Abstract/Summary

Background: Dietary inorganic nitrate from vegetable sources has been shown to lower blood pressure (BP) and improves endothelial function. However, the impact of nitrate from different dietary sources on BP remains unclear. Objective: To determine the relationships between dietary nitrate and nitrite from vegetables (with drinking water) and processed meats with BP and other cardiovascular disease (CVD) risk markers in a representative UK population. Methods: Data from the cross-sectional National Diet and Nutrition Survey Years 1-8, adults, (19-64 years) was used. For the analysis, a database of nitrate and nitrite concentrations in vegetables, drinking water, processed meats and composite dishes was developed. The population was stratified into quartiles of increasing total and daily nitrate or nitrite intakes from vegetables (including drinking water) and processed meats to determine the relationships with biomarkers of CVD risk [(BP, lipid profile, C-reactive protein (CRP), anthropometric measures and glycemic control] using an analysis of covariance. Results: This dataset included 3338 adults (59% female) with a mean age of 43 years (SD 12). Across increasing quartiles of vegetable nitrate intake, systolic BP (SBP), diastolic BP, waist circumference, waist-to-hip ratio and glycated hemoglobin were lower in Q3 (95-130mg/d nitrate) than Q1 (3-65mg/d) (P≤0.038). Participants in Q4 (>131mg/d) had lower pulse pressure, glucose, CRP and total cholesterol concentrations compared to Q1 (P≤0.05). Similar beneficial associations on SBP and lipid profiles were also evident for dietary nitrite intake from vegetables (P≤0.05). In contrast, there were no difference in CVD risk biomarkers across quartiles of nitrate intake from processed meats, with higher SBP in Q4 (1.8-3 mg/d nitrate) vs Q1 (0.1- 0.8 mg/d) (P=0.010). Conclusion: These data suggest the dietary source of dietary nitrate and nitrite may play an important role in determining the relationship with BP and other CVD risk biomarkers in a representative UK population.