• Caffeine is the most consumed stimulant in the world. • It is consumed in the form of coffee and tea. • At present there is no scientific data for promoting or discouraging coffee and/or tea consumption in the daily diet. • Short–term benefits include mental alertness and improved athletic performance. • Short–term adverse effects including headache, anxiety, tremors, and insomnia. • Long–term adverse effects include generalized anxiety disorder and substance abuse disorders. • Long-term benefits are dose–dependent. Caffeine is associated with a reduced risk of Parkinson’s disease, Alzheimer disease, alcoholic cirrhosis, and gout. Coffee, both caffeinated and decaffeinated, is also associated with a lower risk of type 2 diabetes. • Heavy coffee intake may trigger coronary and arrhythmic events in susceptible individuals, although coffee intake is not considered a long–term risk factor for myocardial disease. • Most studies show a modest inverse relationship between coffee consumption and all–cause mortality. • Caffeine withdrawal is a well–documented clinical syndrome with headache being the most common symptom. (Source: Uptodate)