Effects and Mechanisms of Tea Regulating Blood Pressure: Evidences and Promises

Abstract

Cardiovascular diseases have overtaken cancers as the number one cause of death. Hypertension is the most dangerous factor linked to deaths caused by cardiovascular diseases. Many researchers have reported that tea has anti-hypertensive effects in animals and humans. The aim of this review is to update the information on the anti-hypertensive effects of tea in human interventions and animal studies, and to summarize the underlying mechanisms, based on ex-vivo tissue and cell culture data. During recent years, an increasing number of human population studies have confirmed the beneficial effects of tea on hypertension. However, the optimal dose has not yet been established owing to differences in the extent of hypertension, and complicated social and genetic backgrounds of populations. Therefore, further large-scale investigations with longer terms of observation and tighter controls are needed to define optimal doses in subjects with varying degrees of hypertensive risk factors, and to determine differences in beneficial effects amongst diverse populations. Moreover, data from laboratory studies have shown that tea and its secondary metabolites have important roles in relaxing smooth muscle contraction, enhancing endothelial nitric oxide synthase activity, reducing vascular inflammation, inhibiting rennin activity, and anti-vascular oxidative stress. However, the exact molecular mechanisms of these activities remain to be elucidated.

Anti-hyperglycaemic and insulin-releasing effects of Camellia sinensis leaves and isolation and characterisation of active compounds

“…Camellia sinensis (black tea) gained attention for its polyphenol compounds including epigallocatechin-3-gallate (EGCG), epigallocatechin (EGC), epicatechin-3-gallate (ECG) and epicatechin (EC), which have been reported to have wide range of health promoting effects (12) .…”

A Whole-Diet Approach Affects Not Only Fasting but Also Postprandial Cardiometabolic Risk Markers in Overweight and Obese Adults: A Randomized Controlled Trial

“…Therefore, it is difficult to estimate the exact amount of nitrate from 750 g nitrate-rich vegetables in the HD and to predict to what extent the NO pathway has contributed to the blood pressure reduction. A number of human intervention trials have shown the antihypertensive effect of green and black tea, possibly related to the polyphenolic compounds (flavonoids) present in tea that possess antioxidative properties ( 46 ). Together with the polyphenol-rich vegetables, the regular consumption of tea in the HD group may also have contributed to a lower BP.…”

Habitual Tea Drinking is Associated with Reduced Odds of Restrictive Spirometry Pattern in Non-smokers

“…The three major classes of avonoids are avonols, avones and catechins. Studies either in vitro or ex vivo have shown that tea extracts, such as avonoids and its secondary metabolites, may participate in manipulating the smooth muscle relaxation, nitric oxide synthase activity in endothelial cells, vascular in ammation reduction, and renin activity inhibition through its anti-in ammatory and anti-oxidative effects [17,31]. In addition, studies also showed that avonoids and tea catechins can signi cantly improve endothelial function [32,33].…”

“…Tea is a worldwide popular beverage, and tea consumption has been shown to lead to a reduced risk of cardiovascular disease, hypertension, diabetes, and lung cancer [15][16][17][18]. Twice daily tea consumption at a minimum has been found to be related to a lower risk of COPD [19].…”