CATEGORY: FOODS & NUTRIENTS
People diagnosed with atrial fibrillation are routinely told to cut out coffee. Put to a randomized test, giving it up did not protect their heart rhythm. Six months after a procedure reset their heartbeat to normal, the irregular rhythm had come back in 47% of adults assigned to keep drinking coffee and 64% of those assigned to quit caffeine entirely, a 39% lower risk among the coffee drinkers.1 Atrial fibrillation is an irregular, often racing heartbeat.
Conventional Wisdom That Had Never Been Tested
The authors put their question bluntly. Caffeinated coffee is widely believed to provoke heart-rhythm disturbances, and patients with atrial fibrillation have long been told to cut back or stop. Yet no randomized trial had ever checked the advice in these patients. DECAF, published in JAMA, is the first, and the answer ran opposite to the assumption it examined. A daily coffee habit went with fewer episodes rather than more, and the difference was statistically solid.1
One Cup a Day or None at All for Six Months
Cardiologists at five hospitals in the United States, Canada and Australia enrolled 200 adults, average age 69, about seven in ten of them men. All drank coffee at the time or had within the past five years, and all had persistent atrial fibrillation scheduled for electrical cardioversion. That procedure is a brief, controlled electrical pulse delivered under sedation to reset the heart to a normal beat, something like rebooting a stuttering computer. A random draw, not a preference, put half the patients on at least one cup of caffeinated coffee a day and asked the other half to avoid coffee and all caffeine. The two groups separated as intended: about seven cups a week on one side, essentially none on the other. For six months, doctors tracked in clinical follow-up whose atrial fibrillation or its close cousin, atrial flutter, returned.1
Forty-Seven Against Sixty-Four, and No Extra Trouble
By six months the rhythm problem had returned in 47 of every 100 coffee drinkers and 64 of every 100 abstainers.1 Counting only atrial fibrillation and setting flutter aside barely moved the result. Safety told the same story. Emergency-room visits (13 versus 16) and hospitalizations (23 versus 21) were similar between the groups, and nobody in either group died. For a beverage patients are routinely taught to fear, the trial picked up no sign that a daily cup was doing rhythm-related harm.
What 200 People Over Six Months Can Say
The boundaries here are honest ones. Two hundred people and six months speak to relapse over that window, not to decades of heart health. Nobody was blinded, since a cup of coffee cannot be disguised. Everyone enrolled already drank coffee or recently had, so the trial says little about someone who has never liked the stuff. And the coffee group averaged about a cup a day, which leaves heavier drinking untested. Observational research sits underneath the trial and leans the same way: two Swiss studies followed 3,835 people already living with atrial fibrillation for a median of 4.7 years, and among daily coffee drinkers the rate of stroke, heart attack, cardiovascular death or hospitalization for heart failure ran 23% below the rate in those who did not drink it daily, with the lowest rates of all among people having two to three cups a day.2 Those studies watched people’s own habits rather than assigning them, so they establish association rather than cause. What DECAF establishes is narrower and firmer. Among coffee-drinking adults treated for this condition, quitting coffee was not the arm with fewer relapses.
Key Takeaways
- In the first randomized trial of coffee in atrial fibrillation, patients assigned a daily cup after a rhythm-resetting procedure carried a 39% lower risk that the irregular rhythm would return over six months: 47 relapses per 100 people against 64 per 100 among those told to avoid all caffeine.
- Emergency visits and hospitalizations came out similar in both groups, with no deaths in either.
- The trial covered coffee drinkers averaging about one cup a day for six months. It does not address heavier intake, lifelong abstainers, or longer-term outcomes.
- Observational data from 3,835 patients followed for nearly five years link daily coffee to fewer major heart events, an association rather than proof of cause.
References
- Wong CX, Cheung CC, Montenegro G, et al. Caffeinated Coffee Consumption or Abstinence to Reduce Atrial Fibrillation: The DECAF Randomized Clinical Trial. JAMA. 2026;335(4):317–325. link
- Iten V, Herber E, Coslovsky M, et al. Coffee consumption and adverse cardiovascular events in patients with atrial fibrillation. BMC Medicine. 2024;22(1):593. link