Black and green tea do contain caffeine, but quite a bit less: http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20

Black and green tea do contain caffeine, but quite a bit less: http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20049372 http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-he... It depends a bit on the specific preparation but black tea contains at most half as much caffeine as brewed coffee (per liter) and green tea is again half as much. Thus an easy way to reduce your caffeine intake is to replace a cup coffee by a cup of the same size of black tea and maybe later green tea (you are not going to drink twice as much liquid and are not drastically cutting your caffeine intake).