American Heart Association says up to five cups of black coffee daily are safe, but more may raise heart-failure risk
A new American Heart Association statement finds that drinking up to five cups of black coffee a day does not increase cardiovascular risk, while consumption beyond four cups may elevate the chance of heart failure.
The American Heart Association released a scientific statement in its journal Circulation indicating that most adults can safely consume up to five cups of caffeinated coffee a day – roughly 400 mg of caffeine – without increasing cardiovascular risk. The analysis, led by Dr. Gregory Marcus of UC San Francisco Health, emphasized that the coffee should be black, without added sugars or other fillers.
For individuals with normal blood pressure, the study observed a higher likelihood of developing hypertension when drinking one to three cups daily, whereas consuming more than three cups was associated with a lower risk. Drinking two to four cups was linked to reduced rates of heart disease, heart failure and stroke, but intake above four cups appeared to raise the risk of heart failure.
The review also noted that black coffee, consumed regularly and without additives, was associated with a lower long-term risk of type 2 diabetes, despite a short-term reduction in insulin sensitivity. Similar protective associations were reported for tea, which was linked to lower risks of atrial fibrillation, heart failure and stroke.
In contrast, the statement warned that energy drinks, which can contain 40 to 69 mg of caffeine per fluid ounce, are associated with higher risks of hypertension and irregular heart rhythms even in young, healthy adults.
"Up to five cups a day is safe and does not increase cardiovascular risk," Dr. Marcus said.