Caffeine, found in many products like coffee, energy drinks, soda, teas and chocolate, is the most commonly consumed stimulant worldwide. An estimated 85% of Americans drink at least one caffeinated beverage daily, with each person consuming an average of 165 mg of caffeine per day — equivalent to about one and a half cups of coffee.
For some, this amount is not enough to stay alert throughout the day, but could turn others into a jittering mess. So how does caffeine affect the body, and why might people react differently to its stimulatory effects?
How Caffeine Affects the Body
While proven safe in reasonably large doses, caffeine is a drug — a substance that changes the body’s mental or physical state. And accomplished caffeine physiologist Astrid Nehlig, Ph.D., Emeritus Research director at the French Institute of Health and Medical Research, explains how it exerts its widely coveted effects.