NEW ENGLAND JOURNAL OF MEDICINE (JULY 23, 2020): A large body of evidence suggests that consumption of caffeinated coffee, the main source of caffeine intake in adults in the United States, does not increase the risk of cardiovascular diseases and cancers. In fact, consumption of 3 to 5 standard cups of coffee daily has been consistently associated with a reduced risk of several chronic diseases.
Coffee and tea have been consumed for hundreds of years and have become an important part of cultural traditions and social life.5 In addition, people use coffee beverages to increase wakefulness and work productivity. The caffeine content of commonly used sources of caffeine is shown in Table 1. For a typical serving, the caffeine content is highest in coffee, energy drinks, and caffeine tablets; intermediate in tea; and lowest in soft drinks. In the United States, 85% of adults consume caffeine daily,6 and average caffeine intake is 135 mg per day, which is equivalent to about 1.5 standard cups of coffee (with a standard cup defined as 8 fluid oz [235 ml]).7 Coffee is the predominant source of caffeine ingested by adults, whereas soft drinks and tea are more important sources of caffeine ingested by adolescents,