Answered by Chryso Kartsimadis on Monday, June 1, 2009
Cup for cup, coffee comes out on top, but don't underestimate tea's buzz potential. "A six-ounce cup of coffee contains one hundred milligrams of caffeine, while tea has only forty milligrams," explains Manfred Kroger, Ph.D., professor of food science at Pennsylvania State University. Although that's a significantly lower amount, a person whose body metabolizes caffeine slowly will definitely feel the stimulant effects hours later because the caffeine will still be present in the bloodstream. "It all has to do with how fast the body can get rid of the material," Kruger says, "and that varies from person to person." When it comes to other caffeinated goods, the average 12-ounce soft drink stacks up to tea with 40 milligrams per serving; a one-ounce bar of Hershey's chocolate contains six milligrams of caffeine, and a No-Doz tablet contains 100 milligrams (the same as a cup of coffee).