Acute effects of beer on endothelial function and hemodynamics: Asingle-blind, crossover study in healthy volunteers
Objective: Moderate consumption of beer is associated with lower cardiovascular (CV) risk. The goal of this study was to determine the effect of beer consumption on CV risk. To explore the underlying mechanisms, we studied the acute effects of the constituents of beer (alcohol and antioxidants), on established predictors of CV risk: endothelial function, aortic stiffness, pressure wave reflections and aortic pressure. Methods: In a randomized, single-blind, crossover study, 17 healthy, non-smoking, men (ages 28.5± 5.2 y with body mass index 24.4 ± 2.5 kg/m2) consumed on three separate occasions, at least 1 wk apart: 1. 400 mL of beer and 400 mL water, 2. 800 mL of dealcoholized beer (same amount of polyphenols as in the 400 mL of beer), and 3. 67 mL of vodka and 733 mL water (same amount of alcohol as in the 400 mL of beer).Each time aortic stiffness (pulse wave velocity), pressure wave reflections (AΙx), aortic and brachial pressure (Sphygmocor device), and endothelial function (brachial flow mediated dilatation) were assessed at fast and 1 and 2 h postprandial. Results: Aortic stiffness was significantly and similarly reduced by all three interventions. However, endothelial function was significantly improved only after beer consumption (average 1.33%, 95% confidence interval [CI] 0.15-2.53). Although wave reflections were significantly reduced by all three interventions (average of beer: 9.1%, dealcoholized beer: 2.8%, vodka 8.5%, all CI within limits of significance), the reduction was higher after beer consumption compared with dealcoholized beer (P= 0.018). Pulse pressure amplification (i.e., brachial/aortic) was increased by all three test drinks. Conclusions: Beer acutely improves parameters of arterial function and structure, in healthy non-smokers. This benefit seems to be mediated by the additive or synergistic effects of alcohol and antioxidants and merits further investigation.