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

Abstract

OBJECTIVE:

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.

DESIGN:

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.

SETTING:

University of Exeter, UK.

SUBJECTS:

Nineteen healthy women (mean age 20 (sd 2) years; mean BMI 22·5 (sd 3·8) kg/m2).

RESULTS:

The HN diet significantly increased plasma nitrate concentration (before HN diet: mean 24·4 (sd 5·6) µmol/l; after HN diet: mean 61·0 (sd 44·1) µmol/l, P<0·05) and plasma nitrite concentration (before HN diet: mean 98 (sd 91) nmol/l; after HN diet: mean 185 (sd 34) nmol/l, P<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 (sd 9) mmHg; after HN diet: mean 103 (sd 6) mmHg, P<0·05). No significant change in systolic BP was observed after the Control diet (before Control diet: mean 106 (sd 8) mmHg; after Control diet: mean 106 (sd 8) mmHg).

CONCLUSIONS:

Consumption of HN vegetables significantly increased plasma nitrate and nitrite concentrations and reduced BP in normotensive women.

• Authors: Ann Ashworth, Klaus Mitchell, Jamie R Blackwell, Anni Vanhatalo, Andrew M Jones
• Journal: Public health nutrition (Public Health Nutr) Vol. 18 Issue 14 Pg. 2669-78 (Oct 2015) ISSN: 1475-2727 [Electronic] England
• PMID: 25683748 (Publication Type: Journal Article, Randomized Controlled Trial)

Chemical References

• Nitrates
• Nitrites

Topics

• Adolescent
• Adult
• Blood Pressure (drug effects)
• Cross-Over Studies
• Diet
• Feeding Behavior
• Female
• Humans
• Hypertension (blood, diet therapy, prevention & control)
• Nitrates (blood, pharmacology, therapeutic use)
• Nitrites (blood)
• Reference Values
• Vegetables (chemistry)
• Young Adult