Energy drinks work differently than caffeine drinks: Scientists suspect combination effects
Energy drinks can have a greater effect on blood pressure than drinks that contain only caffeine, a double-blind study published in spring 2017 by pharmacologists from the University of the Pacific in California showed. 18 young and healthy men and women took part in the study. They were divided into two groups: the test group drank a liter of a commercial energy drink in 45 minutes.
The caffeine content of this drink was 320 mg, the sugar content was around 110 g. The control group received a drink of 320 mg caffeine, 40 milliliters of lemon juice and 140 milliliters of cherry syrup in carbonated water. After a week there was a change. The scientists then examined the heart's blood pressure and QT interval. This is the time it takes for the heart to regenerate from the electrical impulse that triggered the heartbeat (regression of arousal).
The control group's blood pressure returned to normal after six hours. The group of energy drink users, however, still had a slightly elevated blood pressure even after six hours. The energy drinks also had a stronger effect on the QT interval. Two hours after consuming the energy drink, the regression in the test group continued for 10 milliseconds longer than in the control group. "Medications that lead to an extension of the QT time of 6 milliseconds must already carry warnings," explains Emily Fletcher, the lead author of the study in a press release from the university. A 60 millisecond extension is a risk of life-threatening arrhythmias.
These effects cannot be attributed to caffeine alone, the scientists suspect. They assume that other ingredients of the energy drink such as taurine, carnitine and ginseng also contribute to these results, because they have opposite effects in the body. The scientists do not yet consider extending the QT period as dangerous because it is only temporary. However, such effects could be risky for certain groups of people, for example in people who take heart medication or who are deficient in potassium or magnesium.
The team led by Emily Fletcher and Sachin Shah from Travis Air Force Base had already dealt with the health effects of energy drinks. Because 75 percent of the members of the army drink energy drinks, 15% even three doses a day. "This is more than we used in our experiment," says Fletcher.
The results should be enjoyed with caution, write them in their publication. Larger clinical trials would have to be carried out to secure them. You should not only examine the effects of caffeine, but also that of the other ingredients. People with high blood pressure or other health problems should better stay away from energy drinks, she recommends. Gesa Maschkowski, resp