The American Heart Association (AHA) has released a new scientific statement on caffeine and cardiovascular health, concluding that for most adults, consuming up to 400 mg of caffeine per day—equivalent to about five 8-ounce cups of black caffeinated coffee—is safe and may be linked to a lower risk of heart disease, stroke, heart failure, and Type 2 diabetes. The statement, published in the journal Circulation, warns that higher doses, particularly from energy drinks and energy shots, can increase the risk of high blood pressure and irregular heart rhythms.
The writing group, led by Dr. Gregory M. Marcus of the University of California, San Francisco, reviewed the latest research on caffeine's effects. They noted that coffee contains bioactive compounds with antioxidant and anti-inflammatory properties that may contribute to health benefits. However, the cardiovascular effects of coffee are complex and can be influenced by additives like sugar, cream, and flavored syrups, which likely reduce potential benefits.
Key findings from the statement include that 1–3 cups of caffeinated coffee per day were not associated with an increased risk of atrial fibrillation but were linked to more premature ventricular contractions. Higher caffeine intake from energy drinks—which contain 3–4 times more caffeine per ounce than regular coffee—was associated with cardiovascular harm, especially in healthy young adults. The statement also highlighted that unfiltered coffee contains cafestol, which can raise LDL cholesterol, while paper-filtered or instant coffee does not.
Regarding blood pressure, the research showed mixed results: 1–3 cups per day were linked to an increased risk of developing high blood pressure, while more than 3 cups were associated with a lower risk. High doses from energy drinks significantly increased blood pressure, particularly in those with existing hypertension. For Type 2 diabetes, regular consumption of black coffee was linked to a lower risk, though short-term insulin sensitivity may decrease.
Dr. Marcus emphasized that there is no one-size-fits-all approach to caffeine consumption, as individual responses vary based on genetics, metabolism, age, and medications. The AHA's 2026 Dietary Guidance did not include specific caffeine recommendations due to insufficient data, but the statement calls for more research, especially on energy drinks and other caffeinated products.
The full scientific statement is available online at https://www.ahajournals.org/doi/10.1161/CIR.0000000000001234. Additional resources, including video interviews with Dr. Marcus, can be found on the AHA's news release page at https://newsroom.heart.org/news/coffee-and-heart-health-how-many-cups-of-caffeinated-coffee-are-safe-to-drink-each-day.
