Energy drinks can affect the heart—and not in a good way. At times, these concoctions have been linked to emergency room visits and deaths.

Shah SA, Szeto AH, Farewell R, et al. Impact of High Volume Energy Drink Consumption on Electrocardiographic and Blood Pressure Parameters: A Randomized Trial. Journal of the American Heart Association. 2019;8(11).

Studies show that consuming energy drinks can lead to changes in blood pressure and heart rate and that they may increase the risks of developing severe heart issues such as stroke.  

 

Stroke prevalence has been high in the US—it’s the nation’s leading cause of death—with case numbers increasing over the last few years. According to the Centers for Disease Control and Prevention (CDC), stroke prevalence among adults aged 18–64 years increased by 7.8% between reports from 2011–2013 and 2020–2022.

Imoisili OE, Chung A, Tong X, et al. Prevalence of Stroke — Behavioral Risk Factor Surveillance System, United States, 2011–2022. MMWR Mob Mortal Wkly Rep. 2024;73:449–455.

 

 

The exact connections between energy drink consumption and stroke risks are understudied. To stay ahead of the unknown, researchers and health organizations advise consumers to limit their energy drink consumption. They also encourage doctors to have conversations with patients about the known and potential risks of these beverages, and to encourage healthy limits.

Heart and Stroke Foundation of Canada. Atrial fibrillation.

 

 

Research on energy drinks and the heart

 

While research on energy drinks—and stroke, specifically—is limited, a handful of studies evaluate energy drinks’ impacts on the heart.

 

Energy drink study

 

A 2019 study in Journal of the American Heart Association (AHA) is the largest study to evaluate the impact of energy drinks on healthy individuals.

Shah SA, Szeto AH, Farewell R, et al. Impact of High Volume Energy Drink Consumption on Electrocardiographic and Blood Pressure Parameters: A Randomized Trial. Journal of the American Heart Association. 2019;8(11).

The study included 34 healthy participants between the ages of 18 and 40. Participants were asked to drink 32 ounces of an energy drink or placebo within one hour over the course of 3 days. Using an electrocardiogram, the researchers charted the heart’s QTc interval—along with other metrics—to assess any changes. They concluded that the energy drinks impacted the heart by significantly prolonging the QTc interval and raising blood pressure.

 

The risk of stroke in people with prolonged QTc interval is almost three times the risk than those with normal QTc interval.

Soliman EZ, Howard G, Cushman M, et al. Prolongation of QTc and Risk of Stroke: The REGARDS (REasons for Geographic and Racial Differences in Stroke) Study. Journal of the American College of Cardiology. 2012;59(16):1460–1467.

Additionally, for people with acute ischemic, research has found prolonged QTc intervals to be predictors of early mortality.

Wu J, Nizhamuding D, Liu P, et al. QT interval prolongation in patients with acute ischemic stroke: a report in northwest China. The Journal of International Medical Research. 2019;47(12):5986–5995.

 

 

High blood pressure can increase a person’s risk for stroke by leading to blood clots in the brain, damaging vessels in the brain, and increasing risks of bleeding in the brain.

Stroke Association. High blood pressure.

 

 

Study on Redbull and the heart 

 

A 2023 study found that people who consumed the energy drink Red Bull experienced decreases in the velocities of their carotid and middle cerebral arteries as well as a decrease in cardiac output and heart rate.

Costa R, Rocha C, Santos H. Cardiovascular and Cerebrovascular Response to RedBull® Energy Drink Intake in Young Adults. The Anatolian Journal of Cardiology. 2023;27(1):19–25.

Some of these changes can also be associated with stroke.

 

 

Studies on energy drinks and Afib

 

Other research has noted cases in which teenagers developed atrial fibrillation (AFib) after consuming unknown quantities of energy drinks.

Di Rocco JR, During A, Morelli PJ, et al. Atrial fibrillation in healthy adolescents after highly caffeinated beverage consumption: two case reports. Journal of Medical Case Reports. 2011;5(1).

People with AFib have a three to five times greater risk for stroke.

Heart and Stroke Foundation of Canada. Atrial fibrillation.

They may also have multiple strokes, including silent strokes.

National Institute of Neurological Disorders and Stroke. Atrial Fibrillation and Stroke. January 23, 2023.

 

 

“Given the possibility of cardiac arrhythmias and other untoward effects developing from caffeine use and abuse, further clinical trials reviewing the physiological effects and addictive potential for children and adolescents should be pursued, given the paucity of caffeine literature in this age group,” the researchers wrote. “Perhaps future studies could evaluate serum caffeine levels in pediatric patients who present with arrhythmias and concurrent caffeine consumption; this may be a useful measure to quantify into a risk model, should this correlation continue to be observed.”

 

Recommended limits on energy drinks and caffeine

 

Health organizations in the US have yet to set a recommended limit for caffeine intake for consumers and drink manufacturers. For now, the Food and Drug Administration (FDA) says that up to 400 milligrams of caffeine a day—or about four or five cups of coffee—is generally safe for adults.

FDA. Spilling the Beans: How much Caffeine is Too Much? September 7, 2023.

For children between the ages of 12 and 18, the American Academy of Child and Adolescent Psychiatry (AACAP) recommends sticking to 100 milligrams or fewer (about two cans of cola) daily. For children under 12, the AACAP says, caffeine is not recommended at all.

 

When it comes to energy drinks, health organizations are even more cautious. The American Academy of Pediatrics (AAP) discourages children and adolescents from consuming energy drinks altogether. Additionally, the CDC asks parents, staff, teachers, coaches, and community members to educate younger people on the risks of energy drinks and to model healthy behaviors such as avoiding these substances.

Centers for Disease Control and Prevention. The Buzz on Energy Drinks. August 15, 2022.