Mixing caffeinated 'energy' drinks with alcohol has no effect on enhancing performance on a driving test or improving sustained attention or reaction times, a new study has suggested.
"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," said the study conducted by Boston University School of Public Health and the Center for Alcohol and Addiction Studies at Brown University.
The study, headed by Jonathan Howland, BUSPH, comes amid increased government scrutiny of energy drinks, particularly when mixed with alcohol.
Howland and his co-authors noted 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.
The results indicated 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."
The study was published in the journal Addiction.