WEDNESDAY, Sept. 2 (HealthCare tips) -- People who drink lots of coffee but who don't follow a Mediterranean-style diet are more likely to have atrial fibrillation, a new study shows.

Italian researchers asked patients who'd been newly diagnosed with the common heart arrhythmia to supply information about their dietary habits, including caffeine consumption. Their diets were compared with those of people without atrial fibrillation.

The findings were existing this week at the European Society of Cardiology annual meeting in Barcelona.

Daily coffee intake was divided into four categories: low (one cup/day), medium (two to three cups/day), heavy (more than three cups/day) and none, the study writers noted in a society news release.

Patients were also ranked according to their adherence to the Mediterranean diet, which is rich in whole grains, olive oil, fruits and vegetables and includes little red meat.

People with atrial fibrillation were less probable to follow the Mediterranean diet than those without the heart condition, according to the study. Those with atrial fibrillation also consumed more red meat and full-fat dairy products.

It was also noted that patients with atrial fibrillation consumed more of their total dietary antioxidants from coffee compared to other food sources, such as fruits, vegetables and wine, the researchers pointed out in the news release.

The heaviest coffee drinkers were also more likely to have atrial fibrillation than those who drank less, the study found. In atrial fibrillation, the heart's two upper chambers quiver instead of beating frequently, leading to heart palpitations, shortness of breath, fatigue and an increase in the risk of stroke.

"Our study suggests that high intake of coffee increases the risk of arrhythmias in people without known cardiac disease," study author Dr. Anna Vittoria Mattioli, of the University of Modena in Italy, said in the news release.