Effects of Concord grape juice on ambulatory blood pressure in prehypertension and stage 1 hypertension.
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.
Dohadwala
Mustali M
MM
Evans Department of Medicine and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA.
Hamburg
Naomi M
NM
Holbrook
Monika
M
Kim
Brian H
BH
Duess
Mai-Ann
MA
Levit
Aaron
A
Titas
Megan
M
Chung
William B
WB
Vincent
Felix B
FB
Caiano
Tara L
TL
Frame
Alissa A
AA
Keaney
John F
JF
Vita
Joseph A
JA
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
D000959:Antihypertensive Agents; D001786:Blood Glucose; D028321:Plant Preparations