Effects of cranberry juice consumption on vascular function in patients with coronary artery disease

Abstract

Background: Cranberry juice contains polyphenolic compounds that could improve endothelial function and reduce cardiovascular disease risk.

Objective: The objective was to examine the effects of cranberry juice on vascular function in subjects with coronary artery disease.

Design: We completed an acute pilot study with no placebo (n = 15) and a chronic placebo-controlled crossover study (n = 44) that examined the effects of cranberry juice on vascular function in subjects with coronary artery disease.

Results: In the chronic crossover study, subjects with coronary heart disease consumed a research preparation of double-strength cranberry juice (54% juice, 835 mg total polyphenols, and 94 mg anthocyanins) or a matched placebo beverage (480 mL/d) for 4 wk each with a 2-wk rest period between beverages. Beverage order was randomly assigned, and participants refrained from consuming other flavonoid-containing beverages during the study. Vascular function was measured before and after each beverage, with follow-up testing ≥12 h after consumption of the last beverage. Mean (±SD) carotid-femoral pulse wave velocity, a measure of central aortic stiffness, decreased after cranberry juice (8.3 ± 2.3 to 7.8 ± 2.2 m/s) in contrast with an increase after placebo (8.0 ± 2.0 to 8.4 ± 2.8 m/s) (P = 0.003). Brachial artery flow-mediated dilation, digital pulse amplitude tonometry, blood pressure, and carotid-radial pulse wave velocity did not change. In the uncontrolled pilot study, we observed improved brachial artery flow-mediated dilation (7.7 ± 2.9% to 8.7 ± 3.1%, P = 0.01) and digital pulse amplitude tonometry ratio (0.10 ± 0.12 to 0.23 ± 0.16, P = 0.001) 4 h after consumption of a single 480-mL portion of cranberry juice.

Conclusions: Chronic cranberry juice consumption reduced carotid femoral pulse wave velocity-a clinically relevant measure of arterial stiffness. The uncontrolled pilot study suggested an acute benefit; however, no chronic effect on measures of endothelial vasodilator function was found. This trial was registered at clinicaltrials.gov as NCT00553904.

Figures

FIGURE 1

Study design. Upper panel: for the acute pilot study, participants (n = 15) received cranberry juice and vascular testing was repeated 2 and 4 h after juice consumption. Lower panel: for the chronic crossover study, participants were randomly assigned to consume cranberry juice first (upper row; n = 24) or placebo first (lower row; n = 23) and consumed the assigned beverage for 4 wk. After a 2-wk rest period, they then crossed over to the alternate beverage. Two subjects withdrew while consuming cranberry juice because of dyspepsia, and one subject withdrew because of scheduling problems while consuming placebo. A total of 44 subjects completed the study.