Short-Term Effect of a Wild Blueberry (Vaccinium angustifolium) Drink on Vascular Reactivity and Circulating Adhesion Molecules in Healthy Adults: A Double-Blind, Randomized, Placebo-Controlled, Crossover Trial

Background: Wild blueberries (WB), abundant in (poly)phenols such as anthocyanins and chlorogenic acids, have shown vascular benefits in several preclinical and epidemiological settings. However, evidence from human trials remains limited. This double-blind, randomized, placebo-controlled, crossover trial investigated the effects of the consumption of a WB drink on vascular reactivity and circulating adhesion molecules in healthy young adults. Methods: Participants received 300 mL of a WB drink (30 g of freeze-dried WB powder containing 740 mg total (poly)phenols, 460 mg total anthocyanins and 170 mg chlorogenic acid) or the same amount of a placebo (PL) drink. Blood pressure, heart rate, microvascular reactivity (i.e., reactive hyperemia index, RHI, lnRHI and FRHI) and arterial stiffness (i.e., augmentation index, AIx) were assessed at baseline and 2 h after consumption of the WB and PL drinks using Endo-PAT2000. In addition, plasma circulating adhesion molecules including vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and cluster of differentiation 15 (CD 15 or Lewis x) were analyzed using ELISA. Results: Overall, analysis of variance did not show a significant effect of treatment on the modulation of markers of vascular function and adhesion molecules but revealed an effect of time, with an increase in terms of microvascular reactivity (RHI, p < 0.01; lnRHI, p < 0.05; FRHI, p < 0.001) and augmentation index (AIx, p < 0.01), and a reduction in the circulating levels of VCAM-1 (p < 0.001) following the intake of both WB and PL drinks. Conclusions: In conclusion, the intake of a WB drink failed to affect vascular function in young healthy subjects. Larger-scale and longer-term intervention studies, particularly in individuals at increased cardiovascular risk and in those with vascular dysfunction, are warranted to further explore the role of WB in modulating vascular reactivity.