Coffee and an irregular heartbeat: what a trial found
NHS advice for people with atrial fibrillation lists caffeine among the triggers to avoid.
Among coffee drinkers with persistent atrial fibrillation, those assigned to keep drinking coffee were less likely to have the condition return within six months than those assigned to give it up, a trial in JAMA has found.
The NHS’s atrial fibrillation page, last reviewed in January 2025, lists among things people can do themselves to help with symptoms: “avoid triggers such as caffeine, spicy food, stress, dehydration and lack of sleep”.
The trial, published in January, enrolled 200 adults at five hospitals in the US, Canada and Australia. All had persistent atrial fibrillation, or atrial flutter with a history of it, and were due to have electrical cardioversion. All drank coffee, or had within the previous five years. Half were encouraged to drink at least one cup of caffeinated coffee a day; the other half to abstain from coffee and other caffeine-containing products for six months.
The primary end point was clinically detected recurrence of atrial fibrillation or atrial flutter. It came back in 47% of the coffee group and 64% of the group that gave up coffee. The authors reported no significant difference in adverse events.
The patients had an average age of 69, and 71% were men. The trial was open-label, meaning the patients were not blinded to their group. The paper describes the result as an association: allocation to coffee “was associated with less recurrence”.
In its advice on lowering blood pressure, the NHS’s high blood pressure page lists drinking too much caffeine among the things not to do, adding that “drinks high in caffeine include coffee, tea and cola”. It does not say how much counts as too much.
A 2012 review of 15 studies, published in the Journal of Hypertension, found that low-quality evidence did not show any statistically significant effect of regular coffee drinking on blood pressure or the risk of high blood pressure. Its authors wrote that no recommendation could be made for or against coffee consumption as it relates to blood pressure.
A 2026 analysis of 38 studies with more than 2.8 million participants, in BMC Cardiovascular Disorders, found no significant associations between coffee and heart failure or coronary heart disease when comparing the highest and lowest consumption categories. It reported a significant positive association between higher coffee consumption and heart attack. The authors wrote that higher intake “might increase the risk” of heart attack but can also offer protective effects against stroke and cardiac arrhythmias. They noted that intake was self-reported across the studies.
The NHS atrial fibrillation page says to see a GP for palpitations that keep happening or are getting worse. It says to call 999 for a fast or irregular heartbeat together with symptoms such as chest pain, shortness of breath or fainting.
