title: Effects of Concord grape juice on ambulatory blood pressure in prehypertension and stage 1 hypertension.
abstract: BACKGROUND
  Consumption of flavonoid-containing foods may be useful for the management of hypertension.
  
  
  OBJECTIVE
  We investigated whether 100% Concord grape juice lowers blood pressure in patients with prehypertension and stage 1 hypertension.
  
  
  METHODS
  We conducted a double-blind crossover study to compare the effects of grape juice (7 mL · kg⁻¹ · d⁻¹) and matched placebo beverage on 24-h ambulatory blood pressure, stress-induced changes in blood pressure, and biochemical profile. Participants consumed each beverage for 8 wk with a 4-wk rest period between beverages. They ceased consumption of grapes and other flavonoid-containing beverages throughout the study.
  
  
  RESULTS
  We enrolled 64 otherwise healthy patients taking no antihypertensive medications (31% women, 42% black, age 43 ± 12 y). Baseline mean (± SD) cuff blood pressure was 138 ± 7 (systolic)/82 ± 7 (diastolic) mm Hg. No effects on the primary endpoint of 24-h mean systolic blood pressure, diastolic blood pressure, or stress-induced changes in blood pressure were observed. A secondary endpoint was nocturnal dip in systolic pressure. At baseline, nocturnal pressure was 8.3 ± 7.1% lower at night than during daytime. The mean nocturnal dip increased 1.4 percentage points after grape juice and decreased 2.3 percentage points after placebo (P = 0.005). Fasting blood glucose was 91 ± 10 mg/dL at baseline for the entire cohort. Glucose decreased 2 mg/dL after consumption of grape juice and increased 1 mg/dL after consuming the placebo (P = 0.03).
  
  
  CONCLUSIONS
  We observed no effect of grape juice on ambulatory blood pressure in this cohort of relatively healthy individuals with modestly elevated blood pressure. Secondary analyses suggested favorable effects on nocturnal dip and glucose homeostasis that may merit further investigation. This trial was registered at clinicaltrials.gov as NCT00302809.
authors.affiliation: Evans Department of Medicine and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA.
authors.forename: Mustali M
authors.initials: MM
authors.lastname: Dohadwala
authors.forename: Naomi M
authors.initials: NM
authors.lastname: Hamburg
authors.forename: Monika
authors.initials: M
authors.lastname: Holbrook
authors.forename: Brian H
authors.initials: BH
authors.lastname: Kim
authors.forename: Mai-Ann
authors.initials: MA
authors.lastname: Duess
authors.forename: Aaron
authors.initials: A
authors.lastname: Levit
authors.forename: Megan
authors.initials: M
authors.lastname: Titas
authors.forename: William B
authors.initials: WB
authors.lastname: Chung
authors.forename: Felix B
authors.initials: FB
authors.lastname: Vincent
authors.forename: Tara L
authors.initials: TL
authors.lastname: Caiano
authors.forename: Alissa A
authors.initials: AA
authors.lastname: Frame
authors.forename: John F
authors.initials: JF
authors.lastname: Keaney
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Vita
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D008517:Phytotherapy; D028321:Plant Preparations / Q000494:pharmacology / Q000627:therapeutic use*; D027843:Vitis
chemical_list: D000959:Antihypertensive Agents; D001786:Blood Glucose; D028321:Plant Preparations