Black coffee

Coffee grains contain from 1,1 to 1,5% of caffeine. The cup of the drink made from ground coffee (150 ml) contains about 120 mg of caffeine . Nevertheless, in instant coffee it makes about 65 mg of caffeine. Most of experts believe that they consumption of 300-400 mg of caffeine a day (that makes about 3-4 cups of coffee a day) do not exert negative impact on health of the person. The exact assessment a toxic dose of caffeine difficult also depends on many factors. A lethal dose of caffeine it is high - 10 g which can be transformed to 80 cups of coffee a day!