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The American Heart Association energy drink study is raising fresh questions about the cardiovascular risks of highly caffeinated beverages and stimulant supplements. A preliminary analysis of more than 28,000 reports submitted to a U.S. Food and Drug Administration safety database found that products containing caffeine or other stimulants appeared disproportionately often in reports involving serious heart problems.
The findings, presented as an abstract at the American Heart Associationās Scientific Sessions 2026, focused particularly on adults ages 18 to 34. That group is not typically viewed as being at high risk for heart attacks or cardiac arrest, making the reported pattern especially notable.
American Heart Association Energy Drink Study Reveals Alarming Signals
Researchers reviewed 28,345 adverse-event reports covering the years 2017 through 2025. Of those, 854 reports mentioned caffeinated energy drinks or stimulant-containing dietary supplements, while 27,491 involved products without caffeine or other stimulants.
The analysis did not compare specific brands. Instead, researchers grouped products according to ingredients, including caffeine, methylxanthines such as guarana and yerba mate, and sympathomimetics such as synephrine, yohimbine and higenamine.
According to the study, cardiac arrest was reported about 11 times more often in connection with caffeine- and stimulant-containing products than with products lacking those ingredients. Reports involving energy drinks and supplements were also about 4.5 times more likely to include heart attacks and four times more likely to include ventricular arrhythmias or heart palpitations.
Heart Attack, Palpitations and Fainting Reports Increased
The reported associations extended beyond the most serious outcomes. Elevated heart rate appeared nearly three times more often, chest pain was reported 2.71 times more often, and fainting occurred about twice as often in reports involving stimulant products.
- About 45% of reports connected to cardiovascular events involved adults ages 18 to 34.
- Similar reporting patterns were observed among men and women.
- Ventricular arrhythmias, or abnormal rhythms in the heartās lower chambers, were reported more frequently.
- The analysis included reports involving people ages 13 and older.
Study author Sai Samayamanthula, a fourth-year medical student at the University of Virginia School of Medicine, said regular consumers can quickly exceed recommended caffeine limits. Products are often marketed as convenient energy boosters and displayed alongside soft drinks, which may lead consumers to underestimate their potential risks.
Why Young Adults May Face Greater Risk
Researchers said they do not yet know why the association appeared especially strong among younger adults. Consumption habits may play a role, including taking stimulant products before intense exercise, combining them with alcohol or drugs, or consuming multiple products within a short period.
An undiagnosed heart condition could also contribute. Symptoms such as racing heart, chest pain, dizziness or fainting should not be dismissed, particularly after consuming a high-caffeine beverage or pre-workout supplement.
Some energy drinks contain as much as three times more caffeine per fluid ounce than brewed coffee. Certain pre-workout supplements contain more than 12 times as much caffeine per fluid ounce. The American Heart Association says up to 400 milligrams of caffeine daily is generally safe for most adults, although individual sensitivity varies.
Important Limits of the Preliminary Research
Experts emphasized that the American Heart Association energy drink study does not prove these products caused cardiac arrest or heart attacks. The data came from voluntary safety reports, meaning researchers cannot determine how many people consumed stimulant products without experiencing problems or how many cardiovascular events went unreported.
Gregory M. Marcus, M.D., M.A.S., FAHA, who was not involved in the analysis, said the results are concerning but observational. Other factors may have influenced the findings, and more research is needed to determine whether high-dose caffeine products directly trigger heart-related events.
The abstract has not been peer-reviewed and should be considered preliminary until the research is published as a complete manuscript in a scientific journal. Still, researchers called for more systematic safety monitoring and encouraged health care professionals to ask younger patients about energy drink and supplement use when they report palpitations, chest pain or fainting.
What Consumers Should Know Now
Consumers should check caffeine amounts on labels and consider all sources consumed throughout the day, including coffee, soda, tea, energy drinks and supplements. Extra caution may be appropriate before intense physical activity or when combining stimulants with alcohol or other substances.
Anyone experiencing severe chest pain, difficulty breathing, fainting or signs of cardiac arrest should seek emergency medical help immediately. People with recurring palpitations or unusual symptoms should discuss their caffeine and supplement habits with a health care professional.
Are energy drinks proven to cause heart attacks?
No. The study found an association in voluntary safety reports, but it cannot prove that energy drinks or stimulant supplements directly caused heart attacks or cardiac arrest.
How much caffeine is generally considered safe?
The American Heart Association reports that up to 400 milligrams of caffeine per day is generally safe for most adults. Individual tolerance, medications and health conditions can change that risk.
Who appeared most often in the reports?
Adults ages 18 to 34 accounted for about 45% of reports involving cardiovascular events linked to caffeine- and stimulant-containing products.
What symptoms should prompt medical attention?
Chest pain, fainting, severe palpitations, shortness of breath and an unusually fast or irregular heartbeat should be taken seriously and evaluated promptly.
