Energy Drinks Linked to Heart Events in Young Adults, Study Finds
A review of more than 28,000 FDA adverse-event reports found cardiac arrest reported about 11 times more often in connection with caffeinated energy drinks and stimulant supplements. The pattern was strongest in adults ages 18 to 34. The researchers say the design shows an association, not proof of cause.
Energy drinks and stimulant supplements showed up far more often than other products in U.S. reports of serious heart problems, according to new research released Monday. The pattern was strongest in adults ages 18 to 34, a group not usually considered at high risk for heart trouble.
The research comes from the University of Virginia. The team reviewed 28,345 reports sent to a Food and Drug Administration safety database between 2017 and 2025. Of those, 854 mentioned caffeine- or stimulant-containing energy drinks or dietary supplements. The rest covered products without caffeine or stimulants, such as soft drinks, protein bars and vitamins.
The findings are preliminary. They are set to be presented this week at the American Heart Association’s Scientific Sessions 2026 in Chicago, which runs November 6 to 9. The work is a research abstract, not yet a peer-reviewed paper.
What the numbers showed
Cardiac arrest was reported about 11 times more often in connection with caffeine- and stimulant-containing products than with products without those ingredients. Reports involving energy drinks and supplements were about 4.5 times more likely to include heart attacks, and four times more likely to include ventricular arrhythmias or heart palpitations.
The same pattern held for other complaints. Elevated heart rate showed up nearly three times more often. Chest pain showed up 2.71 times more often. Fainting showed up about twice as often.
About 45 percent of the reports linking caffeine- and stimulant-containing products to cardiovascular events involved adults ages 18 to 34. The pattern held for both men and women.
“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,” said study author Sai Samayamanthula, a fourth-year medical student at the University of Virginia School of Medicine. “For many healthy people, if these products are consumed occasionally, the risk is probably small. 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.”
What it does not prove
The study’s authors are blunt about the limits. The reports were filed voluntarily by consumers, doctors and manufacturers. The design can only show associations. It cannot prove that any product caused any heart event.
It is also unknown how many people consumed these products without any heart event, or how many had heart events and never filed a report. The researchers grouped products by ingredient, not by brand, so the findings point to types of products rather than any single brand. The ingredients counted included caffeine, methylxanthines such as guarana and yerba mate, and sympathomimetics such as synephrine, yohimbine, ephedra and DMAA.
“This study raises concerns that products with very high amounts of caffeine may be harmful to the cardiovascular system,” said Dr. Gregory M. Marcus, chair of the American Heart Association’s 2026 scientific statement on caffeine and cardiovascular disease. Marcus was not involved in the study. “Although there are biological reasons why that connection could be possible, the study does not prove that caffeine products cause these events, because other factors may have influenced the results found in this analysis. More research is needed to understand whether these stimulant products are truly responsible for the reported heart-related events.”
The researchers do not fully understand why the association was so frequent among young adults. It may reflect how often young adults consume these products, when or how they consume them — for example, before intense exercise or mixed with alcohol or drugs — or whether some had an undiagnosed heart condition.
Why the products are different
Sales of caffeinated energy drinks have more than doubled over the past decade, reaching over $20 billion in 2024. Some energy drinks contain as much as three times more caffeine per fluid ounce than brewed coffee. Some pre-workout supplements contain more than 12 times as much per fluid ounce.
The FDA regulates energy drinks and stimulant supplements as foods or dietary supplements, not as medications. They do not go through the same premarket safety testing required for medications.
According to the American Heart Association’s 2026 scientific statement, consuming up to 400 milligrams of caffeine a day — the equivalent of up to five 8-ounce cups of regular black coffee — is generally safe for most adults. Regular users of energy drinks and stimulant supplements can pass that limit quickly.
Samayamanthula said the findings support more systematic safety monitoring of caffeine- and stimulant-containing products. He also said health care professionals should ask younger patients who report palpitations, chest pain or fainting whether they recently or regularly consume these products.
