CORONA, Calif. -- Calling the findings "alarmist and misleading," Monster Beverage Corp. has released a statement in response to a paper presented at the Chicago-based Radiological Society of North America's annual meeting that claims energy drinks alter heart function.
The paper, "Caffeine & Taurine Containing Energy Drink Improves Systolic Left-ventricular Contractility in Healthy Volunteers Assessed by Strain Analysis Using Cardiac Magnetic Resonance Tagging," said that healthy adults who consumed energy drinks high in caffeine and taurine had significantly increased heart contraction rates one hour later.
"Until now, we haven't known exactly what effect these energy drinks have on the function of the heart," said radiology resident Jonas Dörner, M.D., of the cardiovascular imaging section at the University of Bonn, Germany, which is led by the study's principal investigator, Daniel K. Thomas, M.D. "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."
A 2013 report from the Substance Abuse & Mental Health Services Administration stated that in the U.S. from 2007 to 2011, the number of emergency department visits related to energy drink consumption nearly doubled, increasing from 10,068 to 20,783. Most of the cases were identified among patients aged 18 to 25, followed by those aged 26 to 39.
"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."
For the study, which is ongoing, Dörner and colleagues used cardiac magnetic resonance imaging (MRI) to measure the effect of energy drink consumption on heart function in 18 healthy volunteers, including 15 men and three women with a mean age of 27.5 years. Each of the volunteers underwent cardiac MRI before and one hour after consuming an energy drink containing taurine (400 mg/100 ml) and caffeine (32 mg/100 ml).
Compared to the baseline images, results of cardiac MRI performed one hour after the study participants consumed the energy drink revealed significantly increased peak strain and peak systolic strain rates (measurements for contractility) in the left ventricle of the heart. The heart's left ventricle receives oxygenated blood from the lungs and pumps it to the aorta, which distributes it throughout the rest of the body.
"We don't know exactly how or if this greater contractility of the heart impacts daily activities or athletic performance," Dörner said. "We need additional studies to understand this mechanism and to determine how long the effect of the energy drink lasts."
The researchers found no significant differences in heart rate, blood pressure or the amount of blood ejected from the left ventricle of the heart between the volunteers' baseline and second MRI exams.
"We've shown that energy drink consumption has a short-term impact on cardiac contractility," Dörner said. "Further studies are needed to evaluate the impact of long-term energy drink consumption and the effect of such drinks on individuals with heart disease."
Dörner said that while long-term risks to the heart from drinking energy drinks remain unknown, he advises that children, as well as people with known cardiac arrhythmias, should avoid energy drinks, because changes in contractility could trigger arrhythmias.
Monster Beverage's statement:
"The Dec. 2 presentation to the [RSNA] by Jonas Dorner, a radiologist in training at the University of Bonn, is alarmist and misleading, according to Monster Beverage independent medical consultants Robert Arnot, M.D., and Michael H. Forman, M.D. The paper offers no new information and confirms what scientists have known for decades: Taurine helps the heart function more efficiently by improving the pumping force of the heart without any changes in blood pressure or heart rate. This effect of taurine, called contractility, is widely considered to be beneficial. In fact, peer reviewed studies demonstrate that taurine has been used effectively to treat patients with congestive heart failure and to improve athletic performance.
"The author's study does not document a negative effect on heart function. Although he concludes that the consumption of energy drinks should be restricted based on his study, this conclusion is unsupported by his data and highly misleading. No evidence exists that increased contractility causes arrhythmia.
"Additionally, the statement regarding energy drinks by author Jonas Dorner that, 'The amount of caffeine is up to three times higher than in other caffeinated beverages like coffee or cola' is false and inaccurate. Ounce per ounce, leading energy drinks contain about half the caffeine of coffeehouse coffee, such as Starbucks. In commenting on the author's false statement about caffeine, Forbes also reports today: 'This study does not document any harmful or lasting effects from consuming energy drinks'."
Based in Corona, Calif., Monster Beverage is a marketer and distributor of energy drinks and alternative beverages. It markets and distributes Monster Energy brand energy drinks, Monster Energy Extra Strength Nitrous Technology brand energy drinks, Java Monster brand non-carbonated coffee + energy drinks, X-Presso Monster brand non-carbonated espresso energy drinks, M3 Monster Energy Super Concentrate energy drinks, Monster Rehab noncarbonated energy drinks with electrolytes, Ubermonster energy drinks, Worx Energy shots, and Peace Tea iced teas, as well as Hansen's natural sodas, apple juice and juice blends, multi-vitamin juices, Junior Juice beverages, Blue Sky beverages, Hubert's Lemonades, Vidration vitamin enhanced waters and PRE Probiotic drinks.
Members help make our journalism possible. Become a CSP member today and unlock exclusive benefits, including unlimited access to all of our content. Sign up here.