title: Daily blueberry consumption improves blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1-hypertension: a randomized, double-blind, placebo-controlled clinical trial.
abstract: BACKGROUND
  Postmenopausal women have a high prevalence of hypertension and often develop arterial stiffness thereby increasing cardiovascular disease risk. Although antihypertensive drug therapies exist, increasing numbers of people prefer natural therapies. In vivo studies and a limited number of clinical studies have demonstrated the antihypertensive and vascular-protective effects of blueberries.
  
  
  OBJECTIVE
  To examine the effects of daily blueberry consumption for 8 weeks on blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1-hypertension.
  
  
  METHODS
  This was an 8-week, randomized, double-blind, placebo-controlled clinical trial.
  
  
  METHODS
  Forty-eight postmenopausal women with pre- and stage 1-hypertension recruited from the greater Tallahassee, FL, area participated.
  
  
  METHODS
  Participants were randomly assigned to receive either 22 g freeze-dried blueberry powder or 22 g control powder.
  
  
  METHODS
  Resting brachial systolic and diastolic blood pressures were evaluated and arterial stiffness was assessed using carotid-femoral pulse wave velocity and brachial-ankle pulse wave velocity. C-reactive protein, nitric oxide, and superoxide dismutase were measured at baseline, 4 weeks, and 8 weeks.
  
  
  METHODS
  Statistical analysis was performed using a split plot model of repeated measures analysis of variance.
  
  
  RESULTS
  After 8 weeks, systolic blood pressure and diastolic blood pressure (131±17 mm Hg [P<0.05] and 75±9 mm Hg [P<0.01], respectively) and brachial-ankle pulse wave velocity (1,401±122 cm/second; P<0.01) were significantly lower than baseline levels (138±14 mm Hg, 80±7 mm Hg, and 1,498±179 cm/second, respectively), with significant (P<0.05) group×time interactions in the blueberry powder group, whereas there were no changes in the group receiving the control powder. Nitric oxide levels were greater (15.35±11.16 μmol/L; P<0.01) in the blueberry powder group at 8 weeks compared with baseline values (9.11±7.95 μmol/L), whereas there were no changes in the control group.
  
  
  CONCLUSIONS
  Daily blueberry consumption may reduce blood pressure and arterial stiffness, which may be due, in part, to increased nitric oxide production.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Johnson
authors.forename: Arturo
authors.initials: A
authors.lastname: Figueroa
authors.forename: Negin
authors.initials: N
authors.lastname: Navaei
authors.forename: Alexei
authors.initials: A
authors.lastname: Wong
authors.forename: Roy
authors.initials: R
authors.lastname: Kalfon
authors.forename: Lauren T
authors.initials: LT
authors.lastname: Ormsbee
authors.forename: Rafaela G
authors.initials: RG
authors.lastname: Feresin
authors.forename: Marcus L
authors.initials: ML
authors.lastname: Elam
authors.forename: Shirin
authors.initials: S
authors.lastname: Hooshmand
authors.forename: Mark E
authors.initials: ME
authors.lastname: Payton
authors.forename: Bahram H
authors.initials: BH
authors.lastname: Arjmandi
mesh_terms: D000368:Aged; D055109:Ankle Brachial Index; D001794:Blood Pressure / Q000502:physiology; D029798:Blueberry Plants; D002097:C-Reactive Protein / Q000378:metabolism; D004311:Double-Blind Method; D005260:Female; D005431:Florida; D005638:Fruit; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000178:diet therapy* / Q000503:physiopathology; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood; D063177:Pulse Wave Analysis; D013482:Superoxide Dismutase / Q000097:blood; D059289:Vascular Stiffness / Q000502:physiology
chemical_list: D009569:Nitric Oxide; D002097:C-Reactive Protein; D013482:Superoxide Dismutase
keywords: Blueberries; Flavonoids; Nitric oxide; Pulse wave velocity; Vasodilation