29 May 2019 --- The increased blood pressure and impacted heart rhythms that resulted from healthy volunteers drinking about two cans – 32 ounces– of energy drink in a short timespan cannot be attributable to caffeine. This is according to a small study published in Journal of the American Heart Association (AHA), the Open Access Journal of the AHA. The researchers warn that more research is needed to investigate which energy beverage ingredient causes fluctuations in heart health. They are, therefore, calling for urgent further research.