The effect of beetroot inorganic nitrate supplementation on cardiovascular risk factors: A systematic review and meta-regression of randomized controlled trials.

Abstract Objectives Inorganic nitrate is one of the most effective compounds in beetroot for improving cardiovascular function due to its conversion to nitric oxide in the body. This review and meta-analysis aimed to investigate the role of beetroot inorganic nitrate supplementation on adults' cardiovascular risk factors. Methods We conducted a systematic literature review of articles published without time limitation until November 2020 in PubMed, Embase, ISI Web of Science, Scopus, Cochrane Library, and gray literature databases. We included the original randomized clinical trials (RCTs) in which the effect of beetroot inorganic nitrate supplementation on endothelial function, arterial stiffness, and blood pressure was studied. Results 43 studies were included for qualitative synthesis, out of which 27 were eligible for meta-analysis. Beetroot inorganic nitrate supplementation significantly decreased Arterial Stiffness (Pulse Wave Velocity (−0.27 m/s, p = 0.04)) and increased Endothelial function (Flow Mediated Dilation: 0.62%, p = 0.002) but did not change other parameters (p > 0.05). Conclusion Beetroot inorganic nitrate supplementation might have a beneficial effect on cardiovascular risk factors. Further high-quality investigations will be needed to provide sufficient evidence.