title: Short-term effects of nitrate-rich green leafy vegetables on blood pressure and arterial stiffness in individuals with high-normal blood pressure.
abstract: Evidence for a beneficial effect of dietary nitrate, through the nitrate-nitrite-NO pathway, on measures of cardiovascular function in healthy individuals is accumulating. It is less clear whether increased dietary nitrate intake from green leafy vegetables would have similar beneficial vascular effects in those at increased risk of developing hypertension. Our aim was to assess the effects of short-term regular consumption of increased nitrate from green leafy vegetables on blood pressure and arterial stiffness in individuals with high-normal blood pressure. Thirty-eight men and women ages 30-70 years with systolic blood pressure 120 to 139 mm Hg were recruited to a randomized controlled crossover trial. The effects of a 7-day high-nitrate diet intervention (increased nitrate intake by at least 300 mg/day from green leafy vegetables) were compared to a 7-day low-nitrate diet intervention. Outcome measures included pre- and postintervention salivary and plasma nitrate and nitrite concentrations; ambulatory, home, and office blood pressure; augmentation index; and carotid-femoral pulse wave velocity. The high-nitrate diet intervention resulted in at least a fourfold increase in salivary and plasma nitrate and nitrite (P<0.001). Ambulatory, home, and office blood pressure and arterial stiffness were not different between the high-nitrate diet and the low-nitrate diet. Increasing dietary nitrate intake in those with high-normal blood pressure and at increased risk of hypertension may not be an effective short-term strategy to lower blood pressure.
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, WA 6000, Australia. Electronic address: cbondonno@meddent.uwa.edu.au.
authors.forename: Catherine P
authors.initials: CP
authors.lastname: Bondonno
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, WA 6000, Australia.
authors.forename: Alex H
authors.initials: AH
authors.lastname: Liu
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, WA 6000, Australia.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Croft
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, WA 6000, Australia.
authors.forename: Natalie C
authors.initials: NC
authors.lastname: Ward
authors.affiliation: School of Plant Biology, University of Western Australia, Perth, WA 6000, Australia.
authors.forename: Xingbin
authors.initials: X
authors.lastname: Yang
authors.affiliation: College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an, China; Department of Agriculture and Food Western Australia, South Perth, WA, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Considine
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, WA 6000, Australia.
authors.forename: Ian B
authors.initials: IB
authors.lastname: Puddey
authors.affiliation: Flinders Centre for Epidemiology and Biostatistics, Flinders University, Adelaide, SA, Australia.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Woodman
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, WA 6000, Australia.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Hodgson
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D006973:Hypertension / Q000178:diet therapy* / Q000473:pathology / Q000652:urine; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000652:urine; D012964:Sodium / Q000652:urine; D018724:Spinacia oleracea / Q000378:metabolism*; D016896:Treatment Outcome; D059289:Vascular Stiffness
chemical_list: D012964:Sodium; D003404:Creatinine; D011188:Potassium
keywords: Arterial stiffness; Blood pressure; Free radicals; Green leafy vegetables; Nitrate