School of Medicine and Pharmacology, The University of Western Australia-M570, 35 Stirling Highway, Crawley, WA 6009, Australia.
Food Funct. 2012 Jun;3(6):575-91. doi: 10.1039/c2fo10288a.
Tea and coffee have been associated with risk of cardiovascular disease (CVD), both positively and negatively. Epidemiological data suggest that black and green tea may reduce the risk of both coronary heart disease and stroke by between 10 and 20%. Experimental and clinical trial data generally indicate either neutral or beneficial effects on risk factors and pathways linked to the development of CVD. Controversy still exists regarding the effects of coffee, where there have been concerns regarding associations with hypercholesterolaemia, hypertension and myocardial infarction. However, long term moderate intake of coffee is not associated with detrimental effects in healthy individuals and may even protect against the risk of developing type 2 diabetes. The detrimental effects of coffee may be associated with the acute pressor effects, most likely due to caffeine at high daily intakes, and lipids from boiled coffee can contribute to raised serum cholesterol. Genetic polymorphisms in enzymes involved in uptake, metabolism and excretion of tea and coffee compounds are also associated with differential biological effects. Potential mechanisms by which tea and coffee phytochemicals can exert effects for CVD protection include the regulation of vascular tone through effects on endothelial function, improved glucose metabolism, increased reverse cholesterol transport and inhibition of foam cell formation, inhibition of oxidative stress, immunomodulation and effects on platelet function (adhesion and activation, aggregation and clotting). The phytochemical compounds in tea and coffee and their metabolites are suggested to influence protective endogenous pathways by modulation of gene-expression. It is not known exactly which compounds are responsible for the suggestive protective effects of tea and coffee. Although many biologically active compounds have been identified with known biological effects, tea and coffee contain many unidentified compounds with potential bioactivity.
茶和咖啡与心血管疾病（CVD）的风险有关，既有正面影响也有负面影响。流行病学数据表明，黑茶和绿茶可能降低冠心病和中风的风险 10%至 20%。实验和临床试验数据通常表明，它们对与 CVD 发展相关的风险因素和途径具有中性或有益的影响。关于咖啡的影响仍存在争议，人们担心咖啡与高胆固醇血症、高血压和心肌梗死有关。然而，长期适量饮用咖啡不会对健康个体产生有害影响，甚至可能有助于预防 2 型糖尿病的风险。咖啡的有害影响可能与急性升压作用有关，这很可能是由于高日常摄入量的咖啡因，以及煮沸咖啡中的脂质会导致血清胆固醇升高。参与茶和咖啡化合物摄取、代谢和排泄的酶的遗传多态性也与不同的生物学效应有关。茶和咖啡植物化学物质发挥 CVD 保护作用的潜在机制包括通过影响内皮功能调节血管张力、改善葡萄糖代谢、增加逆向胆固醇转运和抑制泡沫细胞形成、抑制氧化应激、免疫调节和对血小板功能的影响（粘附和激活、聚集和凝血）。茶和咖啡中的植物化学化合物及其代谢物通过调节基因表达来影响保护性内源性途径。目前还不清楚哪些化合物是茶和咖啡具有提示性保护作用的确切原因。虽然已经确定了许多具有已知生物学效应的生物活性化合物，但茶和咖啡中还含有许多具有潜在生物活性的未鉴定化合物。
