Green tea contains much less caffeine than in coffee. Cup of coffee contains about 130 to 220 mg of caffeine, while green tea - 40-45 mg. This alone is enough to convince us that green tea is a better choice, but there are some other advantages. In fact, a green tea ingredient, which counteract the caffeine. Teanin amino acid contained in green tea increases mental and physical stress, improves mood and has a calming effect. Therefore, although caffeine, green tea actually has a calming effect. Many people have discovered that even if you drink green tea late at night, it does not affect their sleep. Coffee, on the other hand, stimulates the flow of adrenaline. The release of adrenaline, called "stress hormone. It stimulates the reaction "fight or flight" situations are not life-threatening and leads to additional stress. Valorize the body in a state of constant readiness for "fight or flight" leads to exhaustion, characterized by inability to cope with stress and even depending on stimulants such as coffee.