A team of researchers from Qatar and Egypt reviewed 38 studies covering nearly 2.9 million people to answer a question that sounds simple but isn’t: is coffee good or bad for the heart? The answer, published in BMC Cardiovascular Disorders, depends entirely on which cardiovascular problem you’re looking at.
Heart attack is coffee’s less flattering side. Pooling data from six studies on myocardial infarction, the researchers found a clear association between high coffee intake and a higher risk of having one, a 48% increased risk when comparing the heaviest coffee drinkers with the lightest. Unlike other results in the study, this one showed barely any variation across the different studies analyzed, which gives it extra weight.
But stroke tells the opposite story. When the analysis focused on stroke, the pattern flipped. High coffee intake was linked to a significantly lower risk of stroke, especially the ischemic kind, the most common variety. The same wasn’t true for hemorrhagic strokes, where no relationship was found at all.
Arrhythmias also came out ahead, though with important caveats. Pooling three studies on arrhythmias in general, high coffee intake appeared linked to a lower risk. However, when researchers drilled down into specific arrhythmia types (atrial fibrillation, supraventricular tachycardia, ventricular tachycardia), that protection stopped being statistically significant. That’s a sign the overall result should be taken with caution.
In patients with hypertension, caffeine was even linked to fewer deaths. This may be the study’s most striking finding: among people with hypertension, high caffeine intake was linked to 32% fewer cardiovascular deaths compared with low intake. That relationship didn’t show up in the general population or in people with diabetes or prediabetes, suggesting the effect is specific to that group.
No link was found with coronary heart disease in general or with heart failure. Despite both being among the most common cardiovascular conditions, neither showed a statistically significant association with coffee consumption across the pooled studies.
The authors themselves insist this isn’t a simple story of “good” or “bad.” The researchers describe coffee and caffeine’s cardiovascular effects as “complex and outcome-specific, rather than consistently harmful or beneficial.” Their practical conclusion is that broadly restricting coffee in a healthy population is probably not justified, while moderation would make sense for people with already-diagnosed ischemic heart disease or particular sensitivity to caffeine.
This is correlation, not a controlled experiment, and that matters. The 38 included studies are mostly cohort studies and some case-control studies, not randomized clinical trials. The authors themselves flag several limitations: coffee and caffeine intake was measured through self-report, recorded at a single point in time without tracking how habits changed over time, only studies published in English were included, and the definition of “high intake” varied widely from study to study (in some, “high” meant 2 cups a day; in others, 8). All of this means the associations found are statistically solid, but they don’t prove direct causation.
About this article. This piece is based on the scientific study “Coffee, caffeine, and cardiovascular health: navigating risks and benefits, an updated systematic review and meta-analysis,” by Shaban EE, Elmelliti H, Shaban A, Shaban A, Elkandow A, Abdelrahim MG and Zaki HA, published in 2026 in BMC Cardiovascular Disorders, open access under a CC BY-NC-ND license. DOI: 10.1186/s12872-026-05693-0.
