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Energy drinks and stimulant supplements show up far more often than other products in American safety reports of cardiac arrest and heart attacks, especially among young adults. That is the headline finding of a new analysis of federal adverse-event records, presented ahead of the American Heart Association's Scientific Sessions 2026. But the study's authors are equally clear about what it does not show — and the distinction matters.
According to reports from Medical Xpress and MedicineNet, drawing on the association's November 2 news release, researchers at the University of Virginia School of Medicine examined 28,345 reports submitted to the US Food and Drug Administration's safety database between 2017 and 2025, covering people aged 13 and older. Of those, 854 involved energy drinks or dietary supplements containing caffeine or other stimulants.
The numbers
Compared with reports about products without caffeine or stimulants, reports about stimulant-containing products mentioned cardiac arrest about 11 times as often, heart attacks about 4.5 times as often, and ventricular arrhythmias or heart palpitations about four times as often. Strikingly, adults aged 18 to 34 accounted for roughly 45 percent of the reports linking stimulant products to cardiovascular events — a group usually considered at low baseline risk for such emergencies. Men and women showed similar patterns, the reports said.
The lead author is Sai Samayamanthula, a fourth-year medical student at the University of Virginia. The researchers suggested several possible reasons young adults stood out, including how often they use these products, using them before intense exercise, mixing them with alcohol or drugs, and undiagnosed heart conditions. The findings are due to be presented at the association's Scientific Sessions in Chicago, running November 6 to 9.
What this study cannot prove
This is where careful reading matters. The study counts voluntary safety reports. It does not follow people over time, it cannot say how common heart events are among all energy-drink consumers, and it cannot prove that any product caused any event. Other factors may have influenced the results, and people who suffer a frightening symptom are more likely to file a report in the first place. The work is also preliminary: it is a conference abstract, not yet published as a full paper in a peer-reviewed journal, and conference abstracts are explicitly flagged as preliminary until that happens.
None of that makes the signal meaningless. A safety database exists precisely to spot patterns that deserve closer study, and an elevenfold difference in reporting frequency, concentrated in young adults, is a pattern worth investigating properly. But it is not the same as proof that one can of an energy drink causes a heart attack, and headlines that drop the word "reported" mislead readers.
How much caffeine is considered safe?
For context, the American Heart Association's 2026 scientific statement on caffeine and cardiovascular disease says consuming up to 400 milligrams of caffeine per day — roughly five 8-ounce cups of regular black coffee — is generally safe for most adults. Energy drinks and stimulant supplements vary widely, and some pack far more caffeine than a cup of coffee, sometimes combined with other stimulants whose combined effects are less well studied. Anyone with a heart condition, or who notices palpitations, chest pain, or dizziness, should speak to a clinician rather than relying on general guidance.
The honest summary of this research is therefore two-sided. There is a real, striking safety signal in the FDA's own reporting system, centred on young adults, and it deserves proper follow-up studies. And there is not yet proof of cause and effect — only an association in self-reported data, presented as a preliminary abstract. Both halves belong in the same story. For another recent health finding where early numbers needed careful reading, see A Child Has Died of Measles in New York for the First Time in 30 Years.
This article is general information only and is not medical advice.