Energy drinks linked to cardiac arrest in young adults, study finds

Caffeinated energy drinks are available in grocery and convenience stores across the United States and while flavors like watermelon, Shirley Temple and apple sound enticing, a new study may make young adults think twice before taking a sip.

In a review of more than 28,000 adverse-event reports to the Food and Drug Administration over eight years (2017-2025), independent research presented by the American Heart Association (AHA) found that caffeinated drinks and supplements are "disproportionately" linked to reports of serious cardiovascular events, such as cardiac arrest and heart attacks, especially in young adults ages 18 to 34.

“These products are marketed as everyday pick-me-ups and sold next to soda and bottled water, so most people assume they carry no real risk,” Sai Samayamanthula, the study's author and a fourth-year medical student at the University of Virginia School of Medicine, said in a statement.

While occasional consumption may not pose a risk, individuals who take caffeinated supplements or consume energy drinks consistently could exceed the recommended daily limit for caffeine, thus putting their cardiovascular health at risk, according to Samayamanthula.

The study emphasizes that it does not prove that caffeinated drinks caused the reported cardiac events, but it shows how often caffeine was mentioned in reports of these events to health officials.

"More research is needed to understand whether these stimulant products are truly responsible for the reported heart-related events,” Dr. Gregory M. Marcus, chair of the 2026 American Heart Association scientific statement on caffeine and cardiovascular disease, said.

What is the recommended daily caffeine limit?

The AHA recommends a daily caffeine limit of 400 mg. This is equivalent to five cups of black caffeinated coffee, about 12 330 ml cans of Coca-Cola or five 250 ml cans of watermelon-flavored Red Bull energy drinks.

While drinking a can may not cause harm, people should keep a close eye on their consumption, researchers said.

“For many healthy people, if these products are consumed occasionally, the risk is probably small," Samayamanthula said. "However, individuals who consume energy drinks or other stimulant-containing supplements regularly can quickly exceed the recommended daily limit for caffeine, so it’s important for people to know that there may be a risk of cardiovascular harm with these products.”

The study comes as energy drinks continue to grow in popularity. In 2024, sales of caffeinated energy drinks reached over $20 billion, according to the AHA. Sales have more than doubled in the past decade.

Study finds that caffeine was connected to cardiac arrest reports

Researchers analyzed 28,345 reports of cardiac events that occurred between 2017 and 2025. Of those, 854 mentioned caffeine or stimulant-containing energy drinks or dietary supplements. The study found that cardiac arrest was reported about 11 times more often in connection with caffeine- and stimulant-containing products versus products without these ingredients.

Additionally, reports involving energy drinks or supplements were 4.5 times more likely to include heart attacks, as well as the following:

• 4 times as likely to include ventricular arrhythmias, which are an abnormal rhythm in the lower pumping chambers of the heart
• 4 times as likely to include heart palpitations
• 3 times as likely to include elevated heart rate
• 2.71 times as likely to include chest pain
• 2 times as likely to include fainting

The patterns were observed in both men and women.

Why is caffeine often associated with cardiac events in young people?

The pattern of cardiac events could be more prevalent among young adults because of the following factors:

• How often they consume caffeine
• When the caffeine is consumed, like before intense workouts or strenuous activities
• Mixing caffeine with drugs or alcohol
• Potentially living with undiagnosed heart conditions

However, researchers do not fully know why caffeine is linked to cardiac events among young people, according to the AHA.

Earlier this year, Glazer’s Beer and Beverage and Glazer’s Beer and Beverage of Texas, the distributors of Alani Nu, another energy drink brand, were sued by the family of a 17-year-old girl who alleged her death was due to an enlarged heart caused by drinking large amounts of caffeine.

The family's attorney said it was suing the distributors because they were "the ones that receive it, distribute it and put it all over the place, and they also fail to give any warnings."

In a statement to NBC News, Celsius Inc., which bought Alani Nu in April 2025, said it was saddened by the loss and that it takes “product safety seriously and believes consumers should have clear information about what they are drinking.”

“Alani Nu energy drinks disclose 200mg of caffeine on the can, and the label states the product is not recommended for children, people sensitive to caffeine, pregnant women, or women who are nursing,” the statement said

Panera also faced multiple lawsuits regarding its Charged Lemonades. Panera initially changed the labels on the beverages before ultimately discontinuing them.

In October 2024, Panera reached its first settlement in a wrongful death lawsuit that stemmed from the discontinued drink. In July 2025, Panera settled the remaining lawsuits, which included another wrongful death suit and two legal complaints that alleged the drink led to cardiac problems in two customers who were previously healthy, NBC News and People reported.

Panera previously said that two of the wrongful death lawsuits were "without merit" and did not admit to any wrongdoing, according to USA TODAY's previous reporting.

Contributing: Mary Walrath-Holdridge, USA TODAY

Julia Gomez is a Trending reporter for USA TODAY and covers space phenomena, scientific studies and natural disasters. Connect with her on LinkedIn, X, Instagram, and TikTok: @juliamariegz, or email her at [email protected].