Energy drinks mask, but don't prevent, intoxication, MedPage Today reported March 27.

Using drinks like Red Bull as mixers has become popular, but researchers say that while drinkers may feel fewer effects of intoxication thanks to the stimulating effect of energy drinks, they're actually just as drunk as if they had consumed other mixers.

The study compared men who drank Red Bull alone, Red Bull mixed with vodka, and straight vodka. Those who drink Red Bull mixed with vodka reported feeling less drunk than those who consumed straight vodka, but objective measures found equal levels of intoxication.

Researcher Maria Lucia O. Souza-Formigoni, Ph.D., of Federal University of Sao Paulo Sino in Brazil said that Red Bull/vodka drinkers felt less tired, but the alcohol still impaired their motor coordination. "In other words, the person is drunk but does not feel as drunk as he really is," Souza-Formigoni and colleagues wrote. "The second important point is that many users reported using energy drinks to reduce a not-so-pleasant taste of alcoholic beverages, which could dangerously increase the amount (as well as the speed of ingestion) of alcoholic beverages."

The research appears in the April 2006 issue of Alcoholism: Clinical and Experimental Research.