March 27, 2006 -- If you drink alcohol, don't count on energy drinks such as Red Bull to keep you sober.
In a new study, young, healthy men reported feeling less drunk when they drank vodka mixed with Red Bull. But those impressions were misleading.
"The person is drunk but does not feel as drunk as he really is," says researcher Maria Lucia Souza-Formigoni, PhD, in a news release.
"People need to understand that the 'sensation' of well-being does not necessarily mean that they are unaffected by alcohol," Souza-Formigoni says, warning drinkers not to get behind the wheel. "Despite how good they may feel, they shouldn't drink and drive. Never."
Red Bull and other energy drinks don't claim to override alcohol's effects.
But energy drinks are often served with alcohol in night clubs, says Souza-Formigoni, who works in the psychobiology department of Brazil's Federal University of Sao Paolo.
"In Brazil, as in other countries, young people believe that Red Bull and other energy drinks [help them] avoid the sleepiness caused by alcoholic beverages and increase their capacity to dance all night," Souza-Formigoni says.
Her study included 26 healthy young men who were about 23 years old. In a lab, the men drank Red Bull, vodka, or Red Bull mixed with vodka. Each man drank one drink per session, waiting at least a week between sessions. The drinks looked and tasted the same, so no one could tell which was which.
The tests were done at midday in a lab. Before each test, the researchers fed each man a Big Mac, fries, and a soft drink. Afterward, the men got a snack of fruit juice, bread, cookies, and coffee before being taken home by taxi.
Before drinking anything, the men took breath-alcohol tests. All were sober. They also took several other tests:
- Coordination: Remove 25 pegs from a pegboard.
- Visual reaction: Click a computer key when a yellow square appeared on the computer screen.
- Self-rated drunkenness: Rate feelings including tiredness, headache, dizziness, nausea, weakness, agitation, and problems with breathing or walking.
The men drank whatever they'd been given for 10 to 20 minutes. Then they took the tests repeatedly over the next 2.5 hours.
The goal was to see if the men felt as drunk as they actually were, and if the results changed when vodka and Red Bull were mixed.
Drunk and in Denial
But actually, they weren't more coordinated after drinking Red Bull and vodka than with vodka alone. Visual reaction times and breath-alcohol levels weren't better, either, when vodka was mixed with Red Bull, the study shows.
Few studies have been done on alcohol and energy drinks, note the researchers, who only tested store-bought Red Bull. Souza-Formigoni and colleagues write that they're not sure if the caffeine or other ingredients in energy drinks is what may make people falsely feel less drunk than they really are.