Caffeine Consumption and the Risk of Breast Cancer in a Large Prospective Cohort of Women

Abstract
Caffeine (1,3,7-trimethylxanthine), a natural purine alkaloid, is probably the most frequently consumed drug in the world.1,2 Common beverages (coffee, tea, and soft drinks), cocoa or chocolate-containing food products, and certain medications, including headache and pain remedies and over-the-counter stimulants, are important sources of caffeine.1,3 In North America, coffee (60%-75%) and tea (15%-30%) are the primary sources of caffeine in the adult diet.1