Energy drinks tied to prolonged QT interval

Many American’s love to partake in a Monster drink or Red Bull to reduce fatigue. I myself have been known to have a couple of them every once in a while. It makes sense that a stimulant-laced drink like these energy drinks may be increasing your risk for increased blood pressure in plus. These slow killers are sure to leave an impact but they are over time. The question is if these drinks can cause instant harm.

Hemodynamic changes, such as blood pressure and pulse, after intake of energy drinks in humans, is not debated. We know that the stimulants in energy drinks could synergistically induce harmful effects on blood pressure and pulse, but there are few studies to support the concern for arrhythmias.

A new study from the American Heart Association from 2019​[1]​ confirms prior results​[2]​ and shows that there is a concern for arrhythmias and especially those involving a prolonged QT interval such as Torsades de pointes. This arrhythmia is especially concerning because it can result in sudden cardiac death to even young consumers.

The study involved thirty-four healthy adults aged 18 to 40 which were assigned to consume two different commercially available energy drinks or a placebo drink. Each participant drank each 32-oz beverage over 60 minutes on 3 separate days. The energy drinks each contained over 300 mg of caffeine, plus taurine, glucuronolactone, vitamins, and proprietary ingredients which is common for most energy drinks on the market. The participants were monitored by electrocardiogram for 4 hours.

The result revealed that maximum placebo-adjusted increase in QTc was 6.1 ms and 7.7 ms for each energy drink. In addition, systolic blood pressure was about 5 mm Hg higher after energy drink versus placebo consumption. The results appear to be both independent of and dependent on caffeine consumption. Energy drinks warrant concern and should be limited or avoided based on these results.

The bottom line: Researchers found an association between consuming energy drinks and changes in QT intervals and blood pressure that cannot be attributed to caffeine. There is a need to investigate the particular ingredient or combination of ingredients in different types of energy drinks, but they do not exist to this date. Consuming caffeinated energy drinks is associated with QTc interval prolongation, which is a risk factor for a life-arrhythmia. This finding warrants caution on the intake of energy drinks.