In FDA reports, cardiac arrest was more often associated with stimulant products

• In FDA reports, cardiac arrest was mentioned in connection with stimulant-containing products 11 times more often than with products without them
• An analysis of reports does not prove that drinks or supplements caused medical events
• Researchers call for systematic monitoring and further research

What reports of adverse events revealed

A preliminary study found a notable difference in federal adverse event reports: products containing caffeine and other stimulants appeared in reports of cardiac arrest, heart attacks, and other heart problems significantly more often than products without these ingredients. Specifically, cardiac arrest was mentioned in reports involving stimulant-containing products 11 times more often. This refers to the frequency of mentions in the database, not a calculated risk for each consumer.

The study was presented at the American Heart Association’s Scientific Sessions 2026. The authors examined the FDA’s federal database of reports of suspected adverse reactions to foods and supplements. They compared products containing caffeine and other stimulants with products that did not contain these substances. The control group included, among other things, soft drinks, smoothies, vitamins, protein bars, and meal replacements.

The analysis included reports about people aged 13 and older submitted from 2017 to 2025. Among the notable findings was the frequent presence of young adults in reports of problems associated with caffeinated products: a substantial share involved people aged 18–34. However, the database describes reported suspicions, not confirmed diagnoses obtained by following a predefined group of consumers.

Why the results cannot be considered proof of causation

The key limitation is that this analysis does not establish whether an energy drink or supplement caused a particular cardiac event. The reports show how often these conditions appeared in reports involving different products, and on their own do not answer how likely an event is for someone who uses them. Therefore, the figures cannot be applied directly to an individual’s risk or taken as proof that caffeine or other stimulants were the cause.

The study materials separately explain the scale of this distinction: an 11-fold rate of reports of cardiac arrest and a 4.5-fold rate of reports of heart attacks do not mean that energy drink consumers are respectively 11 or 4.5 times more likely to experience these events. These ratios apply to reports submitted to the FDA. The data do not show how often complications occur among all people who use these drinks and supplements.

The authors believe that the signal they detected nevertheless warrants attention and more systematic safety monitoring of products containing caffeine and stimulants. Gregory Marcus, chair of the American Heart Association’s scientific statement on caffeine and cardiovascular disease, also noted that the findings raise concerns but do not prove a causal relationship. The available study description does not offer a definitive explanation for why these events featured so often in the reports.

Caffeine, young consumers, and regulation

The results come amid rapid market growth: sales of energy drinks more than doubled over the past decade, topping $20 billion in 2024. However, according to the source material, scientists still have limited information about the effects of energy drinks and stimulant supplements on the cardiovascular system. The popularity of these products, therefore, does not mean their long-term effects have been studied as thoroughly.

Caffeine content can vary widely from one product to another. The article notes that some energy drinks contain up to three times as much caffeine per fluid ounce as brewed coffee, while certain pre-workout supplements have concentrations more than 12 times higher than coffee. So the product category alone does not tell you the dose: to assess your intake, it is important to consider the specific product and its ingredients.

A 2026 scientific statement from the American Heart Association says that most adults can generally consume up to 400 milligrams of caffeine per day without significant safety concerns. The source compares this amount to about five eight-ounce cups of black coffee. This is a general guideline for adults, not a claim that any beverage or supplement is safe: their concentrations vary considerably.

What questions remain for doctors and researchers

Another question concerns regulation in the United States. The FDA classifies energy drinks and stimulant-containing supplements as food products or dietary supplements, rather than drugs. As a result, they do not undergo the same mandatory safety reviews as medicines before they reach the market. This distinction does not prove that every product is dangerous, but it explains why researchers are calling for more systematic collection of information about possible adverse reactions.

The particularly high proportion of reports involving young adults has not yet been explained. Researchers suggest that young people may be more likely to use energy drinks and stimulant supplements, leading these products to be mentioned more often when medical incidents are reviewed. Patterns of use may also play a role, including taking them before intense physical activity or combining them with alcohol or drugs. The publication describes these possibilities as hypotheses, not established causes.

The authors also suggest that some people may have previously undiagnosed heart conditions that increase their susceptibility to complications, but the analysis provides no evidence confirming this possibility. Researchers recommend that medical professionals ask young patients experiencing palpitations, chest pain, or fainting about recent or regular use of these products. Further research will need to determine which factors actually explain the pattern in the reports and whether particular products are associated with it.

Source: ScienceDaily