For years, people with heart rhythm problems were told to skip their morning cup of coffee. But new research suggests that advice may need a rethink.
A randomized clinical trial led by the University of California–San Francisco and the University of Adelaide found that drinking one cup of caffeinated coffee a day lowered the risk of atrial fibrillation (A-Fib) recurrence by 39%. A-Fib is a common heart rhythm disorder that affects more than 10 million adults in the U.S. and increases the risk of stroke and heart failure.
“Coffee increases physical activity which is known to reduce atrial fibrillation,” said senior author Dr. Gregory Marcus, a cardiologist and electrophysiologist at UCSF Health. He added that caffeine’s mild diuretic effect and coffee’s anti-inflammatory compounds could also play a role.
In the study, cheekily named DECAF (Does Eliminating Coffee Avoid Fibrillation?) and published in the Journal of the American Medical Association, 200 adults with A-Fib or atrial flutter were randomly assigned to either drink at least one cup of coffee or espresso per day or to avoid caffeine entirely for six months. Those who drank coffee had a significantly lower risk of recurrent A-Fib episodes.
“The results were astounding,” said first author Dr. Christopher Wong of UCSF and the University of Adelaide. “Doctors have always recommended that patients with problematic A-Fib minimize their coffee intake, but this trial suggests that coffee is not only safe but likely to be protective.”
While the findings don’t mean everyone should start upping their caffeine intake, they do offer reassurance for people with heart concerns who already enjoy a daily cup. The study adds to growing evidence that coffee, once viewed with suspicion, can have heart-protective and anti-inflammatory benefits when consumed in moderation.
The research was funded by the National Institutes of Health, including the National Heart, Lung and Blood Institute.