An acute uncontrolled study (n = 15) and a chronic placebocontrolled crossover study (n = 44) were conducted to examine the effects of cranberry juice on vascular function in subjects with coronary artery disease. In the acute study, brachial artery flow-mediated dilation (P = 0.01) and digital pulse amplitude tonometry ratio (P = 0.001) improved four hours after consumption of a single 480-mL portion of cranberry juice. In the chronic crossover study, subjects with coronary heart disease consumed cranberry juice (54% juice, 835 mg total polyphenols, and 94 mg anthocyanins) or a matched placebo beverage for four weeks each, with a two-week washout period. Mean carotid-femoral pulse wave velocity, which is a measure of central aortic stiffness, decreased after cranberry juice compared to an increase after placebo (P = 0.003) but brachial artery flow-mediated dilation, digital pulse amplitude tonometry, blood pressure, and carotidradial pulse wave velocity did not change. Therefore, an acute benefit of cranberry juice consumption was noted while chronic cranberry juice consumption was found to reduce carotid femoral pulse wave velocity with no further effects noted on endothelial vasodilator function. Am J Clin Nutr. 2011 May;93(5):934-40. PMID: 21411615.
