Current hypertension guidelines lack in recommendations on coffee consumption. We therefore review the available data on the relationship of coffee intake and blood pressure with underlying mechanisms.
Design and method:
A literature review on coffee intake and blood pressure till November 2017 in English was performed using PubMed, Web of Science and Embase database.
Cross-sectional studies incline to null or negative association between BP level or hypertensive prevalence and habitual coffee intake. Prospective studies figure out an inverse liner or inverse U-shape relationship between long-term coffee consumption and hypertension risk among males free from cigarettes and premenopause females. Compared with the lowest consumption (<1 cup/d), coffee intake with 3∼4cups/d parallel hypertension risk, while higher consumption (>3∼4cups/d) decrease the risk of hypertension. Clinical trials proved: 1) Acute BP elevation directed by caffeine (3 h) 2) Moderate or inverse BP elevation after coffee intake over 7 days 3) Protective effect of coffee on BP among habitual coffee intake under mental stress or long-term alcohol consumption. Key possible mechanisms include 1)CYP1A2 gene and enzyme associated with inverse connection between BP and coffee via inhibition of adenosine receptor in nonsmoking population 2) Inhibition of sodium and water reabsorption through AMPK/alpha-ENaC pathway directed by caffeine 3) Inhibition of inflammation, oxidant stress and RAAS via chorogenic acids.
Coffee intake is not suggested before blood pressure measurement and in those with high cardiovascular risk and unstable BP. Habitual coffee intake probably be protective over 3∼4 per cups/d among habitual alcohol intake or nonsmoking males and premenopause females, mainly related to gene, caffeine and chorogenic acids.