Numerous studies have been carried out to determine the effect of caffeine on the cardiovascular system, with inconclusive results. Some have found that the consumption of caffeine increases cardiovascular risk [19–21] while others have described a beneficial or neutral effect on the same [22–24]. It is evident that the cardiovascular response to this substance depends on a variety of factors such as the amount ingested, the time of consumption, the frequency, degree of absorption, and hepatic metabolism, all aspects which cause a unique response of each individual to caffeine [25]. In addition to these factors, it is believed that some substances found in caffeinated beverages (theobromine and theophylline active substances in bronchodilator medications used in the treatment of respiratory diseases) could have some effects on the variability of these particular physiologic responses.
Caffeine is a xanthine which acts in the body’s cells by different mechanisms of action and on a wide range of molecular targets. It intervenes as an antagonist of the adenosine receptors, inhibitor of phosphodiesterase enzymes, sensitizer of calcium liberation channels, and GABA receptor antagonist [26]. Other cardiovascular processes are related to the reduction of cytoplasmic Ca2+ in the vascular smooth muscle cell (VSMC) through cyclic adenosine monophosphate (cAMP) and the increase of the same in the endothelial cell, favoring the synthesis of nitric oxide (NO).
We know that other related substances with a similar structure to that of the alkaloids present in coffee currently provide an important research tool towards the development of potential treatments for Alzheimer disease, asthma, cancer, diabetes, and Parkinson’s disease [14]. In this paper, the main mechanisms of action of caffeine on the vascular tissue are described, and we will try to break a series of myths and paradigms that have negatively influenced the consumption of coffee. These mechanisms are summarized in Table 1.