Energy Drinks: Study Links Stimulants to Heart Reports in Young Adults
A study of more than 28,000 reports submitted to the U.S. Food and Drug Administration found cardiac arrest appeared about 11 times as often in reports involving caffeine- and stimulant-containing products. About 45% of reported cardiovascular events linked to stimulant products involved adults ages 18 to 34.
Energy drinks and stimulant-containing supplements were linked to more reports of serious heart problems among young adults in a study released by the American Heart Association (AHA), raising questions about products that can contain high levels of caffeine and other stimulants. The analysis reviewed more than 28,000 reports of cardiovascular events submitted to the U.S. Food and Drug Administration (FDA).
Cardiac arrest appeared about 11 times as often in reports involving caffeine- and stimulant-containing products as in reports involving products without those ingredients, the AHA said. Heart attacks appeared about 4.5 times as often, while reports of ventricular arrhythmias or palpitations appeared about four times as often.
The findings come from a retrospective observational analysis and describe reported events, not the risk to every person who consumes the products. About 45% of cardiovascular-event reports associated with stimulant products involved adults ages 18 to 34.
The reviewed reports included cardiac arrest, heart attacks, abnormal heart rhythms, palpitations, rapid heart rate, chest pain and fainting. The analysis also found elevated reports of rapid heart rate, chest pain and fainting among people consuming products with stimulants.
The study included caffeine, methylxanthines, guarana, yerba mate, synephrine, yohimbine and other compounds. These appeared in products including soft drinks, meal replacement shakes, protein bars, smoothies and vitamins.
Colin Kane, a pediatric cardiologist at UT Southwestern Medical Center who was not involved in the study, said the findings build on earlier case reports about possible heart risks from high caffeine intake. “We've known through case reports and anecdotal evidence that caffeine in high amounts can be potentially dangerous to people with underlying heart conditions and even those who have normal hearts,” he said.
Kane also cautioned that the reports cannot show how many people consumed the products without symptoms or experienced symptoms they never reported. That limitation means the analysis does not establish how frequently the products cause heart problems among consumers.
Senior study author Dr. Pamela Benavidez, a cardiothoracic anesthesiologist at Fairfield Medical Center, said some energy drinks contain up to three times more caffeine per fluid ounce than brewed coffee. Some pre-workout supplements have more than 12 times as much, she said.
A 2026 AHA scientific statement says adults can generally consume up to 400 mg of caffeine per day, equivalent to up to five 8-ounce cups of regular black caffeinated coffee. Benavidez said a small serving of some stimulant products can exceed that guidance.
“These can interact with caffeine in ways that are not fully understood, especially in young, healthy people,” Benavidez said of other stimulants found in some products.
