Energy drinks are popular among athletes, students pulling an all-nighter and new parents catching up on lost sleep. However, a new study says energy drinks may cause serious increases in heart contraction rates within an hour of drinking the beverage.
Researchers at the University of Bonn in Germany measured contraction rates in the left ventricle, which is important in pumping blood to the aorta, using MRI. Heart rate and blood pressure were recorded throughout the investigation. According to the study, which was presented on Monday at the annual meeting of the Radiological Society of North America (RSNA), drinks with high amounts of caffeine and taurine caused significant increases in heart strain one hour after consumption.
"Until now, we haven't known exactly what effect these energy drinks have on the function of the heart," said study researcher Dr. Jonas Dörner, of the cardiovascular imaging section at the University of Bonn in Germany. "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."
The researchers gave the participants a drink containing 32mg per 100ml of caffeine and 400mg per 100ml of another chemical, taurine.
The study comes on the heels of another report published earlier this year by the Substance Abuse and Mental Health Services Administration (SAMHSA) which reported the number of emergency department visits related to energy drinks in the US essentially doubled, from 10,000 to almost 21,000, between 2007 and 2011.
"Usually energy drinks contain taurine and caffeine as their main pharmacological ingredients," Dörner said. "The amount of caffeine is up to three times higher than in other caffeinated beverages like coffee or cola. There are many side effects known to be associated with a high intake of caffeine, including rapid heart rate, palpitations, rise in blood pressure and, in the most severe cases, seizures or sudden death."
