The psychoactive substance, caffeine,
Is mostly derived from a bean
Or the C. sinensis tree,
If that’s your cup of tea,
For your morning wake-up routine.
The top two worldwide sources of caffeine are coffee and tea. As far as imbibers per capita, Finland is number one for coffee and Turkey is number one for tea. According to Wikipedia, about 85 percent of adult North Americans consumes caffeine daily, mostly from beverages. Check out How the World Gets Its Caffeine Fix for detailed consumption numbers. The physiological effects on the human body, according to CBS, are: a) it blocks sleep-associated adenosine in the brain, b) it replaces adenosine, when it binds to the same receptors on nerve cells, c) it increases metabolic processes, heart rate, blood pressure and tightened muscles, d) it causes blood vessel constriction, and e) it triggers the release of adrenaline.