Energy Drink Study Finds Heart Risk, But Don't Blame Caffeine

The American Heart Association has published a new study that warns consuming a large energy drink in a short period of time may jeopardize heart health. The research involved participants as young as 18 who were tasked with consuming a large caffeinated energy drink that contained ingredients commonly found in these beverages, including taurine and B-vitamins.

The results come from a small study that involved 34 healthy adult volunteers ranging in age from 18 to 40. The researchers assigned the participants to drink one of two 'commercially available' energy drinks, though it didn't name which brands were used. The energy drinks were caffeinated and were consumed within 60 minutes.

The participants were only restricted from drinking more than one 16oz bottle in half an hour. A control group was assigned placebo drinks. According to the American Heart Association, the results were concerning: researchers found that participants who drank 32oz of energy drinks in an hour experienced 'statistically significant' blood pressure increases and changes in the electrical properties of the heart.

Four hours after consuming the beverages, the participants were found to have changes in QT interval, which is the measurement of how long it takes the heart's ventricles to prepare to beat. Substantial changes in QT interval can potentially lead to life-threatening arrhythmia, according to the AHA.

Of note, the researchers measured the amount of caffeine in the energy drinks and found that one contained 304mg, the other 320mg. At these doses, the caffeine wouldn't be expected to cause changes in the participants' ECG results. One or more ingredients other than caffeine may be the cause of these changes.

The study's lead author Sachin A Shah explained:

We found an association between consuming energy drinks and changes in QT intervals and blood pressure that cannot be attributed to caffeine. We urgently need to investigate the particular ingredient or combination of ingredients in different types of energy drinks that might explain the findings seen in our clinical trial.

The possible long-term health effects resulting from energy drink consumption remain unclear.