Key Points:
- An atrial fibrillation study found that daily coffee may reduce AF risk.
- Coffee drinkers had a 39% lower chance of recurrent AF.
- Moderate coffee intake is safe and may protect heart health.
A new international atrial fibrillation study has found that drinking coffee daily may help reduce the risk of atrial fibrillation (AF), an irregular heartbeat that can lead to stroke and heart failure. The findings challenge long-standing medical advice that caffeine worsens heart rhythm disorders.
Researchers from the University of Adelaide and the University of California, San Francisco (UCSF) led the world’s first randomized trial to test coffee’s effect on AF. The study involved 200 adults across Australia, the United States, and Canada who had a history of the condition.
Over six months, half of the participants drank at least one cup of coffee or an espresso shot each day, while the other half avoided all coffee and caffeine. Participants were continuously monitored, and any AF events were confirmed by electrocardiograms and clinical assessments.
First global trial on coffee and AF
“The results were astounding,” said lead author Professor Christopher X. Wong from the University of Adelaide and Royal Adelaide Hospital. “We found that those who drank coffee experienced a significant reduction in AF compared to those who avoided caffeine.”
Wong added that the findings contradict traditional medical guidance. “Doctors have always recommended patients with AF limit coffee intake, but this trial suggests that coffee is not only safe but may be protective,” he said.
AF occurs when the upper chambers of the heart (atria) beat irregularly, disrupting normal blood flow. It can cause dizziness, fatigue, and palpitations, and increase the risk of stroke, heart failure, and death. More than 10 million U.S. adults live with the condition, and its prevalence rises with age.
Researchers report surprising heart benefits
The DECAF (Does Eliminating Coffee Avoid Fibrillation) trial showed that coffee consumption was associated with a 39% lower risk of recurrent AF events compared to abstinence. The researchers suggested several possible explanations for this effect.
“Coffee increases physical activity, which is known to reduce AF,” said senior author Professor Gregory Marcus from UCSF’s Division of Cardiology. “Caffeine also acts as a diuretic, potentially lowering blood pressure and decreasing AF risk. In addition, certain compounds in coffee have anti-inflammatory properties that may benefit heart health.”
The U.S. National Coffee Association estimates that about two-thirds of adults drink at least one cup of coffee daily. Previous research has explored its potential links to improved brain function, slower aging, and better cardiovascular health.
Results challenge long-held medical advice
“The number of people with AF is increasing, particularly among older adults,” Marcus said. “Our findings offer greater clarity on the role of caffeinated coffee in managing the condition and should help guide future medical recommendations.”
Although AF has often been linked to caffeine, the study suggests that this association may need revision. The researchers noted that lifestyle factors such as diet, obesity, sleep apnea, diabetes, and family history remain major contributors to AF.
While the atrial fibrillation study does not claim coffee as a cure for AF, it indicates that moderate consumption may offer protective effects without increasing risk.
“Based on these results, coffee-drinking patients with AF can safely continue enjoying their coffee,” Wong said. “It may even be worth investigating whether non-coffee drinkers with AF should consider adding it to their routine.”
The full atrial fibrillation study was published in The Journal of the American Medical Association.
