More than caffeine
Energy drinks can best be described as industrially designed soft drinks that contain multiple stimulants (ginseng, guarana, taurine, etc.) in addition to caffeine (usually 320 mg/l or more). Sugar or sweeteners hide the taste of bitter ingredients such as caffeine and taurine, making them more palatable to children and adolescents. In addition, B-vitamins are added to make the drinks seem healthy. Because energy drinks are consumed like soft drinks and contain stimulants that reinforce each other as well as carbonation which increases the speed of caffeine uptake in the blood, they are associated with a greater health risk than coffee, although coffee has more caffeine (approx. 500 mg/l).
Energy drinks are potent due to their diverse combination of stimulants. This is shown, for example, in a randomised, double-blind, controlled crossover study that measured the effect of an energy drink and a caffeinated control drink, both containing 320 mg/l caffeine, on 18 healthy young adults. Two hours after intake of the energy drink, the research subjects showed a significantly longer QT interval, a risk factor for fatal heart arrhythmia, than after intake of the same amount of the caffeinated drink. Both drinks caused an increase in systolic blood pressure, but six hours after consumption this figure was significantly higher for the energy drink than for the caffeinated drink (5). The combination of caffeine and other ingredients, such as sugar, may be a contributing cause of the serious effect; however, more research is needed to confirm the potentially causal link between the agents. It is extremely regrettable that children and adolescents have unrestricted access to addictive products that increase blood pressure and, in the worst case, cause serious heart arrhythmia.