The American Heart Association (AHA) has released a new scientific statement, published in its flagship journal Circulation, concluding that for most adults, consuming up to 400 mg of caffeine per day—equivalent to about five 8-ounce cups of brewed coffee—is safe and may be linked to a lower risk of several cardiovascular conditions, including heart failure, heart disease, and stroke. However, the statement warns that higher doses of caffeine, particularly from energy drinks and shots, can increase the risk of high blood pressure and irregular heart rhythms.
The statement, titled “Caffeine and Cardiovascular Disease,” reviewed the latest research on caffeine's impact on heart health. According to the writing group chair, Dr. Gregory M. Marcus, a professor of medicine at the University of California, San Francisco, “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 ... is safe and does not increase cardiovascular risk.” However, he emphasized that high doses from energy drinks should be avoided due to potential harm.
Key findings from the statement include that drinking 2–4 cups of caffeinated coffee per day was associated with a lower risk of heart disease, heart failure, and stroke. Consuming 1–3 cups daily was linked to a reduced risk of atrial fibrillation but also to a higher risk of premature ventricular contractions. The statement also notes that adding sugar, cream, or flavored syrups likely diminishes health benefits.
In contrast, energy drinks and shots, which can contain 3–4 times more caffeine per ounce than coffee, were associated with increased blood pressure and arrhythmias, even in healthy young adults. The statement calls for more research into these products.
The AHA statement highlights that individual responses to caffeine vary based on genetics, metabolism, age, and medications. It advises people to monitor their own reactions and consult healthcare providers. The statement did not set official guidelines but noted that caffeine was not included in the AHA’s 2026 Dietary Guidance due to insufficient data for specific recommendations.
This statement updates earlier research and underscores that coffee's benefits may stem from compounds other than caffeine, such as antioxidants. The AHA emphasizes the need for more randomized trials to clarify cause and effect, especially for energy drinks and other caffeinated products.
