AHA Says 5 Cups of Black Coffee Are Safe as Over 4 May Raise Heart Failure Risk

3 articles · Updated · Fortune · Jul 20

Up to 5 cups of black caffeinated coffee a day—about 400 mg of caffeine—is safe for most adults, the American Heart Association said in a new Circulation scientific statement.
Two to 4 cups daily were linked to lower risks of heart disease, heart failure and stroke, while intake above 4 cups may start to increase heart failure risk.
The review also found a mixed blood-pressure signal: in adults with healthy blood pressure, 1 to 3 cups were associated with higher hypertension risk, but more than 3 cups were linked to lower risk.
Black coffee drove the apparent benefits; regular intake without sugar, milk or flavorings was also tied to lower long-term type 2 diabetes risk despite short-term reductions in insulin sensitivity.
Tea showed similar associations with lower risks of atrial fibrillation, heart failure and stroke, but energy drinks—at 40 to 69 mg of caffeine per fluid ounce—were tied to higher blood pressure and irregular heart rhythm.