The effects of dietary nitrate on blood pressure and vascular Health: An umbrella review and updated Meta-Analysis and meta-regression

[Display omitted] •We conducted a thorough evaluation of the impact of dietary nitrate on blood pressure and vascular health biomarkers in this umbrella review.•Dietary nitrate, as a complementary approach, can be used in the management of blood pressure and improving vascular health.•Benefits of dietary nitrate, may increase with higher doses and longer duration of supplementation, suggesting a potential dose–response relationship.•Future studies should also investigate the potential benefits of dietary nitrate supplementation on lipid and glycemic control, as well as potential cancer-related concerns. We aimed to comprehensively assess the impact of dietary nitrate supplementation on blood pressure (BP) and vascular health. We systematically searched PubMed, Scopus, and Web of Science until January 2024 to find eligible meta-analyses. For each meta-analysis, the mean difference and its 95% CI were recalculated using a random-effects model. We analyzed 113 studies involving 2013 participants and found that dietary nitrate supplementation can reduce both resting systolic and diastolic BP. Additionally, dietary nitrate can decrease pulse wave velocity and augmentation index while increasing flow-mediated dilation. Also, according to influence analysis results, dietary nitrate supplementation can reduce ambulatory systolic BP, ambulatory diastolic BP, and mean arterial pressure. The BP-lowering effect became more pronounced with increased study duration and nitrate dosage. Dietary nitrate supplementation may reduce BP and enhance vascular health. However, further research is needed on the dose–response relationship, long-term safety, and compliance with dietary nitrate.