When it comes to drinking energy drinks the American Heart Association is warning people to proceed with caution after a recent small study found a connection between consuming energy drinks and elevated blood pressure and increased risk of electrical disturbances in the heart, affecting heart rhythm.
In a study of 34 healthy volunteers ages 18-40, participants were randomly given 32 ounces of two commercially available caffeinated energy drinks or a placebo drink on three separate days. Researchers measured the volunteers’ blood pressure and heart electrical activity at the study’s start and every 30 minutes for four hours after the drinks were consumed. They saw a 4-5 mm Hg increase in blood pressure in the participants who had consumed the energy drinks, as well as higher QT intervals, which can cause the heart to beat abnormally.
“The public should be aware of the impact of energy drinks on their body, especially if they have other underlying health conditions,” said lead author Sachin A. Shah, Pharm.D., professor of pharmacy practice at the University of the Pacific, Thomas J. Long School of Pharmacy and Health Sciences in Stockton, California.
Caffeine doses below 400 milligrams are not expected to cause electrocardiographic changes. The energy drinks provided in the study contained 304-320 milligrams of caffeine, well below that ceiling. Researchers say this means the results seen in the study cannot be contributed to caffeine, and more investigation is needed to identify what ingredient in energy drinks may be causing these results.
The study’s size is one of its limitations as it only included healthy individuals ages 18-40. Results may vary by population, AHA says. The study also focused on the short-term effects of energy drink consumption, and more research would be needed to identify long-term effects.