Category: Diet

How caffeine affects the heart.

A staple of morning routines everywhere, coffee is the most popular drink worldwide! Coffee, as well as black tea, energy drinks, and chocolate, are all common sources of caffeine in our modern diets. While caffeine helps get our energy flowing, it also can have negative impacts on the heart when consumed in excess – especially in those diagnosed with atrial fibrillation (AFib). Dr. Nazeri explains how caffeine affects the heart in this latest article.


How Does Caffeine Work?

Caffeine is a stimulant for the brain. After having a caffeinated drink, it is normal to have more energy and feel more awake. No wonder coffee is so popular!

In addition to affecting the brain, caffeine can impact other parts of the body as well. Everyone has a different tolerance level to caffeine, but everyone can feel the negative symptoms of having too much. Common symptoms of high levels of caffeine consumption include increased heart rate, sweating, feelings of stress, shakiness, and headaches.


Caffeine and the Heart

Because of its shape, caffeine is able to interact with the cells in the body to cause a release of stress hormones. High levels of stress hormone can cause the heart to beat faster, skip a beat, or even change the rhythm. Furthermore, individuals with heart conditions like AFib are at an increased risk of developing more severe heart problems from consuming a lot of caffeine – but how much caffeine is too much?


How Much Caffeine is Too Much?

The average cup of black coffee has up to 180 mg of caffeine – and a cup of black tea has around 50 mg. Energy drinks are meant to have high amounts of caffeine and can contain over 250 mg per can. But how much caffeine is safe?
According to the FDA, consuming up to 400 mg of caffeine per day (about 4-5 cups of coffee) is still considered “safe.” Although, it is advisable for individuals with heart conditions to speak with their health provider about safe caffeine levels for their health.


Safety Considerations for Caffeine and AFib
  • Check for added caffeine in processed foods and drinks. Energy drinks, workout supplements, and even some desserts can have added caffeine – so be sure to check the food label before eating.
  • Limit caffeine intake throughout the day. Cutting back on the number of morning cups of coffee and tea can help reduce the risk of ingesting too much caffeine throughout the day.
  • Have a caffeine cut-off time. Consuming caffeine late into the day can harm your heart and sleep health, thus, setting a cut-off time for drinking caffeine is a way to help reduce consumption.
  • Finally, consult with a cardiologist for a deeper understanding of how caffeine affects the heart. People diagnosed with AFib or any cardiac arrhythmia should consult with a cardiologist about their caffeine consumption.


early detection of Atrial fibrillation specialist Dr, Nazeri

Dr. Nazeri and AFib Treatment

Dr. Nazeri is a cardiac electrophysiologist at Mobitz Heart and Rhythm Center. For more information about caffeine and AFib, please consult with Dr. Nazeri or visit us at


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