Current research examines the dual impact of coffee consumption on blood pressure regulation and liver function, highlighting a complex interplay between caffeine and phytochemical compounds.

目前研究探討了咖啡攝取對血壓調節與肝功能的雙重影響，強調了咖啡因與植物化學化合物之間複雜的相互作用。

The cardiovascular implications of coffee are characterized by a dichotomy between acute responses and long-term outcomes. Caffeine acts as a muscle stimulant, inducing the release of adrenaline from the adrenal glands, which results in transient vasoconstriction and an increase in heart rate. This mechanism can elevate systolic and diastolic blood pressure, particularly in non-habitual consumers or individuals with pre-existing hypertension. However, large-scale longitudinal data, including a review of approximately 315,000 participants, indicate no statistically significant correlation between moderate coffee intake and the development of chronic hypertension. A critical exception is noted in populations with grade 2-3 hypertension (systolic ≥160 or diastolic ≥100), where a Japanese study suggests a doubled risk of cardiovascular mortality for those consuming two or more cups daily.

咖啡對心血管的影響特徵在於急性反應與長期結果之間的兩極分化。咖啡因作為一種肌肉刺激劑，會誘發腎上腺分泌腎上腺素，導致暫時性血管收縮並增加心率。這種機制會提升收縮壓與舒張壓，特別是在非習慣攝取者或既有高血壓患者中。然而，包括約 31.5 萬名參與者的的大規模縱向數據顯示，適量攝取咖啡與慢性高血壓的發展之間並無統計學上的顯著相關性。一個關鍵的例外是 2-3 級高血壓人群（收縮壓 ≥160 或舒張壓 ≥100），一項日本研究顯示，每日攝取兩杯或以上咖啡的人，心血管死亡風險將增加一倍。

Conversely, the hepatic effects of coffee are predominantly attributed to non-caffeine constituents. The presence of polyphenols and chlorogenic acid is cited as a primary mechanism for reducing oxidative stress and liver inflammation. Clinical observations by gastroenterological specialists indicate that regular consumption of black coffee is associated with a reduction in liver enzyme levels (ALT and AST) and a diminished risk of liver cirrhosis—estimated in some studies at up to 44%. Furthermore, coffee is identified as a protective agent against non-alcoholic fatty liver disease (NAFLD). Because these benefits are derived from polyphenols rather than caffeine, the hepatoprotective effects are observed in both caffeinated and decaffeinated variants, with an optimal intake identified as two to three cups per day.

相反地，咖啡對肝臟的影響主要歸因於非咖啡因成分。多酚與氯原酸的存在被視為降低氧化壓力與肝臟炎症的主要機制。胃腸科專科醫生的臨床觀察指出，定期飲用黑咖啡與肝酶水平（ALT 和 AST）降低以及肝硬化風險減少相關——部分研究估計最高可降低 44%。此外，咖啡被認定為預防非酒精性脂肪肝（NAFLD）的保護劑。由於這些益處源於多酚而非咖啡因，因此在含咖啡因與脫咖啡因的品種中均可觀察到護肝效果，最佳攝取量為每日兩至三杯。

While coffee exhibits transient hypertensive properties that necessitate caution for high-risk cardiovascular patients, it demonstrates significant protective utility for hepatic health.

雖然咖啡具有暫時性升高血壓的特性，使得心血管高風險患者需加倍小心，但它對肝臟健康展現出顯著的保護效用。