Abstract Flags Cardiac Reports Tied to Caffeinated Products; CRN Disputes Method

Researchers presenting at the American Heart Association (AHA) Scientific Sessions 2026 reported that caffeine- and stimulant-containing energy drinks and supplements appeared disproportionately in FDA adverse-event reports of cardiac arrest and heart attack, according to an AHA news release.¹ The Council for Responsible Nutrition (CRN) responded that the preliminary analysis cannot establish cause or incidence.²

What Did the Researchers Analyze?

Study author Sai Samayamanthula, a fourth-year medical student at the University of Virginia School of Medicine, and colleagues reviewed 28,345 reports submitted to an FDA safety database from 2017 to 2025. Of those, 854 involved caffeine- or stimulant-containing energy drinks or dietary supplements, while 27,491 involved products without those ingredients. Ingredient categories included caffeine, methylxanthines such as guarana and yerba mate, and sympathomimetics such as synephrine, yohimbine, ephedra, DMAA, and higenamine. Products were grouped by ingredient rather than brand.

AHA noted that energy drink sales exceeded $20 billion in 2024 and that FDA regulates these products as foods or dietary supplements, so they do not undergo premarket safety testing required for medications.

What Did They Find?

Among the caffeine and stimulant products, cardiac arrest appeared in reports roughly 11-fold more often than among products without those ingredients. Heart attack reports were about 4.5 times more likely, and ventricular arrhythmias or palpitations about 4 times. Roughly 45% of the cardiovascular reports involved adults ages 18 to 34. The researchers said the reason for the pattern in young adults is unclear and may reflect usage habits, such as consuming the products before intense exercise or with alcohol, or undiagnosed heart conditions.

The reports were voluntary, so the number of users and unreported events is unknown. AHA also noted that the abstract has not been peer reviewed. Gregory M. Marcus, MD, MAS, who chaired AHA’s 2026 caffeine scientific statement and was not involved in the study, said “the study does not prove that caffeine products cause these events, because other factors may have influenced the results found in this analysis.”

The release cited the statement’s finding that up to 400 mg of caffeine daily is generally safe for most adults. It added that some energy drinks contain up to 3 times more caffeine per fluid ounce than brewed coffee.

How Is CRN Responding?

In a published statement, CRN said the abstract combines energy drinks, concentrated shots, and pill or powder supplements, so it cannot show which category contributed to the reporting signals. The group added that the analysis includes ingredients, such as ephedra, DMAA, and higenamine, that it says cannot legally be marketed in supplements or food, and that exposure was not verified. It also highlighted that the study does not account for amount or frequency of use, adherence to label directions, or concurrent caffeine, alcohol, or medication use.

Andrea Wong, PhD, CRN’s chief science officer, said, “Importantly, the reported 11-fold difference in cardiac arrest reporting does not mean consumers are 11 times more likely to experience cardiac arrest.” CRN said moderate caffeine intake is generally considered safe for most healthy adults and supports continued research and safety monitoring.

What Regulatory Activity Should Manufacturers Watch?

In an Oct. 28 analysis, the law firm Venable reported that lawmakers in New Jersey, Pennsylvania, New York, and Delaware are considering bills that would flag high-caffeine beverages on menus, with proposed thresholds from 80 mg to 250 mg per serving.³ New York’s S9158 would also extend labeling requirements to packaged foods and dietary supplements containing more than 10 mg of caffeine. Venable noted that FDA placed draft caffeine-labeling guidance on its 2026 agenda but that guidance alone cannot set binding national requirements. The firm advised companies to determine total caffeine from all sources, including naturally occurring caffeine and proprietary blends.

References

1. American Heart Association. Energy drinks, stimulant products linked to cardiac arrest, heart attack in young adults. News release. November 2, 2026. Accessed November 5, 2026. https://newsroom.heart.org/news/energy-drinks-stimulant-products-linked-to-cardiac-arrest-heart-attack-in-young-adults
2. Council for Responsible Nutrition. CRN responds to preliminary study on caffeinated products and cardiovascular events. Statement. Accessed November 5, 2026. https://www.crnusa.org/newsroom/crn-responds-preliminary-study-caffeinated-products-and-cardiovascular-events
3. Meyerhoff R, Harrison TA. How much caffeine is “high caffeine”? State bills signal a broader labeling and youth-access debate. Venable LLP. October 28, 2026. Accessed November 5, 2026. https://www.venable.com/insights/publications/2026/10/how-much-caffeine-is-high-caffeine-state-bills