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Background
Hypertension (HPT) is a major risk factor for CVD and related diseases as well as for diseases leading to a marked increase in cardiovascular risk(1).
The WHO reported that high blood pressure (BP) has been listed as the first cause of death worldwide(1) with an age-standardised prevalence of raised BP ranging from 15·2 to 31·7 %, as reported by the European Society of Cardiology in 2014(2). In particular, it has been reported that BP levels show a continuous linear relationship with the risk of stroke and myocardial infarction(2); the INTERHEART study(3) estimated that 22 % of myocardial infarctions in Europe are related to HPT, which almost doubles the risk compared with individuals with no history of HPT.
The relationship of BP with caffeine and caffeine metabolites is a major interest, given the widespread caffeine intake from food and beverage sources and the public health burden of high BP. Caffeine is the most widely consumed active pharmacological substance in the world and it is found also in common non-essential grocery items such as coffee, tea, cocoa, chocolate and soft drinks(4).
Caffeine exerts several effects on the autonomic nervous system and blood vessels. The mechanisms by which caffeine exposure affects heart rate and BP levels might include increased catecholamine levels, which might subsequently lead to vasoconstriction(5,6). Possible mechanisms for the acute cardiovascular effects of caffeine include antagonistic effects on adenosine receptors (particularly, A1 and A2A receptors), activation of the sympathetic nervous system, stimulation of the adrenal cortex (release of corticosteroids), renal effects (diuresis, natriuresis and activation of the renin–angiotensin–aldosterone system) and inhibition of phosphodiesterase(7).
However, the role of caffeine in the regulation of BP levels is controversial. According to the guidelines for the management of arterial HPT of the European Society of Hypertension(8) and of the European Society of Cardiology(8), a firm recommendation or discouragement of coffee consumption cannot be issued due to insufficient quality of most studies(8).
Recently, the European Food Safety Authority (EFSA) Panel on Dietetic Products, Nutrition and Allergies reported its Scientific...