Does Drinking Tea Protect Against Cardiovascular Disease?

摘要

Recent evidence supports the hypothesis that tea does, in fact protect against cardiovascular disease. Some of the latest data by Hodgson et al, suggests that dietary flavonoids in tea significantly improves endothelium-dependent and endothelium-independent flow-mediated vasodilation (2.3%; P=.008 & 4.2%; P=.03 respectively). Similar results were obtained in a study by Duffy et al, where it was found that short- and long-term tea consumption significantly improved endothelium dependent flow-mediated vasodilation (P<.001). Such improvement in endothelial function is a likely mechanism by which tea exerts its protective effects. Geleijnse et al found that drinking at least 375 mL of tea per day reduced the risk of having a heart attack (RR: 0.57; 95%CI: 0.33, 0.98) compared to not drinking tea. However, previous studies failed to show that tea was preventive of heart attack. In another study, Mukamal et al found that moderate and heavy tea drinkers had lower mortality after heart attack (hazard ratio: 0.69; 95% CI: 0.53, 0.89 & hazard ratio: 0.61; 95% CI 0.42, 0.86 respectively). These studies have several limitations, however, that must be addressed in further research to clearly determine whether tea might help prevent cardiovascular disease and how it might exert such effects.