High-nitrate vegetable diet increases plasma nitrate and nitrite concentrations and reduces blood pressure in healthy women

<jats:title>Abstract</jats:title><jats:sec id="S1368980015000038_abs1" sec-type="general"><jats:title>Objective</jats:title><jats:p>Epidemiological studies suggest that green leafy vegetables, which are high in dietary nitrate, are protective against CVD such as stroke. High blood pressure (BP) is a major risk factor for stroke and inorganic nitrate has been shown to reduce BP. The objective of the present study was to test the hypothesis that diets containing high-nitrate (HN) vegetables would increase plasma nitrate and nitrite concentrations and reduce BP in healthy women.</jats:p></jats:sec><jats:sec id="S1368980015000038_abs2" sec-type="general"><jats:title>Design</jats:title><jats:p>A randomized, crossover trial, where participants received HN vegetables (HN diet) or avoided HN vegetables (Control diet) for 1 week. Before and after each intervention, resting BP and plasma nitrate and nitrite concentrations were measured.</jats:p></jats:sec><jats:sec id="S1368980015000038_abs3" sec-type="general"><jats:title>Setting</jats:title><jats:p>University of Exeter, UK.</jats:p></jats:sec><jats:sec id="S1368980015000038_abs4" sec-type="subjects"><jats:title>Subjects</jats:title><jats:p>Nineteen healthy women (mean age 20 (<jats:sc>sd</jats:sc>2) years; mean BMI 22·5 (<jats:sc>sd</jats:sc>3·8) kg/m<jats:sup>2</jats:sup>).</jats:p></jats:sec><jats:sec id="S1368980015000038_abs5" sec-type="results"><jats:title>Results</jats:title><jats:p>The HN diet significantly increased plasma nitrate concentration (before HN diet: mean 24·4 (<jats:sc>sd</jats:sc>5·6) µmol/l; after HN diet: mean 61·0 (<jats:sc>sd</jats:sc>44·1) µmol/l,<jats:italic>P</jats:italic>&lt;0·05) and plasma nitrite concentration (before HN diet: mean 98 (<jats:sc>sd</jats:sc>91) nmol/l; after HN diet: mean 185 (<jats:sc>sd</jats:sc>34) nmol/l,<jats:italic>P</jats:italic>&lt;0·05). No significant change in plasma nitrate or nitrite concentration was observed after the Control diet. The HN diet significantly reduced resting systolic BP (before HN diet: mean 107 (<jats:sc>sd</jats:sc>9) mmHg; after HN diet: mean 103 (<jats:sc>sd</jats:sc>6) mmHg,<jats:italic>P</jats:italic>&lt;0·05). No significant change in systolic BP was observed after the Control diet (before Control diet: mean 106 (<jats:sc>sd</jats:sc>8) mmHg; after Control diet: mean 106 (<jats:sc>sd</jats:sc>8) mmHg).</jats:p></jats:sec><jats:sec id="S1368980015000038_abs6" sec-type="conclusions"><jats:title>Conclusions</jats:title><jats:p>Consumption of HN vegetables significantly increased plasma nitrate and nitrite concentrations and reduced BP in normotensive women.</jats:p></jats:sec>