Abstract P061: Effects of Black Tea With and Without a Fat Load on Vascular Function in Mildly Hypertensive Subjects
Introduction: Endothelial dysfunction is an early biomarker for the development of cardiovascular disease and a predictor of future cardiovascular events. A number of intervention studies in healthy and diseased subjects have reported that endothelial function, as assessed by flow-mediated vasodilation (FMD), is positively affected by black tea consumption. On the other hand, high calorie fatty meals are detrimental to endothelial function.
Hypothesis: To assess the effect of black tea with and without a fat load on FMD, digital volume pulse (DVP) and office blood pressure (BP) in never treated grade 1 hypertensive subjects without additional cardiovascular risk factors.
Methods: According to a randomized, double-blind, controlled, cross-over design, 19 grade 1 hypertensives were assigned to consume black tea, containing 150 mg polyphenols or a placebo drink matched for caffeine, color and taste, twice a day for eight days, with a wash-out period in between of 13 days. On day 7 all measurements were performed in a fasted state, while on day 8 subjects consumed ultra-heat-treated whipping cream (1 gram fat per kg bodyweight) 30 minutes after consuming the test products. FMD, DVP and BP were measured at baseline and 1, 2, 3 and 4 hours after consumption of the test products.
Results: Baseline FMD improved after 1-week tea consumption when compared to placebo (p<0.0001). An additional cup of tea further increased FMD at 1, 2, 3 and 4 hours after consumption when compared to baseline with maximal response 2 hours after intake (p<0.0001). Fat challenge significantly decreased FMD (p<0.0001), which was counteracted by tea consumption. Tea improved reflection index (small vessel tone; p<0.0001) and stiffness index (large arterial stiffness; p<0.0001) with additional effects after acute tea consumption with and without fat load. Further, tea decreased systolic and diastolic BP with and without a fat load (all p<0.0001).
Conclusions: We demonstrate for the first time that moderate consumption of black tea protects against oral fat load-induced endothelial dysfunction in hypertensive but otherwise healthy subjects. The vascular benefits of tea are also reflected in improved endothelial function and peripheral arterial hemodynamics as well as blood pressure lowering under fasted and postprandial conditions. Our findings are of clinical relevance and interest, considering that the ingestion of the main daily meal has been suggested to be a trigger for acute myocardial infarction.
- © 2012 by American Heart Association, Inc.