Black Tea Increases Circulating Endothelial Progenitor Cells and Improves Flow Mediated Dilatation Counteracting Deleterious Effects from a Fat Load in Hypertensive Patients: A Randomized Controlled Study

Abstract

(1) Background: Endothelial dysfunction predicts cardiovascular events. Circulating angiogenic cells (CACs) maintain and repair the endothelium regulating its function. Tea flavonoids reduce cardiovascular risk. We investigated the effects of black tea on the number of CACs and on flow-mediated dilation (FMD) before and after an oral fat in hypertensives; (2) Methods: In a randomized, double-blind, controlled, cross-over study, 19 patients were assigned to black tea (150 mg polyphenols) or a placebo twice a day for eight days. Measurements were obtained in a fasted state and after consuming whipping cream, and FMD was measured at baseline and after consumption of the products; (3) Results: Compared with the placebo, black tea ingestion increased functionally active CACs (36 ± 22 vs. 56 ± 21 cells per high-power field; p = 0.006) and FMD (5.0% ± 0.3% vs. 6.6% ± 0.3%, p < 0.0001). Tea further increased FMD 1, 2, 3, and 4 h after consumption, with maximal response 2 h after intake (p < 0.0001). Fat challenge decreased FMD, while tea consumption counteracted FMD impairment (p < 0.0001); (4) Conclusions: We demonstrated the vascular protective properties of black tea by increasing the number of CACs and preventing endothelial dysfunction induced by acute oral fat load in hypertensive patients. Considering that tea is the most consumed beverage after water, our findings are of clinical relevance and interest.

Effects Of Tea Consumption On Measures Of Cardiovascular Disease: A Systematic Review Of Meta-Analysis Studies And Randomised Controlled Trials

“…For black tea those with a higher cardiovascular risk appear to have more benefit [11] with indications from RCTs suggesting that black tea could reduce triglyceride levels, alter body fat distribution and increase fat excretion [6,40,44]. For black tea there is evidence that this can improve FMD and exhibit vascular protective properties that could be of clinical relevance [48,49,53]. Although these effects appear to be modest they could be of importance for cardiovascular health at the population level due to the widespread habitual consumption of tea and high prevalence of cardiovascular risk factors.…”

“…Pang et al [45]; Tang et al [46] Grassi et al [48]; Schreuder et al [49]; Grassi et al [53] Inflammation Meta-analytical evidence looking at tea intake in relation to markers of inflammation is lacking.…”

“…Six RCTs focused on aspects of CV function [48][49][50][51][52][53]. A small 8-day trial providing black tea (150 mg polyphenols) twice daily noted improvements in circulating angiogenic cells (CACs) and flowmediated dilation (FMD), with a maximal response 2 hours after ingestion [48]. A 7-day trial of 20 healthy subjects drinking 3 cups black tea per day also observed improvements in FMD with this appearing to relate to a direct effect of the tea on the endothelium [49].…”

Health Functions and Related Molecular Mechanisms of Tea Components: An Update Review

“…It was reported that short-term daily consumption of three capsules containing 500 mg of green tea extract could reduce blood pressure in obese prehypertensive women [135]. In addition, tea consumption also improved the endothelial function in humans, and green and black teas may be equally effective with regard to improve endothelial function [136][137][138][139][140]. Acute black tea intake (200 mL/day) for seven days enhanced the cutaneous vascular response to gradual local heating to 42 • C in healthy, middle-aged participants, which was probably induced by activating endothelium-derived chemical mediators like NO [136].…”

Modulation of Adhesion Process, E-Selectin and VEGF Production by Anthocyanins and Their Metabolites in an In Vitro Model of Atherosclerosis

“…In recent years, polyphenols have received extensive interest for their health benefits in the prevention of numerous cardiovascular diseases [12][13][14][15][16]. The mechanisms through which polyphenols may exert their bioactivity are not completely understood since it is not clear whether their activity is linked to the native forms, their derivatives or both.…”