Acute Effects of an Anthocyanin-Rich Blackcurrant Beverage on Markers of Cardiovascular Disease Risk in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled, Crossover Trial

Background: Epidemiologic evidence suggests an inverse association between anthocyanin consumption and cardiovascular disease (CVD) risk. Modulation of vascular function and hemostasis may contribute to this, but there is limited clinical evidence. Objectives: The present study investigated the acute effects of an anthocyanin-rich blackcurrant beverage, compared with a matched placebo, on selected markers of CVD risk in healthy middle-aged subjects in response to a high-fat meal. Methods: Twenty-three volunteers aged 39.9 +/- 8.1 y [body mass index (BMI) (in kg/m2) 22.9 +/- 2.3] completed a double-blind, randomized, placebo-controlled, crossover trial. Volunteers consumed either a 200 mL blackcurrant beverage (744 mg polyphenols comprising 711 mg anthocyanins and 32 mg procyanidins) or a placebo, together with a high-fat breakfast (52.3 g fat) followed by a lunch (30 g fat) at 3 h, and the postprandial vascular response was compared. The primary endpoints were the assessment of vascular function by flow-mediated dilation (FMD) and the inhibition of collagen-and adenosine diphosphate-induced platelet aggregation. Secondary outcomes included blood pressure (BP), digital volume pulse waveforms, circulating numbers of endothelium-and platelet-derived extracellular vesicles, plasma concentrations of interleukin (IL)-8, and plasma and urinary concentrations of polyphenols and their metabolites were also evaluated. Results: There was a significant cumulative improvement in FMD following consumption of an anthocyanin-rich blackcurrant beverage compared with a matched placebo in conjunction with a high-fat meal over a 6 h postprandial period. There was a trend for an inhibitory effect of the blackcurrant beverage on agonist-induced platelet aggregation and significant effects on the secondary outcomes, systolic BP and IL-8, although these were exploratory and not adjusted for multiple testing. Plasma concentrations of hippuric acid and isovanillic acid were strong independent predictors of FMD, and 4-hydroxybenzaldehyde and isoferulic acid glucuronide were predictors of systolic BP and diastolic BP. Conclusions: An anthocyanin-rich blackcurrant beverage mitigates the effects of a high-fat meal on vascular function and markers of CVD risk, and this is associated with the appearance of specific plasma anthocyanin phenolic metabolites. This trial was registered at classic.clinicaltrials.gov as NCT02459756.