Proponents and opponents of caffeine have long been weighing in on its health effects. Caffeine-lovers will be happy to know that one common caffeine criticism may no longer be on the table.
A new study found that, contrary to popular belief, regular caffeine intake may not lead to extra heartbeats. Extra heartbeats can, in rare cases, lead to heart- or stroke-related morbidity and mortality.
“Clinical recommendations advising against the regular consumption of caffeinated products to prevent disturbances of the heart’s cardiac rhythm should be reconsidered, as we may unnecessarily be discouraging consumption of items like chocolate,coffee and tea that might actually have cardiovascular benefits,” said senior study author Gregory Marcus, MD, MAS, in a press release.
Dr. Marcus, a University of California San Francisco cardiologist and director of clinical research in the UCSF Division of Cardiology, added, “Given our recent work demonstrating that extra heartbeats can be dangerous, this finding is especially relevant.”
The extra heartbeats in question include excessive premature atrial contractions (PACs), which can cause atrial fibrillation, stroke and death. Dr. Marcus and team also looked at excessive premature ventricular contractions (PVCs), which can cause an increased risk of heart failure, coronary artery disease and death. Past studies linked these irregularities to caffeine intake, but they did not use PACs and PVCs as a primary outcome and were performed several decades ago.
However, the American College of Cardiology/American Heart Association guidelines for PVC management continue to state that patients with a history of premature extra heartbeats should eliminate caffeine, nicotine and alcohol from their diet.
Meanwhile, a growing body of evidence suggests that caffeine products like coffee, tea and chocolate might actually benefit the heart. The result of these conflicting ideas is uncertainty about whether to advise patients to consume caffeine products.
For their study, Dr. Marcus and colleagues looked at 1,388 patients from the National Heart, Lung, and Blood Institute Cardiovascular Health Study database, omitting those with persistent extra heartbeats. Patients were given 24-hour heart monitoring and a survey on the frequency of their coffee, chocolate and tea intake.
Of the 1,388 study patients, 61 percent (840) consumed more than one caffeinated item daily.
Dr. Marcus and colleagues found no major differences in the number of PACs or PVCs per hour tied specifically to coffee, tea or chocolate intake. And more frequent consumption of these items did not appear to result in extra heartbeats.
“This was the first community-based sample to look at the impact of caffeine on extra heartbeats, as previous studies looked at people with known arrhythmias,” said lead study author Shalini Dixit, BA, in a press release.
Dixit, a fourth-year medical student at UCSF, added, “Whether acute consumption of these caffeinated products affects extra heartbeats requires further study.”
This study was published Jan. 26 in the Journal of the American Heart Association. It was funded in part by the National Institutes of Health (NIH). Dr. Marcus received research support from the NIH, Patient Centered Outcomes Research Institute, SentreHeart, Medtronic and Pfizer. He was also a consultant for and held equity in InCarda.