A new analysis presented by the American Heart Association links energy drinks and stimulant-laced supplements to serious cardiovascular events, including cardiac arrest and heart attacks, with young adults making up nearly half of the reported cases.
The research, set to be presented at the AHA Scientific Sessions in Chicago from November 6–9, 2026, reviewed more than 28,000 reports submitted to the FDA involving cardiovascular events such as cardiac arrest, myocardial infarction, ventricular arrhythmias, palpitations, rapid heart rate, chest pain and fainting.
Cardiac arrest showed up roughly 11 times as often in reports involving caffeine- and stimulant-containing products compared with reports that did not involve those ingredients. Heart attacks appeared about 4.5 times as often, and ventricular arrhythmias or palpitations about four times as often, according to the AHA. Elevated heart rate, chest pain and fainting were also more common among that group.
Roughly 45% of the reported cardiovascular events tied to stimulant products involved adults ages 18 to 34.
The stimulants examined included caffeine, methylxanthines, guarana, yerba mate, synephrine, yohimbine and related compounds, found in products ranging from soft drinks and meal-replacement shakes to protein bars, smoothies and vitamins.
An Ohio Researcher’s Warning
The study’s senior author, Dr. Pamela Benavidez, a cardiothoracic anesthesiologist at Fairfield Medical Center in Lancaster, Ohio, said the sheer concentration of caffeine in some of these products is easy to underestimate.
“Some energy drinks have up to three times more caffeine per fluid ounce than brewed coffee, and some pre-workout supplements have more than 12 times as much. This means one small serving can easily surpass the advised daily limit or more,” Benavidez told Fox News Digital.
Benavidez also flagged the added risk from other stimulants frequently blended into these products, such as synephrine, yohimbine and methylhexanamine. “These can interact with caffeine in ways that are not fully understood, especially in young, healthy people,” she said.
According to a 2026 AHA Scientific Statement on caffeine and cardiovascular disease, up to 400 mg of caffeine a day — about five 8-ounce cups of regular black coffee — is generally considered safe for adults.
Outside Experts Weigh In
Colin Kane, M.D., a pediatric cardiologist and service chief at Children’s Health and a professor at UT Southwestern Medical Center who was not involved in the study, said the findings reinforce concerns already raised in individual case reports.
“We’ve known through case reports and anecdotal evidence that caffeine in high amounts can be potentially dangerous to people with underlying heart conditions and even those who have normal hearts,” Kane said.
Kane said people with existing heart conditions — particularly those prone to dangerous rhythms, and older adults with coronary artery disease — need to be especially cautious. He also pointed to a less obvious risk group: “There’s a whole group of people who may have an underlying heart condition that they’re not diagnosed with yet.”
Benavidez advised young people to pay attention to warning signs during or after consuming these products, including palpitations, chest pain or tightness, lightheadedness, fainting, or a racing or irregular heartbeat. “If you notice any of these symptoms, seek medical help right away,” she said. “If you have a known heart condition, a family history of sudden cardiac events, or take medications that are classified as stimulants or can affect your heart rate/rhythm, you should talk to your doctor before using these products at all.”
Limits of the Data
The findings are preliminary and have not yet been published in a peer-reviewed journal. Because the study was observational, it can only show an association, not prove the products caused the cardiac events. Kane noted that researchers don’t know how many people consumed these drinks without reporting symptoms, or whether some people had symptoms and never filed a report. The FDA reports used in the analysis were voluntary and may be incomplete or inconsistently submitted.
Other contributing factors — including alcohol or drug use, strenuous exercise, or undiagnosed heart conditions — could also have played a role in the reported events. “Anytime you’re mixing stimulants and other substances or medications, it can certainly bring up a potential for harm,” Kane said.
Industry Pushback
The American Beverage Association, based in Washington, D.C., defended the safety record of energy drinks in a statement to Fox News Digital: “Energy drinks have been enjoyed by billions of people around the world for more than 30 years and are recognized as safe by government food safety agencies worldwide. The U.S. Food and Drug Administration, Health Canada, the European Food Safety Authority all relied on the highest quality science when they determined that a moderate daily intake of 400 milligrams of caffeine from all sources is safe for adults.” The group added that “energy drinks have less caffeine than coffeehouse coffee and no regulatory agency has found that their other ingredients interact harmfully with caffeine.”
Andrea Wong, chief science officer of the Council for Responsible Nutrition, also questioned how the findings should be interpreted. “Because the analysis does not account for how many consumers actually used these products, whether they were overused or misused, or even the amount of caffeine (or other ingredients) per serving, it cannot determine the incidence of cardiovascular events or quantify the associated risk,” Wong said. “Importantly, the reported 11-fold difference in cardiac arrest reporting does not mean consumers are 11 times more likely to experience cardiac arrest.”
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