Coffee and what it does to your body - BBC World Service

Coffee, the world’s most widely consumed psychoactive drug, serves as both a historical catalyst for societal change and a complex biological stimulant. Originating from the *Coffea arabica* plant in Ethiopia, its adoption by 15th-century Sufis and later European coffee houses fueled the Enlightenment by fostering rational discourse and scientific questioning. While coffee historically underpinned the slave trade and the rise of industrial productivity through the "coffee break," it now functions as a $90 billion global industry. Biologically, caffeine mimics adenosine to block relaxation signals, temporarily enhancing alertness, mood, and physical performance. Beyond its stimulant properties, coffee contains antioxidants like chlorogenic acid, which are linked to reduced risks of type 2 diabetes and cardiovascular disease. Optimal benefits are achieved by limiting intake to 400 milligrams daily and avoiding afternoon consumption to maintain receptor sensitivity and sleep quality.