With assistance from Northeastern graduate student Patrick H. Norwood Caffeine is the single most widely used substance in the world over, regardless of age group or cultural background. It is known as a common stimulant. We find it in a variety of foods, including coffee, tea, soda, and chocolate. Given its popularity and social acceptance, many of us come to enjoy at least a modest serving in our daily lives; Americans consume an average of 300 mg per day -- the equivalent of about 2 medium cups of brewed coffee. What, if any, are the health implications of caffeine consumption? And what if, rather than 1 or 2, we drink 5 or 6 cups of coffee each day? Are there major concerns to be had? The short answer is "No." Having a few cups of coffee throughout the day yields nearly the average intake. However, with that said some people may experience a particular hypersensitivity to caffeine even at moderate levels, in which case they may do better by avoiding it. Others, however, m...