Energy Drinks Linked to Cardiac Events in Young Adults, AHA-Presented Study Finds

A review of 28,345 cardiac-event reports filed with the Food and Drug Administration between 2017 and 2025 has found that caffeine and stimulant products turn up in those reports far more often than they would be expected to, especially among adults aged 18 to 34. The independent research was presented by the American Heart Association.

Of the 28,345 reports, 854 mentioned caffeine or stimulant-containing energy drinks or dietary supplements. Reports that involved those products were about 11 times as likely to include cardiac arrest as reports about products without such ingredients. They were 4.5 times as likely to include heart attacks. The study also found they were four times as likely to include ventricular arrhythmias, which are abnormal rhythms in the heart's lower pumping chambers, and four times as likely to include palpitations. Elevated heart rate was three times as likely, chest pain 2.71 times, and fainting twice as likely. The patterns held in both men and women.

The study's author is Sai Samayamanthula, a fourth-year medical student at the University of Virginia School of Medicine. In a statement, he said the products are marketed as everyday pick-me-ups and sold beside soda and bottled water, so most people assume they carry no real risk. For many healthy people who drink them occasionally, he said, the risk is probably small. Regular users of energy drinks or stimulant supplements, though, can quickly exceed the recommended daily caffeine limit.

That limit, per the AHA, is 400 milligrams a day. The source equates it to five cups of black coffee, about 12 cans of Coca-Cola at 330 milliliters each, or five 250-milliliter cans of watermelon-flavored Red Bull.

The study is explicit about what it cannot show. It does not prove that caffeinated products caused the reported events; it shows how often caffeine appeared in reports made to health officials. Dr. Gregory M. Marcus, chair of the AHA's 2026 scientific statement on caffeine and cardiovascular disease, said more research is needed to determine whether these stimulant products are truly responsible. The AHA says researchers do not fully understand why the link appears in young people. Possible contributors include how often and when they consume caffeine, such as before intense workouts, mixing it with drugs or alcohol, and the chance of undiagnosed heart conditions.

The findings arrive as the market keeps growing. The AHA says caffeinated energy drink sales topped $20 billion in 2024, and have more than doubled over the past decade.

Litigation has already touched the category. Earlier this year, the family of a 17-year-old girl sued Glazer's Beer and Beverage and Glazer's Beer and Beverage of Texas, distributors of the Alani Nu brand, alleging her death came from an enlarged heart caused by drinking large amounts of caffeine. The family's attorney said the distributors were named because they receive, distribute and place the product everywhere, and fail to give warnings. Celsius Inc., which bought Alani Nu in April 2025, told NBC News it was saddened by the loss and takes product safety seriously. It noted that the cans disclose 200 mg of caffeine and say the product is not recommended for children, people sensitive to caffeine, or pregnant or nursing women.

Panera faced similar suits over its Charged Lemonades. It changed the labels, then discontinued the drinks. In October 2024 it reached its first settlement in a wrongful death case, and in July 2025 it settled the rest, including another wrongful death suit and two complaints from customers who said the drink caused cardiac problems despite previously good health. Panera had called two of the wrongful death suits without merit and admitted no wrongdoing.

What the study can and cannot say will shape what follows: researchers are calling for further work to test whether the reporting pattern reflects real causation.