Caffeine and heart rhythm: Why coffee didn’t worsen AFib in a new clinical trial
- Adam Austin
- Nov 19, 2025
- 1 min read
Updated: Feb 3
Original story by Kristen Dalli
A randomized clinical trial found that among people with a history of Atrial fibrillation (AFib) or related rhythm issues, drinking at least one cup of caffeinated coffee daily was associated with a significantly lower rate of recurrence.
Participants were randomly assigned either to continue consuming caffeinated coffee (about one cup a day) or to completely abstain from coffee and caffeine for six months following a heart-rhythm resetting procedure.
Results showed recurrence of AFib or atrial flutter in 47% of the coffee group versus 64% in the caffeine-abstinence group — a roughly 39% lower hazard of recurrence for the coffee drinkers.
If you’ve been told to steer clear of coffee because of irregular heartbeats, you may be in for a pleasant surprise.
AFib — where the upper chambers of the heart beat rapidly and unevenly — affects millions and is often managed by lifestyle tweaks, including avoiding stimulants.
But a new study from University of California, San Francisco (UCSF) and the University of Adelaide suggests that one cup of caffeinated coffee a day may not only be safe, but might actually lower the risk of recurrence of these rhythm disturbances.
“Coffee increases physical activity which is known to reduce atrial fibrillation,” researcher Gregory M. Marcus, MD, MAS, said in a news release.
“Caffeine is also a diuretic, which could potentially reduce blood pressure and in turn lessen A-Fib risk. Several other ingredients in coffee also have anti-inflammatory properties that could have positive effects.”
