Could caffeine be good for your heart?

Studies suggest regular coffee use protects patients from atrial fibrillation.

April 16, 2018, 6:16 PM

How do you take your caffeine? Caffeine is a stimulant that has been linked to improving how your brain functions. No wonder it is one of the most widely used drugs on the planet. The most common forms of caffeinated beverages include coffee, tea and energy drinks. New research in the Journal of the American College of Cardiology suggests that caffeine is not harmful to the heart, as it has previously been suggested, and may actually be good for it.

Caffeine works by adding more energy to the inside of your cells. Because caffeine is known to make the heart beat faster, many people believe that it can be damaging to the heart’s electrical system. In fact, greater than 80 percent of doctors in the U.S. recommend against caffeine consumption in patients with known abnormal heart rhythms. Many feel the faster heart rate makes your heart more vulnerable to entry into life-threatening rhythms.

On the other hand, caffeine has also been described as an antioxidant. Antioxidants neutralize the negative waste products of your cells’ day-to-day activities and are believed to preserve the long-term health of your cells and tissues. Some scientists believe that caffeine protects the longevity of the heart muscle itself.

Heart doctors do not have great evidence that caffeine causes abnormal heart rhythms. The current recommendations against caffeine are conservative and mostly based on assumptions of how the body works. A new article in the Journal of the American College of Cardiology compiles the data from multiple studies to add scientific data to the debate on caffeine.

On to the results: Multiple studies associate regular coffee drinkers with lower amounts of new-onset atrial fibrillation, commonly known as “a. fib.” Atrial fibrillation is a very common, irregular heart rhythm that increases your risk of stroke. Approximately 9 percent of Americans older than 65 years old have this abnormal rhythm, according to the U.S. Centers for Disease Control and Prevention. Treatment typically includes medications to control your heart rate and potentially blood thinners.

Researchers in this article discuss other types of abnormal rhythms including supraventricular tachycardia (SVT) and ventricular fibrillation (“v. fib”). There were no studies that found an association between caffeine and these rhythms, even in patients who already had sick hearts from heart attacks or heart failure.

While this information may be exciting to our “low fat, half sugar, extra hot” regulars, it is very important to note that some patients with atrial fibrillation have a negative relationship with caffeine. In 25 percent of people who already have the diagnosis of atrial fibrillation, caffeine can actually a trigger an episode of the abnormal rhythm. As always, it’s important to consult your doctor before making any changes.

So here’s the good news.

The authors do not think caffeine causes most abnormal heart rhythms. In fact, they suggest that regular coffee use actually protects patients from atrial fibrillation. Based on data in some animal trials, however, they do recommend a maximum of 300 mg of caffeine per day. This is the equivalent of about three cups of coffee.

If coffee or tea is your drug of choice, you are in luck. If it’s an energy drink, not so much. While coffee and tea seem to be fairly safe, the research suggests that most energy drinks are slightly more risky. Unfortunately for some of our readers, multiple studies recommend against energy drink consumption. Researchers suggest that these drinks may cause life-threatening rhythms and even blood clots. On top of high amounts of caffeine, they often have other ingredients like guarana, sugar and ginseng. These additives seem to amplify the body’s response to the stimulant, causing more harmful side effects including abnormal heart rhythms.

Laura Shopp, MD, a third-year pediatrics resident affiliated with Indiana University, works in the ABC News Medical Unit.