Brain scans confirm what many coffee drinkers already know - caffeine perks them up.
Caffeine is the world's most widely used stimulant, according to the research presented at the annual meeting of the Radiological Society of North America. Global daily consumption of caffeine averages 76mg, equal to one-and-a-half cups of coffee. In the United States, average consumption is 238mg per day, equal to that found in four-and-a-half cups of java.
In monetary terms, coffee is the second most traded commodity in the world, trailing only petroleum. Coffee is one of mankind's chief sources of caffeine, a stimulant.