An excessive consumption of caffeine can have serious consequences on the health of the serial drinker. According to the "Scientific Opinion on the safety of caffeine", a report drafted by the European Food Safety Authority (EFSA), drinking more than 5 cups of coffee a day can cause cardiac diseases, high blood pressure, insomnia, nervousness and panic attacks. The paper's authors estimate that the daily caffeine intake of an healthy adult should be up to 400 milligrams. For pregnant women the recommended intake is even lower: up to 200 milligrams a day.
Although caffeine is mainly found in coffee (one cup contains an average of 90 milligrams), we should pay attention to other caffeine sources, such as tea (60 mg/cup), energy drinks (80 mg), non-alcoholic drinks and chocolate (25 mg per dark chocolate tablet and 10 mg per milk chocolate tablet).