The American Heart Association has issued 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 5 cups of brewed coffee—is safe and may even be linked to a lower risk of heart disease, stroke, heart failure, and Type 2 diabetes. However, the statement warns that higher doses, particularly those found in energy drinks and energy shots, can increase the risk of high blood pressure and irregular heart rhythms.
The statement, published today in the Association’s journal Circulation, was prepared by a volunteer writing group and reviews the latest research on caffeine’s effects on cardiovascular conditions. Chair of the writing group, Dr. Gregory M. Marcus, noted that coffee is a key part of daily life for millions, and the evidence supports that moderate intake is safe. However, he emphasized that “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 statement acknowledges challenges in studying caffeine’s effects, as coffee contains many bioactive compounds that may contribute to health benefits, and most studies are observational. It also notes that additives like sugar, cream, and flavored syrups likely diminish potential benefits. Key findings include that 1–3 cups of coffee daily may lower the risk of atrial fibrillation but also increase premature ventricular contractions, and that unfiltered coffee (e.g., espresso, French press) contains cafestol, which can raise LDL cholesterol. Energy drink shots, which contain 3–4 times more caffeine than regular coffee per ounce, were linked to significant blood pressure increases and arrhythmias, especially in younger adults.
Dr. Marcus stressed that there is no one-size-fits-all approach to caffeine, as individual responses vary based on genetics, metabolism, age, and medications. The statement calls for more research on different caffeine sources and their long-term effects, particularly energy drinks. The Association’s findings are part of ongoing efforts to provide evidence-based guidance, though the statement does not set official recommendations. For more details, the full scientific statement is available online at https://www.ahajournals.org/doi/10.1161/CIR.0000000000001234.
The American Heart Association receives more than 85% of its revenue from non-corporate sources, and its financial information is available at https://www.heart.org/en/about-us/aha-financial-information.
