UCSF Cardiology scientists report no connection between arrhythmia and coffee consumption.
In the biggest research of its kind, a study by UC San Francisco has found no evidence that moderate coffee consumption can cause cardiac arrhythmia.
In fact, each additional daily intake of a cup of coffee among thousand of individuals was associated with a 3 percent lower risk of any arrhythmia occurring, including premature ventricular contractions, atrial fibrillation, or different heart conditions, the scientists report. The research covered a four-year follow-up.
The article was issued on July 19, 2021, in JAMA Internal Medicine.
“For most people, coffee is the prime source of caffeine, and it has a status for causing or provoking arrhythmias,” said senior and corresponding author Gregory Marcus, MD, professor of medicine in the Division of Cardiology at UCSF.
“But we did not any evidence that caffeine intake drives to a higher risk of arrhythmias,” said Marcus, who specializes in the handling of arrhythmias. “Our population-based research gives reassurance that general prohibition on caffeine to lessen arrhythmia risk are likely unwarranted.”
While some experts recommend dodging caffeinated products to reduce the risk for arrhythmia, this connection has not been consistently explained — indeed, coffee consumption may have anti-inflammatory interests and is connected with reduced risks of some diseases including diabetes, cancer, and Parkinson’s syndrome.
In the latest research, UCSF researchers examined whether regular coffee consumption was connected with a risk of arrhythmia and whether hereditary variants that influence caffeine metabolism could transform that association. Their investigation was carried via the community-based UK Biobank, planned research of participants in England’s National Health Services.
Some 386,258 coffee drinkers took part in the coffee study, with an average mean age of 56 years; slightly more than half were female. It was a unique sample size for this kind of analysis.
Furthermore, in a traditional analysis examining self-reported coffee intake as a predictor of likely arrhythmias, the investigators used a method called “Mendelian Randomization,” leveraging hereditary data to understand causal relationships. As those with the hereditary variants connected with faster caffeine metabolism drank more coffee, this study provided a way to examine the caffeine-arrhythmia relationship in a way that did not rely on participant self-report and should have been immune to much of the confounding inherent to most observational studies.
With a mean four-year follow-up, data were arranged for demographic characteristics, lifestyle, and health habits.
Ultimately, about 4 percent of the sample developed an arrhythmia. No sign of an increased risk of arrhythmias was seen among those genetically predisposed to metabolize caffeine adversely. The scientists stated that higher amounts of coffee were associated with a 3 percent decreased risk of developing an arrhythmia.
The authors noted limitations including the self-reporting quality of the research, and that specific data on the kind of coffee — such as espresso or not — was unavailable.
“Only a randomized clinical analysis can definitively show clear effects of coffee or caffeine intake,” said Marcus. “But our research observed no evidence that drinking caffeinated beverages raised the risk of arrhythmia. Coffee’s antioxidant and anti-inflammatory characteristics may play a role, and some attributes of caffeine could be protective against some arrhythmias.”
Journal Reference: “Coffee Consumption and Incident TachyarrhythmiasReported Behavior, Mendelian Randomization, and Their Interactions” by Eun-Jeong Kim, Ph.D.; Francesca Delling, MD; Thomas J. Hoffmann, Ph.D.; Gregory Nah, MA; Eric Vittinghoff, MD and Gregory M. Marcus, MD, MAS, 19 July 2021, JAMA Internal Medicine.
Co-authors are Eun-Jeong Kim, MD; Gregory Nah, MA; Thomas J. Hoffmann, Ph.D.; Eric Vittinghoff, Ph.D.; and Francesca Delling, MD, all of UCSF.