Coffee and Its Effects on the Brain

Abstract

Coffee is one of the most widely consumed beverages. The annual amount of coffee consumed per person is 8–12 kg in the Scandinavian Countries, 4.2 kg in USA, and 2.8 in UK. The caffeine content of a cup of coffee ranges from 65 to 360 mg. The main effects of caffeine include a variety of stimulatory effects upon the central nervous system. Coffee influences sleep, but there are individual differences in coffee-attributed sleep disturbances because of additive genetic and environmental effects, other than factors influencing general sleep quality and quantity such as anxiety and depression. Coffee improves short-term memory and speeds up reaction time by acting on the brain’s prefrontal cortex. Coffee improves task-switching performance by enhancing anticipatory processing such as task set updating, presumably through the neurochemical effects of caffeine on the dopaminergic system. Some studies have shown positive effects of regular coffee-drinking on some neurological disorders, such as the Alzheimer’s and the Parkinson’s diseases. Many experiments report that coffee influences parasympathetic and sympathetic discharge, underlining the effects of coffee on the activity of the autonomic nervous system. A moderate consumption of coffee seems not to affect health; coffee can be considered a functional food and future researches could even elucidate the conditions for possible beneficial effects of coffee consumption, such as for the prevention of some neurodegenerative diseases.