Are Energy Drinks to Blame for Heart Attacks in Young Adults?

Maybe you have one in your hand right now: a tall, cold can that promises to get you through a double shift, a study session or a 6 a.m. workout. Then your feed shows you this: "Young adults are increasingly having cardiac events, and new research shows energy drinks are to blame."

That line opens an Instagram post from @hashem.alghaili, shared around November 8, 2026. The study behind it is real, and the numbers in the post are right. But "to blame" is a bigger claim than the study can make. Here is what the researchers found, why their kind of data can't settle the question, and what is worth knowing about caffeine, especially if you are being treated for cancer.

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The study behind the post

The research comes from a team at the University of Virginia School of Medicine. The study author, Sai Samayamanthula, is a fourth-year medical student there. The American Heart Association (AHA) announced the work on November 2, 2026, ahead of its Scientific Sessions meeting in Chicago (November 6 to 9), where it was shown as abstract MDP0323.

The team went through 28,345 reports sent to the U.S. Food and Drug Administration (FDA) from 2017 to 2025 about possible bad reactions to foods and supplements, in people 13 and older. Of those, 854 named an energy drink or a dietary supplement containing caffeine or other stimulants. The other 27,491 were about products without stimulants, such as soft drinks, meal replacement shakes, protein bars, smoothies and vitamins.

The "stimulant" group was broad. Besides plain caffeine, it included guarana, yerba mate, green tea and coffee extracts, and stronger stimulants such as synephrine, yohimbine, ephedra, DMAA and higenamine. Products were sorted by ingredient, not by brand.

Then the team compared the two piles. In reports about stimulant products, compared with the other reports:

• cardiac arrest (the heart suddenly stopping) showed up about 11 times as often
• heart attack showed up about 4.5 times as often
• dangerous rhythms in the heart's lower chambers, or palpitations, about 4 times as often
• a fast heart rate nearly 3 times, chest pain about 2.7 times and fainting about 2 times as often

About 45% of the heart-related reports in the stimulant group involved adults ages 18 to 34. The pattern looked similar in men and women.

Why a pile of reports can't name a culprit

The FDA's reporting system for foods and supplements works a lot like a complaint box. Anyone can drop in a note: a shopper, a doctor or a company. Makers of dietary supplements must pass along serious reports they get. The FDA's own description of the system is blunt: a report does not mean the product caused the problem, and the data can't be used to tell how often a problem happens or how risky a product is.

Picture a restaurant's complaint box. If notes about the spicy wings mention stomachaches more often than notes about the salad, that is worth looking into. But the box can't tell you how many hundreds of people ate the wings and felt fine. It can't tell you who also had three beers, or who already had a stomach bug. And the people who wrote in are not a fair sample of everyone who ate there.

The FDA reports have the same blind spots. The study authors said it plainly: no one knows how many people used these products with no problem, or how many had heart trouble and never reported it. So "11 times more often" means 11 times more often in the complaint box, not 11 times the risk for a person who drinks one.

That is also why other experts hold back. Gregory Marcus, a cardiologist who chaired the AHA's 2026 statement on caffeine and was not part of the study, said the results raise concerns, but "the study does not prove that caffeine products cause these events, because other factors may have influenced the results." A pediatric cardiologist quoted by Fox News, Colin Kane, put it simply: "We don't know how many people consumed these drinks and didn't report symptoms."

Groups that speak for the industry pushed back too. The Council for Responsible Nutrition, which represents supplement makers, said the study lumps together energy drinks, energy shots and supplements, and does not account for how much or how often people used them.

The researchers offered several reasons the pattern might be strong in young adults: how often they use these products, when they use them (for example, right before hard exercise or mixed with alcohol or drugs), or a heart condition no one had found yet. These are possibilities, not findings.

One more thing to keep in mind: this is an early report. The AHA says meeting abstracts are not peer-reviewed, and their findings are considered preliminary until they are published in full.

Two words the post added

"To blame" claims cause. The study found a pattern in reports, and its own authors say it can't prove cause.

"Increasingly" claims a trend. The study compared two groups of reports. It did not measure whether heart events in young adults are going up over time.

The post's caption does say, further down, that the work is an early abstract based on voluntary reports. But the first line, the one most people read, says something the study does not.

How much caffeine is in that can?

This is where the study's message is most useful. The FDA says that for most adults, 400 milligrams (mg) of caffeine a day, about two to three 12-ounce cups of coffee, is an amount not generally linked to harmful effects. The AHA's 2026 caffeine statement uses the same 400 mg mark.

Here are the FDA's ranges for some common drinks:

So one big can at the high end holds most of a day's 400 mg. Two of them goes past it. According to the AHA, some energy drinks have up to 3 times as much caffeine per ounce as brewed coffee, and some pre-workout supplements have more than 12 times as much.

Too much caffeine can cause a fast or pounding heart, high blood pressure, jitters, trouble sleeping and an upset stomach, the FDA says. Taking in about 1,200 mg quickly can cause seizures.

Samayamanthula's own advice is measured: "For many healthy people, if these products are consumed occasionally, the risk is probably small. However, individuals who consume energy drinks or other stimulant-containing supplements regularly can quickly exceed the recommended daily limit for caffeine."

The verdict

The numbers in the post are right. The idea that energy drinks are "to blame" goes further than the research. What the study does show is a warning sign worth taking seriously: heart problems turned up more often than expected in reports about high-stimulant products, many of them involving young adults. The authors are calling for closer safety tracking, and they want doctors to ask young patients with palpitations, chest pain or fainting whether they use these products.

If you have cancer or had it

This study was not about cancer. But the National Cancer Institute (NCI) says some cancer treatments can affect the heart. Chemotherapy and radiation can cause or worsen high blood pressure, abnormal heart rhythms and heart failure, and some newer treatments, such as certain targeted drugs and immunotherapies, can also affect the heart. Our page on cardio-oncology explains more.

If you are in treatment, or had a treatment that can affect the heart, tell your care team about energy drinks, pre-workout powders and stimulant supplements, the same way you would tell them about medicines. They can help you decide what is safe for you. Our page on coffee during chemotherapy covers when NCI suggests skipping caffeinated drinks.

When to get help

Call 911 if you have signs of a heart attack, such as chest pain or pressure, shortness of breath, or pain in one or both arms, the back, neck or jaw. MedlinePlus says to call "even if you are not sure it is a heart attack." If you faint, or your heart races or pounds after one of these products, get medical help right away.

For more on reading health headlines, see how to evaluate cancer statistics and news headlines.

Sources

• Instagram post (@hashem.alghaili): instagram.com
• American Heart Association news release, "Energy drinks, stimulant products linked to cardiac arrest, heart attack in young adults," November 2, 2026 (abstract MDP0323): newsroom.heart.org; also on EurekAlert
• U.S. Food and Drug Administration, "Spilling the Beans: How Much Caffeine Is Too Much?": fda.gov
• U.S. Food and Drug Administration, "Human Foods Complaint System (HFCS)": fda.gov
• Fox News, "Caffeine and pre-workout supplements tied to heart attack risk, study finds," November 7, 2026: foxnews.com
• Council for Responsible Nutrition, response to the study: crnusa.org
• National Cancer Institute, "Investigating the Cardiac Side Effects of Cancer Treatments," September 21, 2018: cancer.gov
• MedlinePlus, "Heart Attack": medlineplus.gov

How this article was prepared

An AI-assisted editorial system helped prepare this page on November 9, 2026, from the sources listed above. No named medical reviewer has reviewed it unless one is listed. Cancer Explained is published by the National Cancer Information Foundation. It is not medical advice and does not suggest a test or treatment.

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