The surprise heart benefit of coffee that can protect people against irregular heartbeats

Drinking just a cup of coffee a day could be enough to help protect against a common heart condition that affects more than 10 million Americans, a new study has found.

Atrial fibrillation, also known as A-Fib, is a disorder that can result in sudden heart death, heart failure and strokes. The number of people living with A-Fib has also been increasing in recent years, as more obesity levels and the age of the population rise.

Doctors typically recommend that people with heart issues avoid caffeine to prevent raising heart rate and blood pressure, but a new peer-reviewed study found that consuming the beverage daily actually reduced the risk for A-Fib episodes by 39 percent.

“Coffee increases physical activity which is known to reduce atrial fibrillation,” Dr. Gregory Marcus, an electrophysiologist at the University of California at San Francisco Health, said in a statement.

“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.”

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Marcus and his co-authors studied the health of 200 coffee-drinking adults with A-Fib or a related heart condition called “atrial flutter” over the course of six months in the U.S., Canada and Australia.

After receiving electrical cardioversion – an electrical shock that shifts the heart into a normal rhythm – half of the participants were told to drink at least one cup of coffee a day, while the other half were told to cut out all caffeine.

The researchers found that the risk of recurrent A-Fib was significantly lower among those drinking caffeine compared to the group that went cold turkey, at 47 percent to 64 percent, respectively.

“The results were astounding,” Dr. Christopher Wong, the first author of the research, said.

Although, the authors noted that those results may have partially been because people drinking coffee were consuming fewer unhealthy beverages, and said some people may still find that caffeine and coffee is a trigger for worsened symptoms.

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“It is reasonable for health care professionals to let their A-Fib patients consider experimenting with naturally caffeinated substances that they may enjoy, such as caffeinated tea and coffee. However, some people may still find that caffeine or caffeinated coffee triggers or worsens their AFib,” Marcus said.

The findings build on previous research suggesting the risk of atrial fibrillation lessened over time in nearly 19,000 male doctors who drank one to three cups of coffee a day.

The research was presented Sunday at the American Heart Association’s Scientific Sessions 2025 meeting.