Just like the title says, a new study from Tufts in conjunction with HHS, part of which you can find over here, links a cup of black, caffeinated coffee a day to a decrease in all-cause mortality of about 16% and, after that, 2-3 cups a day of black coffee go a little further. Especially for cardiovascular disease, but I believe for everything (coffee has massive antioxidant properties). The catch is, it has to be black, caffeinated coffee. No decaf, as little as possible sugar, and hardly any creamer (though adding any creamer and sugar drops the statistic to 14%). Those in the study who drank their coffee with any kind of creamer or sugar had much less of a change in their mortality rate, and those who drank it decaffeinated had no change.
Hail the bean!