Energy drinks – usually a mixture of caffeine, taurine, carbohydrates, B-complex vitamins and gluconolactone – have become very popular in recent years. Although several studies support the widespread belief that energy drinks may enhance mood and/or improve cognitive and physical performance, very little research has investigated their purported ability to delay the depressant effects of alcohol on the central nervous system, thereby prolonging its excitatory effects.
A study in the September issue of Alcoholism: Clinical & Experimental Research has found that an energy drink called Red Bull®, when consumed jointly with alcohol, does not improve a person’s physical performance.
“In Brazil, as in other countries, the use of ‘energy drinks’ such as Red Bull is relatively common in bars and night clubs,” said Maria Lucia O. Souza Formigoni, associate professor at the Federal University of São Paulo in Brazil and corresponding author for the study. “Many young people use them mixed with vodka, whisky or other spirits.” While the combination of the two, she said, may give people the ‘sensation’ of reduced alcohol effects, their abilities are in fact compromised for complex tasks such as driving a vehicle.
“In general,” added Maristela G. Monteiro, regional advisor on alcohol and substance abuse for the Pan American Health Organization, “young people are often the target of marketing strategies. This is why it is important to monitor and research the effects of new drinks in the market on young people’s drinking behavior, as well as perceptions about alcohol and its effects on health.”
“We surveyed Brazilian nightclubs for people who consumed energy drinks, eventually interviewing 136 people,” said Formigoni. “We asked whether they used it with alcohol and, if they did so, what effects they noticed. Most of them – seventy-six percent – used energy drinks with alcoholic beverages … some reporting that they do that in order to ‘reduce’ alcohol depressant effects while others do it to ‘increase’ the alcohol stimulant effects. The main effects reported with the combined use were happiness (37%), euphoria (30%), extroversion (26%) and an increase in vigor (24%).” The results of that survey, she said, led to the current examination of the combined effects of energy drinks and alcohol on physical performance.
Researchers had 14 healthy, male volunteers complete four sessions, each one week apart, during which they received water, alcohol (1.0 g/kg), an energy drink, and alcohol plus an energy drink prior to performing a cycling test. The cycling test, which lasted until either a maximum heart rate was reached or the volunteer asked to stop, began 60 minutes after ingestion of that week’s solution. Sixty minutes after the cycling test, researchers also measured the participants’ physiological indicators (VO2, ventilatory threshold, respiratory exchange rate, heart rate and blood pressure), biochemical variables (glucose, lactate, hormones and neurotransmitters) and blood alcohol levels.