DALLAS - July 20, 2026 - The American Heart Association has released a new scientific statement on caffeine and cardiovascular disease, concluding that for most adults, consuming up to 400 mg of caffeine per day - equivalent to about five 8-ounce cups of caffeinated coffee - is safe and may be linked to a lower risk of several cardiovascular conditions, including heart failure, heart disease and stroke. However, higher doses, particularly those found in energy drinks and energy shots, may increase the risk of high blood pressure and irregular heart rhythms.
The statement, published in the AHA's flagship journal Circulation, reviews the latest research on caffeine's effects on the cardiovascular system. According to Gregory M. Marcus, M.D., M.A.S., FAHA, chair of the scientific statement writing group, caffeine consumed in coffee is a key part of daily life for millions, and the evidence supports that moderate intake is safe and does not increase cardiovascular risk for most adults. However, he cautioned that high doses of caffeine from energy drinks can have harmful effects.
The writing group noted that studying caffeine's effects is challenging because coffee contains many bioactive compounds, such as antioxidants and anti-inflammatory agents, which may contribute to health benefits. Most studies are observational, meaning they cannot prove cause and effect, and it is difficult to separate caffeine's effects from additives like sugar, cream or flavored syrups, which likely reduce potential benefits.
Key findings include: consuming 2-4 cups of caffeinated coffee per day was linked to a lower risk of heart disease, heart failure and stroke, while more than 4 cups may increase heart failure risk. Caffeinated coffee without additives was associated with a lower risk of Type 2 diabetes, atrial fibrillation, and other arrhythmias. However, randomized trials showed that caffeine consumption also increased the risk of premature ventricular contractions. Higher caffeine intake from energy drinks was associated with cardiovascular harm, including increased blood pressure and arrhythmias, especially in healthy adults under 30.
The statement also highlighted that individual responses to caffeine vary based on genetics, metabolism, age and tolerance. Short-term effects may include temporary increases in blood pressure, heart rate and alertness, but some people may experience palpitations or sleep disruption. The authors emphasized that there is no one-size-fits-all approach and urged individuals to consult their healthcare team.
Additional research is needed on different sources of caffeine, such as tea, soda and energy drinks, and on how additives and genetic factors influence health outcomes. The AHA's 2026 Dietary Guidance did not include caffeine recommendations due to insufficient data, but this statement provides a foundation for future guidelines.
For more information, visit the American Heart Association's website and read the full statement in Circulation online.
