What do you think about a cup of coffee ? is it good or bad for our health ?

A cup of coffee within a day is good for my aging prevention. More than a cup of coffee within a day will threat and hurt our health. This is my philosophy. In the past experiment, the white rats with caffeine and without caffeine were both exposed to the radiation. Only the white rat WITHOUT the caffeine was in cancer. I drank too much of coffee in few days. During the night, I couldn't sleep. I could feel my fast heart beats. My heart was liked dropping out from my chest. Later, I read an article in the newspaper, then I realized that it was caused by drinking too much of coffee. I was poisoned by caffeine and the coffee contains high caffeine.