Could that energy drink buzz be risky for your heart? Here’s what new research says
PolitiFact · · g4887398
One too many caffeinated beverages can make your heart feel like it’s working overtime. And new study findings linking energy drinks to cardiac arrests might have had the same effect.
The research, which hasn’t been published or peer-reviewed yet, was presented Nov. 7 at the American Heart Association’s global Scientific Sessions conference in Chicago and led by Sai Samayamanthula, a fourth-year medical student at the University of Virginia.
It leaned on data from more than 28,000 adverse events from food, dietary supplements and cosmetics voluntarily reported to the Food and Drug Administration from 2017 through most of 2025. About 850 of the reports mentioned caffeine- or stimulant-containing energy drinks or dietary supplements.
Cardiac arrest was reported about 11 times more often in connection with such caffeinated products compared with noncaffeinated items. Reports involving these caffeinated drinks and supplements were nearly five times more likely to include heart attacks and four times more likely to include ventricular arrhythmias or heart palpitations.
About 45 percent of the reports linking these products to cardiovascular events involved people ages 18 to 34.
“These findings raise an important safety concern that requires further investigation, particularly for young adults who may not consider themselves at risk for heart problems,” said Northwestern University cardiologist Dr. Rahul Aggarwal.
But the study has limitations.
First, it doesn’t prove these drinks caused heart problems — it mainly highlights a link that should be researched more. We don’t know how many people consumed these drinks with no issue, or had a reaction but didn’t report it to the FDA.
We also don’t know how much caffeine each person consumed, whether they had underlying health issues or pre-existing heart conditions, or whether they consumed the products alongside other substances like drugs and alcohol.
“It does not contain dose, ingredient-level breakdown beyond the product name, or timing between consumption and the event,” Samayamanthula, the study’s lead author, told us.
A 2025 review of existing research looked at 37 studies and found energy drinks caused significant acute cardiovascular effects including increased heart rate, elevated blood pressure, and risky changes in heart rhythm.
These changes alone may just represent a ramping up of the body’s nervous system, and may not necessarily be clinically relevant, said Dr. Gregory Marcus, a cardiologist at the University of California, San Francisco. “Rigorous research investigating the true cardiovascular effects of these is sorely needed.”
However, changes in heart rhythm may pose a greater risk to people who already have heart arrhythmias, or are taking medications that affect the heart. It’s best to talk with your doctor about whether these drinks are a smart choice.
Most of the research we have is on the acute effects of high doses of caffeine in a short period.
“The effects of chronic energy drink consumption on the cardiovascular system needs urgent research,” said Sachin Shah, a cardiovascular pharmacologist. “Currently, we just don’t know the risks. There could be none, but this needs exploration as energy drinks consumption is relatively common.”
Existing research shows that moderate caffeine consumption through coffee and tea may have heart benefits . But Marcus said that doesn’t necessarily mean caffeinated energy drinks have the same health perks.
There are a few factors that may put younger people at higher risk of suffering adverse effects from energy drinks. They may be more likely to consume these drinks excessively — staying up late studying or trying to focus at work after a late night. Young users also may be unaware of the dosage, and be more likely to have an undiagnosed heart issue that they don’t know is affected by caffeine.
Lastly, young people may be more likely to consume energy drinks alongside alcohol or other drugs that could lead to more dangerous interactions.
It’s important to be aware of how much caffeine is in whatever you’re drinking. “ There are significantly higher concentrations of caffeine in most energy drinks than there are in naturally occurring sources of caffeine such as coffee or tea,” said Dr. Brian Downey, a cardiologist at Tufts Medicine.
Here are a few standard caffeine doses :
Among energy drinks, doses can vary widely from product to product. An 8-ounce can of Red Bull has 80 milligrams of caffeine, but C4 Ultimate Energy has 300 milligrams. They can also include added stimulant ingredients like guarana and yerba mate .
According to the American Heart Association, consuming less than 400 milligrams of caffeine a day is safe for most adults, but with doses that high in a single drink, consumers can hit that threshold quickly.
And it matters when you drink it. “I frequently see these drinks being consumed at the gym immediately prior to exercise,” Downey said. Electrolyte changes and increased heart rate from exercise combined with high doses of caffeine “may put patients at higher risk of heart attack and cardiac arrest.”
Finally, each person’s body may react differently.
“Different people metabolize caffeine at remarkably different speeds,” Marcus said, “so the same dose consumed by two different people may result in wildly different caffeine levels in their bloodstreams.”