Does caffeine affect cardiovascular responses

textabstractCaffeine (1,3,7-trimethylxanthine), a natural alkaloid present in many beverages such as coffee, tea and cola drinks, is the most widely consumed pharmacological compound. Due to its common use and frequent intake in stressful conditions, a great deal of data have been produced by epidemiological surveys and experimental mammal studies to evaluate its direct and side effects on the cardiovascular system. There are controversies concerning the possible adverse effects induced by the normal use of caffeine (200-600 mg/day), but a number of negative consequences have been associated with the caffeine present in herbal supplements, beverages and junk food. In this review, we discuss the possible mechanisms involved in the beneficial and detrimental cardiovascular effects of caffeine.