What is the reason for and aim of the publication?
This Scientific Statement was produced in order to summarize the latest and best evidence regarding caffeine and cardiovascular disease. The primary goal was to inform the public, scientists, and clinicians about the results of related research, while highlighting limitations of available studies and identifying priorities for future research.
What are the most important take-home messages?
- The majority of research on caffeine and cardiovascular disease has important limitations to recognize. First, most of the research on the topic has focused on caffeinated coffee, presumably and simply because this is the most commonly consumed caffeinated substance. Therefore, it is difficult if not impossible to fully disentangle effects that might be due to caffeine itself versus other constituents in coffee. Second, most of the research is observational, meaning that, even given the most exhaustive and sophisticated adjustment for potential (known and measured) confounders, causality cannot be confidently inferred. Fortunately, more recent randomized trials have been conducted, including testing caffeinated coffee versus avoidance among ambulatory participants.
- The available evidence suggests that regular caffeine consumption, primarily in the form of coffee, is associated with lower risks of diabetes, myocardial infarctions, atrial fibrillation, and stroke. A recent randomized trial provided evidence that, among individuals that usually tolerate caffeinated coffee, assignment to caffeinated coffee resulted in less recurrent atrial fibrillation after cardioversion compared to assignment to avoid coffee and caffeine. Relationships between caffeine and hypertension are more complex, with the strongest evidence suggesting an inverse J-shaped association (higher blood pressure at lower amounts, and lower blood pressure among those consuming larger amounts of caffeine on a regular basis). There does appear to be a higher risk of heart failure among individuals that consume large amounts of caffeine (such as more than 4-5 cups of coffee per day) over a long period of time. Finally, a small, randomized crossover trial provided evidence that caffeine may increase premature ventricular contraction counts.
- While the data on energy drinks and other products with high doses of caffeine or synthetic caffeinated products are much more scant, the available data suggest these substances may cause harm, specifically arrhythmias and heart failure.
- It is important to emphasize that one size does not fit all when it comes to caffeine. Each individual metabolizes caffeine at their own speed, which can vary substantially between people. We all inherit multiple genetic variants that determine how fast (or slow) we metabolize caffeine, and our consumption habits can also influence metabolism (consuming caffeine on a regular basis will tend to ramp up the enzymes that break it down).
What are the challenges in practical implementation – and possible solutions?
The heterogeneity of individual-level tolerance of caffeine and propensities to various diseases coupled with the many effects of caffeine makes providing a simple and universally applicable statement regarding the cardiovascular effects difficult. Future research can help us better predict individualized effects of caffeine, enabling more definitive statements that can be personalized appropriately.
Which issues still need to be tackled that are not yet addressed by the paper?
There are many issues yet to be tackled, with original curiosity-driven research being critical to uncovering these important truths. For example, are there some populations in which caffeine consumption should actually be encouraged? Identifying those most likely to be harmed by caffeine, presumably those prone to ventricular arrhythmias and perhaps heart failure, would be useful. More research on energy drinks certainly needs to be conducted, which may then lead to evidence-based warnings if indeed harms are clearly observed.
What further developments on the topic are emerging?
The complex relationships between genetics and metabolism of caffeine continue to be elucidated, which can help personalize recommendations that optimize health.
Caffeine and Cardiovascular Disease
Marcus GM, Hu FB, van Dam RM, et al. Caffeine and Cardiovascular Disease: A Scientific Statement From the American Heart Association. Circulation. Published online July 20, 2026. doi:10.1161/CIR.0000000000001454
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