November 11, 2026, 12:45 pm | Read time: 4 minutes
Germany is a nation of coffee lovers, with 93 percent of adults drinking it regularly. Yet, the fear persists that coffee could trigger heart rhythm disorders like atrial fibrillation. A new large-scale study offers reassurance: Regular coffee consumption significantly reduced the risk of developing the condition in heart-healthy individuals–provided the amount consumed was appropriate. The findings align with previous large-scale studies.
Current Study: The Optimum is 2 to 3 Cups of Coffee Daily
The study authors analyzed data from about 495,000 people who had been observed by researchers for approximately 13 years. Those who regularly drank coffee had a significantly lower risk of developing atrial fibrillation compared to those who did not drink coffee. The protective effect was strongest with two to three cups daily, reducing the risk by 11 percent.
The study by Rui Liang and colleagues was published in late October in the journal “Food & Nutrition Research.”1 It is a prospective cohort study that evaluated data from the UK Biobank. All participants were free of atrial fibrillation at the start. Over the 13-year follow-up period, a total of 37,261 participants developed atrial fibrillation. Daily coffee and tea consumption was self-reported and categorized as follows:
- no coffee
- 0.5–1 cups
- 2–3 cups
- and 4 or more cups per day
The risk of atrial fibrillation was calculated using statistical methods.
Atrial Fibrillation Risk: Even Half a Cup of Coffee Shows Effect
The protective effect of coffee was significant across nearly all consumption levels, making a coincidence almost impossible. Regular coffee drinkers generally had a lower risk of atrial fibrillation than those who did not drink coffee. While half to one cup daily reduced the risk by seven percent, the protective effect for four or more cups was nine percent. The best result was achieved by coffee drinkers with two to three cups a day–an 11 percent reduction.
Also interesting: Drinking coffee late can significantly disrupt sleep
Caffeinated Tea Could Not Keep Up
The researchers also inquired about the participants’ tea consumption. Why? For one, tea is a staple beverage in the UK, where the study was conducted. More importantly, comparing tea allowed researchers to determine whether the observed protective effect of coffee was solely due to caffeine or specific beverage ingredients. It turned out that while the protective effect was generally present with coffee, it was only seen with tea at a consumption level of two to three cups daily. This suggests that compounds in coffee beans likely play a crucial role.
The researchers conclude: The study authors, led by Rui Liang, conclude that daily coffee consumption across various amounts is associated with a significantly reduced risk of new-onset atrial fibrillation. In contrast, tea shows only a modest protective effect. Further research is needed to confirm these observations and understand the reasons behind them.
Study Has a Significant Limitation
It is unknown how much coffee participants actually drank over the years. Researchers only asked participants at the beginning of the study about their coffee consumption. They were then observed for about 13 years without being asked again about their coffee intake. Someone who initially drank two cups daily might have later stopped drinking coffee or consumed significantly more. This was not accounted for in the analysis. In nutritional studies, it is often assumed that coffee consumption is a relatively stable habit in adults over the years.
It is also important to understand that while the study shows coffee drinkers are less likely to develop atrial fibrillation, it suggests–but does not prove–that coffee is the reason.
How the Combination of Coffee and Tea in Moderation Affects Mortality Risk
In These Individuals, Drinking Three to Four Cups of Coffee Daily Slows Biological Aging
Coffee Seems Good for the Heart–Other Studies Show This Too
However, the results of the current study seamlessly connect with what other large-scale epidemiological studies have shown about general cardiovascular health. A large analysis by the European Society of Cardiology in 2021 with nearly 470,000 participants also showed that moderate coffee consumption (0.5 to 3 cups daily) significantly reduced the risk of stroke and cardiovascular disease.2 In another scientifically valuable clinical study with 200 patients, one cup of coffee per day reduced the risk of atrial fibrillation recurrence by 39 percent compared to patients who did not drink coffee.3
Given this broad study base, it is only logical that researchers see moderate coffee consumption as a “reasonable option” for patients with atrial fibrillation after successful treatment.
Conclusion
In Germany, 93 percent of adults regularly drink coffee–an average of 163 liters per person per year.4 Given the estimated 1.5 to 2 million people with atrial fibrillation, studies like this are highly relevant. Research increasingly shows that daily coffee consumption in moderate amounts is not only harmless but can be a simple component of heart health. Studies in recent years on topics such as diabetes, weight management, and longevity have already suggested that coffee is healthier than its reputation suggests.