Depleted nitric oxide levels in the human body play a major role in cardiovascular disease pathogenesis. Inorganic nitrate/nitrite (rich dietary sources include beetroot and spinach) can act as a nitric oxide donor because nitrate/nitrite can be metabolized to produce nitric oxide.Objective
This review and meta-analysis sought to investigate the role of inorganic nitrate/nitrite in preventing or treating cardiovascular disease risk factors in humans.Data Sources
Electronic databases, including Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane, and Scopus, were searched.Data Extraction
Experimental trials examining the effect of oral inorganic nitrate/nitrite intake on cardiovascular disease risk factors were included for systematic analysis.Results
Thirty-four studies were included for qualitative synthesis, 23 of which were eligible for meta-analysis. Included studies measured the following outcomes: blood pressure, endothelial function, arterial stiffness, platelet aggregation, and/or blood lipids. Inorganic nitrate intake was found to significantly reduce resting blood pressure (systolic blood pressure: −4.80 mmHg, P < 0.0001; diastolic blood pressure: −1.74 mmHg, P = 0.001), improve endothelial function (flow-mediated dilatation: 0.59%, P < 0.0001), reduce arterial stiffness (pulse wave velocity: −0.23 m/s, P < 0.0001; augmentation index: −2.1%, P = 0.05), and reduce platelet aggregation by 18.9% (P < 0.0001).Conclusions
Inorganic nitrate consumption represents a simple strategy for targeting cardiovascular disease risk factors. Future studies investigating the long-term effects of inorganic nitrate on cardiovascular disease outcomes are warranted.