How alcohol and caffeine interact to affect sleep

Drinking either substance measurably affects snoozing, but in tandem yields an interesting result, a new study found.

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A new study, believed by its researchers to be among the first to examine the combined effects of alcohol and caffeine intake on sleep, found that the two popular substances take unique tolls on slumber. What's more, participants who routinely drank both on a typical day reported comparatively less negative impact from alcohol (on sleep quality) and from caffeine (on sleep duration).  

“The most intriguing finding from this study is that the interaction between the two substances, unlike what we had predicted, it ended up being positive (initially) — such that having both caffeine and alcohol in the same night had a mitigating effect on each other's negative effects on sleep,” said Frank Song, a researcher at UW Medicine’s Center for the Study of Health and Risk Behavior.   

But this experience, Song said, appeared to be short-lived.  

“In the long run, it actually perpetuates this cycle of alcohol and caffeine use while the individuals are unaware of their negative effect on sleep,” said Song.  

Learn more about the study in our news release

Download broadcast-ready soundbites with Song talking about this study of the effects of alcohol and caffeine on sleep.

UW Medicine