Coffee May Protect Against Common Irregular Heartbeat

A new study suggests that a daily cup of coffee may lower the odds of atrial fibrillation recurrence, offering reassurance to the millions living with the common heart rhythm disorder. Researchers followed 200 adults from Australia, Canada, and the US with a history of A-fib, averaging 70 years old, over the course of six months. Participants were split into two groups: one mostly avoided coffee, the other drank at least one cup daily. Data from ECGs and heart monitors showed 47% of coffee drinkers experienced a recurrence of A-fib or atrial flutter, compared to 64% in the no-coffee group, per NBC News. Coffee drinkers also went longer before having a recurrence.

Dr. Gregory Marcus of UC San Francisco, a co-author of the study presented at the American Heart Association conference and published in JAMA, noted that many patients had previously stopped drinking coffee based on physician advice, though there's been no consensus on whether caffeine triggers episodes. The study is among the first to suggest a cause-and-effect relationship between coffee and reduced A-fib recurrence, rather than just an association. This could be due to the anti-inflammatory effects of coffee. On the other hand, "caffeine is also a diuretic, which could potentially reduce blood pressure and in turn lessen A-Fib risk," Marcus says in a release.

However, some limitations remain. The trial did not account for other caffeinated drinks, exercise, or diet, and about a third of the no-coffee group admitted to drinking at least one cup during the study. The protective effect seemed linked to moderate coffee consumption, and it's unclear if more than one cup would help or harm. Dr. Johanna Contreras, a cardiologist not involved in the research, emphasized that reactions to caffeine vary and that moderation is key. She added that coffee appears "perfectly safe" for those with treated or resolved A-fib, but the findings may not apply to people with unmanaged episodes, as caffeine could worsen symptoms in those cases, per NBC.