The American Heart Association (AHA) has released a new scientific statement, “Caffeine and Cardiovascular Disease,” published in its flagship journal Circulation, providing updated guidance on caffeine consumption and heart health. The statement concludes that for most adults, consuming up to 400 mg of caffeine per day—equivalent to about 3 to 5 standard 8-ounce cups of black, unsweetened caffeinated coffee—is safe and does not increase cardiovascular risk. In fact, moderate coffee intake is associated with a lower risk of several cardiovascular conditions, including heart failure, heart disease, and stroke.
However, the statement warns that higher doses of caffeine, particularly those found in energy drinks and energy shots, may have harmful cardiovascular effects. Energy drink shots can contain 40-69 mg of caffeine per fluid ounce, three to four times the concentration of regular coffee. Such high doses have been linked to increased blood pressure and irregular heart rhythms, especially in individuals who are otherwise healthy and young.
“Caffeine consumed in coffee is a key part of daily life for millions of people, and in our review of the most recent research, for most adults, intake of up to 400 mg of caffeine/day, the equivalent of up to 5 cups of caffeinated coffee per day without added sugars or fillers, is safe and does not increase cardiovascular risk,” said Dr. Gregory M. Marcus, chair of the statement writing group and professor of medicine at UCSF. “However, high doses of caffeine, such as those found in energy drinks including energy shots, may have harmful effects on the heart and should be avoided.”
The writing group reviewed recent studies on caffeine’s effects on blood pressure, cholesterol, Type 2 diabetes, coronary heart disease, stroke, heart failure, and arrhythmias. Key findings include: drinking 1–3 cups of coffee daily was associated with a temporary increase in blood pressure in people with optimal blood pressure, but more than 3 cups was linked to lower risk. Black coffee consumption was tied to lower risk of Type 2 diabetes, though short-term insulin sensitivity may decrease. Unfiltered coffee (espresso, French press) contains cafestol, which can raise LDL (“bad”) cholesterol, unlike filtered coffee. Moderate coffee intake (1–3 cups) was not linked to increased atrial fibrillation risk but may increase premature ventricular contractions. Two to four cups daily was associated with lower risk of heart disease, heart failure, and stroke, while more than 4 cups may increase heart failure risk.
The statement emphasizes that not all caffeine sources are equal. Tea has shown similar benefits to coffee for reducing atrial fibrillation, heart failure, and stroke. Energy drinks often contain added ingredients that may accelerate caffeine absorption and amplify cardiovascular effects. The authors call for more randomized controlled trials, especially on energy drinks and other caffeinated products, to better understand their health impacts.
“There is no ‘one-size-fits-all’ strategy for safe caffeine consumption,” Marcus said. “People can respond very differently based on age, medications, genetics, and metabolism. It’s important to pay attention to how your body responds and talk with your healthcare team.” The statement aligns with the AHA’s 2026 Dietary Guidance to Improve Cardiovascular Health, which did not include specific caffeine recommendations due to insufficient data. More information on the AHA’s guidelines is available at heart.org.
This scientific statement was prepared by the AHA’s Council on Lifestyle and Cardiometabolic Health, the Council on Clinical Cardiology, and the Stroke Council. It is intended to inform healthcare decisions and highlight areas needing further research, not to provide specific treatment recommendations.
