Most people with abnormal heart rhythms (atrial fibrillation or ventricular arrhythmias) can safely consume coffee and other caffeinated beverages in moderation, despite the common concern that caffeine can trigger arrhythmias, according to a 2018 research review in JACC: Clinical Electrophysiology.
After evaluating 19 major studies, the researchers concluded that “although there is no clearly defined threshold for caffeine harm, a regular intake of up to 300 milligrams a day appears to be safe and may even be protective against heart rhythm disorders.” That's the amount of caffeine in about three cups of coffee.
However, they stated that there may be individual differences in reactions to caffeine, and that if someone does find that arrhythmias occur after caffeine consumption, then “avoidance is sensible.”
This article first appeared in the UC Berkeley Wellness Letter.
Also see Flu Shot Reduces A-Fib Risk.