A single portion of blueberries can affect peripheral arterial tone in young smokers with endothelial dysfunction: preliminary observations and perspectives

Background: Cigarette smoke adversely affects vascular function by promoting endothelium injury via reactive oxygen species and nitric oxide dysregulation. Emerging evidence suggests an important role of dietary factors in modulating endothelial function. In particular, blueberries (Vaccinium corymbosum) appear to have beneficial effects on peripheral arterial dysfunction induced by acute cigarette smoking in young healthy volunteers. Objective: The aim of this study is to investigate the possible effect of one portion of blueberries on peripheral arterial function in young smokers with endothelial dysfunction. Methods: The study involves 16 male smokers with endothelial dysfunction. Subjects are randomized in a 3-armed controlled study with the following 3 experimental conditions: - smoking (S) treatment (one cigarette); - blueberry treatment (300 g of blueberry) + smoking (BS); - control treatment (300 mL of water with glucose and fructose) + smoking (CS). One week of wash-out period is scheduled between each treatment. Blood pressure (BP), heart rate (HR), and peripheral arterial function (reactive hyperemia index, RHI) are measured before and 20 min after smoking by using finger plethysmography method (Endo-PAT2000). Results obtained are elaborated by analysis of variance (ANOVA). Post-hoc analysis of differences between treatments is assessed by the least significant difference (LSD) test with p ≤ 0.05 as level of statistical significance. Results and Conclusion: Elaboration of preliminary data on 5 subjects showed that smoking does not affect RHI, BP and HR in subjects with endothelial dysfunction differently from what observed in smokers with normal endothelial function. However, ANOVA revealed a significant difference in the effect of the 3 treatments on RHI (p= 0.01). In particular, BS and CS treatments improved RHI index with respect to S treatment (+30.9  24.2% BS vs S, p= 0.0055; +25.3  27.2% CS vs S, p= 0.014). On the contrary, no effect was observed for systolic and diastolic BP, and HR (p= 0.80, p= 0.75 and p= 0.94, respectively). Further analysis of data on the whole group of subjects will help clarifying the protective effect of blueberry consumption in subjects with endothelial dysfunction.