New findings: How much coffee is healthy?

New research suggests that up to five cups of coffee per day can be safe, and possibly beneficial, for most healthy adults. The findings, released by the American Heart Association (AHA), mark a shift in understanding the role of coffee in heart health. This update comes after over 150 years of scientific scrutiny into coffee’s effects, during which its reputation has fluctuated between being considered a harmful habit and a potential protective factor. The AHA reviewed recent studies focusing on cardiovascular risks and found that moderate coffee consumption, up to 400 milligrams of caffeine daily, is not only harmless but may even lower the risk of heart disease. This amount corresponds roughly to three to five cups of black brewed coffee, each around 240 milliliters. However, this guideline varies depending on the type of coffee consumed. For instance, the European Food Safety Authority (EFSA) estimates that 200 milliliters of filtered coffee contains approximately 90 milligrams of caffeine, while a 60-milliliter espresso holds about 80 milligrams. Similar conclusions were drawn from a 2023 analysis of data from a British health database involving nearly 450,000 individuals. The EFSA also supports these findings, stating that up to 400 milligrams of caffeine per day is generally safe for healthy adults. Nevertheless, recommendations differ for specific groups. Pregnant women are advised to limit their intake to 200 milligrams of caffeine daily, and individuals with pre-existing conditions should consult a healthcare provider before increasing their coffee consumption, as medical history, medications, and individual responses to caffeine can influence safety. Short-term effects of caffeine include increased heart rate and blood pressure, and some people may experience palpitations or anxiety. However, long-term studies suggest that the body adapts to regular caffeine intake, reducing these immediate effects. Dr. Omar Hahad, head of cardiology at the University Medical Center Mainz, notes that many long-term studies are observational in nature, meaning they identify correlations rather than proving cause-and-effect relationships. Despite this limitation, he concludes that coffee appears to offer benefits for heart and vascular health overall. Dr. Gregory Marcus, leader of the authors group behind the AHA statement, emphasizes that the findings should not be interpreted as a one-size-fits-all recommendation. “There is no universal advice that applies to everyone,” he says. “How individuals metabolize coffee varies significantly, so listening to one's body is crucial.” He adds that people who tolerate a single cup well should not feel pressured to consume more. For those experiencing irregular heartbeats or rhythm disturbances after drinking coffee, experts recommend reducing intake and consulting a doctor. According to current U.S. guidelines, atrial fibrillation does not necessarily require avoiding coffee altogether, as typical caffeine levels do not increase the risk of arrhythmias on average. However, there is evidence suggesting that coffee might exacerbate certain types of arrhythmia, prompting caution among individuals with personal sensitivities. Research also indicates that the timing of coffee consumption could play a role in its health benefits. A 2025 study involving over 40,000 adults in the United States found a link between lower overall and cardiovascular mortality rates among those who drank coffee in the morning. Beyond caffeine, scientists highlight the complexity of coffee itself, noting that it contains hundreds of compounds, including secondary plant substances, aromas, roasting products, and oils, that may contribute to its health effects. Dr. Hahad explains that caffeine alone is likely not responsible for all observed benefits, underscoring the need for further investigation into the broader composition of coffee.