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.
Results indicate that the energy drink tested in this study, when consumed jointly with alcohol, did not improve performance (in this case, cycling) or reduce physiological and biochemical alterations induced by alcohol ingestion.
“I think the main message of our study is that this kind of beverage, at least in the tested doses, does not increase people’s performance in physical activities or reduce alterations induced by acute alcohol ingestion,” said Formigoni.
“Young people should continue to be careful when using these drinks together until more evidence is available,” added Monteiro. “We need more research with a variety of drinks on cognitive performance, reflecting the common usage of the drinks, which would help clarify their potential adverse or beneficial effects. Research on young women, who are often the target of marketing strategies with such drinks and combination of drinks, should also be a priority; the present study included only male subjects. It would also be interesting to know if subjects felt differently in each session and how the interaction of the drinks could have affected their perception of time, memory, dexterity and so on. For example, the effects of the combination on driving-related skills should be further investigated. Finally, developing animal models for testing higher doses of alcohol, which may limit the study in volunteers, would also be good.”
This is in fact what Formigoni and her colleagues are currently examining, the effects on mice of different doses of energy drinks and alcohol. “We expect to publish those results in the near future,” she said.
