Sound Science: Caffeine Consumption and Heart Health

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Java enthusiasts rejoice! While you may have been skipping out on that third mug of coffee for fear of having heart palpitations, the latest research actually shows no connection between caffeine consumption and arrhythmia.

In this study published last year in the Journal of the American Heart Association, scientists did not find any link between caffeine intake and premature cardiac contractions, or extra beats that disrupt your heart’s normal rhythm. These premature contractions can be further categorized as atrial (PAC) or ventricular (PVC). The same research group had previously determined a relationship between PACs/PVCs and increased risk of atrial fibrillation, heart failure, and death.

Study Methods:

In the investigation, 1416 members of the Cardiovascular Health Study (CHS) were randomly recruited from the original pool of nearly 6000 subjects. Participants indicated the frequency with which they consumed certain items by arranging a series of cards depicting common foods and beverages, including coffee, tea, and chocolate. Over 60% of all subjects reported daily consumption of a caffeinated food or beverage. The electrical activity of each participant’s heart was then tracked for 24 hours via a portable electrocardiogram (EKG) monitor. Data analysis revealed nothing that suggested caffeine could cause increased incidence of PACs/PVCs. Even when researchers accounted for additional lifestyle factors that are known to affect the frequency of these occurrences, they did not find any meaningful connection. The rate of premature contractions essentially stayed the same across all groups, no matter how often each consumed caffeinated products.

Study Strengths and Limitations:

The study is unique in that it is the largest to date that examines dietary habits in relation to PAC/PVC activity utilizing EKG monitoring. Furthermore, the methods used to capture participants’ eating and drinking patterns, specifically the use of food frequency questionnaires, had been validated in earlier studies against previously established, similar approaches.

However, it is equally important to recognize the limitations of the study in addition to its strengths. The most obvious drawback is the use of self-report data, which is subject to a number of factors that might skew participant responses (including poor memory and other biases), to determine average caffeine consumption. Additionally, the food-sort approach used in the study did not account for what study participants consumed directly before or during the monitoring period, which may have affected the EKG results. Lastly, researchers were unable to calculate total caffeine intake, instead relying on self-reported frequency of caffeinated product consumption.

Final Thoughts:

We should all know the effects of what we’re putting into our bodies, and caffeine is no exception. An astonishing 85% of Americans reported consuming caffeine on a daily basis in a separate study. We want to make the best possible recommendations, and shying away from caffeine based on unsubstantiated reports may do more harm than good. Refer to our previous Sound Science blog post that explores the health benefits of caffeine, which include combating inflammation and even reducing the risk of some chronic diseases!

So if you feel your heart skipping a beat, just know that it’s not that cup of Joe you had this morning.