Habitual coffee consumption and blood pressure: an epidemiological perspective.

This paper summarizes the current epidemiological evidence on coffee consumption in relation to blood pressure (BP) and risk of hypertension. Data from cross-sectional studies suggest an inverse linear or U-shaped association of habitual coffee use with BP in different populations. Prospective studies suggest a protective effect of high coffee intake (4 or more cups per day) against hypertension, mainly in women. Furthermore, the risk of hypertension may be lower in coffee abstainers. Randomized controlled trials, which are mostly of short duration (1-12 weeks), have shown that coffee intake around 5 cups per day causes a small elevation in BP (approximately 2/1 mmHg) when compared to abstinence or use of decaffeinated coffee. With regard to underlying biological mechanisms, most research has been devoted to BP-raising effects of caffeine. However, there are many other substances in coffee, such as polyphenols, soluble fibre and potassium, which could exert a beneficial effect in the cardiovascular system. Although the precise nature of the relation between coffee and BP is still unclear, most evidence suggests that regular intake of caffeinated coffee does not increase the risk of hypertension.