Hold the Red Bull: Energy Drinks Don't Blunt Effects of Alcohol, Study Finds

Marketing efforts that encourage mixing caffeinated "energy" drinks with alcohol often try to sway young people to believe that caffeine will offset the sedating effects of alcohol and increase alertness and stamina.

But a new study led by researchers from the Boston University School of Public Health and the Center for Alcohol and Addiction Studies at Brown University has found that the addition of caffeine to alcohol - mixing Red Bull with vodka, for example - has no effect on enhancing performance on a driving test or improving sustained attention or reaction times.

"There appears to be little or no protective benefit from the addition of caffeine to alcohol, with respect to the safe execution of activities that require sustained attention with rapid, accurate decisions," says the study, published in the February edition of the journal Addiction.

"The results of this study suggest that public education, via media and warning labels, should be considered regarding the safety of CABs [caffeinated alcoholic beverages], and that regulators should scrutinize energy drink and CAB advertising as it relates to promoting safety-related expectancies."

The study, headed by Jonathan Howland, professor of community health sciences at BUSPH, comes amid increased government scrutiny of energy drinks, particularly when mixed with alcohol. Denmark has banned the sale of energy drinks, and the governments of Canada and Sweden have issued warnings about mixing energy drinks with alcohol.

In 2009, the US Food and Drug Administration issued a statement expressing concern about a lack of safety data on CABs, after survey results showed that the consumption of such beverages correlated with risky behavior among college students.

Howland and his co-authors note that while energy drink companies do not explicitly advertise that their products should be mixed with alcohol, "non-traditional youth-oriented marketing strategies" include claims that such drinks will "enhance attention, endurance, performance, weight loss, and fun, while reducing performance decrements from fatigue from alcohol."

In the new study, the research team randomized 129 participants, ages 21 to 30, into four groups: one group that consumed caffeinated beer; a second that consumed non-caffeinated beer; a third that consumed caffeinated non-alcoholic beer; and a fourth that consumed non-caffeinated, non-alcoholic beer. Those receiving alcohol attained an average blood alcohol level of .12 grams percent - somewhat higher than 0.8 grams percent, the legal per se level for driving under the influence.

Thirty minutes after drinking, the participants were tested on a driving simulator and on a sustained attention/reaction time test.

The results indicate that caffeine does not mitigate the impairment effects of alcohol. On the driving test, the effect of alcohol on performance was significant - but the addition of caffeine did not make a noticeable difference. On the test for sustained attention and reaction times, the addition of caffeine made only a slight difference that the study deemed "borderline significant."