The leader of a research team that measured the acute effects of energy drinks on heart function emphasizes that he never said those effects were dangerous, although press coverage of the study viewed the findings with alarm. Responding to criticism from Monster Beverage, which called the study "alarmist and misleading," University of Bonn radiologist Daniel Thomas tells Food Navigator:
Although energy drinks have previously been shown to enhance athletes' endurance, this is the first study using advanced imaging technology…to directly demonstrate the impact of an energy drink on myocardial contraction. Whether this increase in contractility is generally beneficial or not cannot be deducted from our study or from the current literature but warrants further investigation. Specifically, the dose dependency of this effect and long-term effects have yet to be investigated.
It's true that the study, which has not been published yet but was summarized at a recent meeting of the Radiological Society of North America, does not demonstrate any harmful effects from consuming energy drinks. But in a press release issued by the society, Thomas' collaborator, Jonas Dorner, suggested otherwise, saying, "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 press release reinforced this negative impression by citing an increase in "emergency department visits related to energy drink consumption." Dorner made sure the study would be portrayed as yet more evidence that energy drinks are a public health menace by adding, "The amount of caffeine [in energy drinks] 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."
As I pointed out on Monday, Dorner's statement that energy drinks contain more caffeine than coffee is flat-out wrong: In fact, coffee contains a lot more caffeine per milliliter than energy drinks do—more than twice as much, based on a comparison of Starbucks coffee and the energy drink used in Thomas and Dorner's study. That point is crucial because the health concerns raised by Dorner are health concerns about caffeine, meaning the emphasis on energy drinks cannot be rationally justified. The relative doses suggest exactly the opposite of what Dorner implied: If caffeine is the problem, energy drinks are demonstrably safer than coffee.