Favorable effects of concord grape juice on endothelial function and arterial stiffness in healthy smokers.

BACKGROUND Smoking is associated with impaired vascular function. Concord grape juice (CGJ), a rich source of flavonoids, can modify cardiovascular risk factors. Endothelial function and arterial stiffness are surrogate markers of arterial health. We examined the impact of CGJ on arterial wall properties in healthy smokers. METHODS We studied the effect of a 2-week oral treatment with CGJ in 26 healthy smokers on 3 occasions (day 0 (baseline), day 7, and day 14) in a randomized, placebo-controlled, double-blind, crossover study. Measurements were taken before (pSm), immediately after (Sm0), and 20 minutes after (Sm20) cigarette smoking. Endothelial function was evaluated by flow-mediated dilation (FMD) of the brachial artery. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness. RESULTS Compared with placebo, treatment with CGJ resulted in a significant improvement in pSm values of FMD (P 0.02) and PWV (P 0.04). At baseline, smoking decreased FMD in both the CGJ group (P < 0.001) and the placebo group (P < 0.001). Compared with placebo, CGJ treatment prevented the acute smoking-induced decrease in FMD on day 7 (P 0.02) and day 14 (P < 0.001). Moreover, at baseline, smoking induced a significant elevation in PWV in both the CGJ group (P 0.02) and the placebo group (P 0.04). Treatment with CGJ prevented the smoking-induced elevation in PWV on day 7 (P 0.003) and day 14 (P < 0.001). CONCLUSIONS CGJ consumption improved endothelial function and vascular elastic properties of the arterial tree in healthy smokers and attenuated acute smoking-induced impairment of arterial wall properties.