24090620

PMC3864634

1R49CE000946/CE/NCIPC CDC HHS/United States
M01 RR000533/RR/NCRR NIH HHS/United States
M01 RR00533/RR/NCRR NIH HHS/United States

CDC Public Access

Aims

Beliefs about the effects of mixing caffeine and alcohol on hangover or sleep may play a role in motivation to consume these mixtures; therefore, information is needed about actual effects. We investigated whether intoxication with caffeinated vs. non-caffeinated beer differentially affected perceived sleep quality, sleepiness, and hangover incidence and severity the next morning.

Methods

University students (89%) and recent graduate drinkers were randomized to receive: (1) beer with the equivalent of 69 mg caffeine/12 oz glass of regular beer (n = 28) or (2) beer without caffeine (n = 36), in sufficient quantity to attain a BrAC of 0.12 g%. After an 8-hour supervised sleep period, participants completed measures of hangover, sleep quality, sleep latency and time asleep, and sleepiness.

Results

While caffeinated beer improved perceived sleep quality, effect sizes were greater for morning alertness than for quality while sleeping, with no effect on sleep latency or total sleep time. No effects were seen on hangover incidence or severity.

Conclusions

Mixing caffeine and alcohol does not significantly impair amount of sleep or sleep latency, hangover, or sleepiness the morning after drinking to intoxication in this population.