Energy drinks and stimulant-containing supplements have been linked to the risk of serious heart problems, including cardiac arrest and heart attacks, particularly among young adults.
That’s according to new research released by the American Heart Association, which will be presented at the AHA Scientific Sessions in Chicago, November 6–9, 2026.
A retrospective observational analysis looked at more than 28,000 reports submitted to the FDA of cardiovascular events, including cardiac arrest, myocardial infarction (heart attack), ventricular arrhythmias (abnormal rhythms), palpitations, tachycardia (rapid heart rate), chest pain and syncope (fainting).
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Cardiac arrest appeared in reports involving caffeine- and stimulant-containing products about 11 times as often as in reports involving products without those ingredients.
Heart attacks were reported about 4.5 times as often, while ventricular arrhythmias (abnormal heart rhythms) or palpitations were reported about four times as often, according to the AHA.
Elevated heart rate, chest pain and fainting were also increased among the group consuming those substances.
Approximately 45% of reported cardiovascular events associated with stimulant products involved adults ages 18 to 34.
The stimulants included in the study were caffeine, methylxanthines, guarana, yerba mate, synephrine, yohimbine and other compounds. They were consumed in products such as soft drinks, meal replacement shakes, protein bars, smoothies and vitamins.
Caffeine and heart risks
Colin Kane, M.D., pediatric cardiologist and service chief at Children’s Health and professor at UT Southwestern Medical Center, said the findings build on earlier case reports about potential heart risks from high caffeine intake.
“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, who was not involved in the study, told Fox News Digital.
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It is generally safe for adults to consume up to 400 mg of caffeine per day, which equates to up to five 8-ounce cups of regular black caffeinated coffee, according to a 2026 American Heart Association Scientific Statement on caffeine and cardiovascular disease.
“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,” senior study author Dr. Pamela Benavidez, a cardiothoracic anesthesiologist at Fairfield Medical Center in Lancaster, Ohio, told Fox News Digital.
“This means one small serving can easily surpass the advised daily limit or more.”
Benavidez also warned that these products often include other stimulants like synephrine, yohimbine and methylhexanamine.
“These can interact with caffeine in ways that are not fully understood, especially in young, healthy people,” she said.
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The researchers recommend that young people carefully monitor their consumption of caffeine and watch for heart-related symptoms, such as palpitations, chest pain or tightness, lightheadedness, fainting, or a racing or irregular heartbeat during or after use of these products.
“If you notice any of these symptoms, seek medical help right away,” Benavidez advised. “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.”
Kane identified people with underlying heart conditions, particularly those with potentially dangerous heart rhythms and older adults with coronary artery disease, as groups needing particular awareness.
“And there’s a whole group of people who may have an underlying heart condition that they’re not diagnosed with yet,” he added.
Study limitations
The findings are preliminary and have not yet been published as a full peer-reviewed manuscript.
As the study was observational, it could only show an association and could not prove that the products caused the cardiac events.
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“We don’t know how many people consumed these drinks and didn’t report symptoms or those who maybe had symptoms and didn’t report them,” Kane said.
Also, as the FDA reports were voluntary, they may contain incomplete, inconsistent or selectively submitted data.
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It is possible that other factors, such as alcohol or drug use, strenuous exercise and undiagnosed heart conditions, may have contributed to the cardiovascular events.
“Anytime you’re mixing stimulants and other substances or medications, it can certainly bring up a potential for harm,” Kane said.
Industry response
The American Beverage Association, based in Washington, D.C., sent the below statement to Fox News Digital in response to the study.
“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.”
“Energy drinks have less caffeine than coffeehouse coffee and no regulatory agency has found that their other ingredients interact harmfully with caffeine,” the statement concluded.
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Andrea Wong, chief science officer of the Council for Responsible Nutrition in Washington, D.C., also reacted to the study’s findings.
“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,” she told Fox News Digital.
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“Importantly, the reported 11-fold difference in cardiac arrest reporting does not mean consumers are 11 times more likely to experience cardiac arrest.”
