New studies linking caffeine use to central nervous system problems and birth defects in test animals have prompted scientists and policy makers in the U.S. to reconsider caffeine's regulatory status. This is a complex task, however, because caffeine is regulated under three different section of the Federal Food, Drug, and Cosmetic Act. It is a natural ingredient in coffee and tea. A food addictive in soft drink, and an added ingredient in over-the-counter drug.