Healthy adults who consumed energy drinks high in caffeine and taurine had significantly increased heart contraction rates one hour later, according to a study presented at the annual meeting of the Radiological Society of North America.
“Until now, we haven’t known exactly what effect these energy drinks have on the function of the heart,” Jonas Dörner, one of the study’s authors, said in a press release accompanying the research. “There are concerns about the products’ potential adverse side effects on heart function, especially in adolescents and young adults, but there is little or no regulation of energy drink sales.”
For the study, researchers used MRIs to measure the effect of energy drink consumption on heart function in 18 healthy volunteers (15 men, three women) with an average age of 27.5. Each of the volunteers underwent cardiac MRI before and one hour after consuming an energy drink containing taurine (400mg/100ml) and caffeine (32mg/100ml). Those amounts are similar to the caffeine and taurine content of Red Bull, one of the most popular energy drinks.
The post-drink MRIs revealed significantly increased peak strain and peak systolic strain rates (measurements for contractility) in the left ventricle of the heart. “We don’t know exactly how or if this greater contractility of the heart impacts daily activities or athletic performance,” Dörner said.
Emergency-room visits related to energy drinks doubled between 2007 and 2011.
Setting aside potential health risks, research published last year called into question whether most of the substances commonly added to energy drinks work as claimed. That research found “an overwhelming lack of evidence to substantiate claims that components of energy drinks [often including taurine, various vitamins, and yerba mate], other than caffeine, contribute to the enhancement of physical or cognitive performance.”