One Cup of Coffee Daily Cuts AFib Recurrence Risk by 39%, New Study Finds
If you’ve ever been told to cut out caffeine because of heart concerns, you’re not alone. For years, the assumption has been that coffee is risky if you have atrial fibrillation (AFib), the most common heart rhythm disorder worldwide. But a new randomized clinical trial1 is flipping that long-held belief on its head, and offering surprisingly good news for coffee lovers.
Researchers followed 200 adults with persistent AFib for six months and discovered that drinking just one cup of caffeinated coffee a day reduced the risk of AFib recurrence by 39%. Yes, lowered the risk, not increased it.
For the 59 million people across the globe who’ve experienced AFib, these results offer a simple, daily habit that might meaningfully improve outcomes. And for the rest of us? It’s another reminder that coffee’s relationship with heart health might be far more supportive than we once believed.
Coffee for the heart
To test whether caffeine truly fuels abnormal rhythms (or might actually protect against them), researchers enrolled 200 adults with persistent AFib or atrial flutter. All participants were current or recent coffee drinkers and were scheduled for electrical cardioversion, a common procedure used to restore normal heart rhythm.
Then, participants were randomly assigned to one of two groups for six months.
- Coffee group: encouraged to drink at least one cup of caffeinated coffee every day
- Abstinence Group: asked to avoid all caffeine—coffee, decaf, tea, energy drinks, everything
Because participants had a similar coffee habit at baseline (about seven cups per week), the researchers could clearly isolate the effect of adding or removing caffeine.
The power of a cup of joe
By the end of the six-month trial, the difference was striking.
- 47% of people in the coffee group experienced AFib recurrence
- 64% of people in the abstinence group experienced recurrence
That translates to a 39% lower hazard of recurrence for the daily coffee drinkers, a statistically significant and clinically meaningful reduction. Importantly, the coffee group didn’t experience more adverse events, which helps counter the idea that caffeine inherently destabilizes heart rhythm.
Why might coffee help? Researchers point to several potential mechanisms:
- Lower blood pressure over time, particularly in habitual drinkers
- Anti-inflammatory compounds naturally present in coffee
- More daily movement, as past trials show coffee drinkers often log ~1,000 more steps
- Favorable effects on cardiac electrical pathways, which may help keep rhythm steadier
While the exact mechanism isn’t fully defined, the overall signal is clear: habitual, moderate coffee intake may actually support a more stable heart rhythm.
The takeaway
This new clinical trial challenges decades of conventional wisdom and opens the door to a more nuanced understanding of caffeine and heart rhythm health. Findings like these remind us that small, sustainable habits can sometimes offer real cardiovascular benefits.
So if you look forward to your morning mug, this study suggests it may be doing more good than you realized.