted to nitrite by bacteria in the mouth to allow humans to synthesize nitric oxide from nitrate (see How does nitrate work?),[19][20] consuming nitrate also provides oral bacteria with a source of nitrite, which may play a role in maintaining oral health.[21][22][23]