UW study asks: Can caffeine and booze cancel each other out at bedtime?

When it comes to the science of sleep, a new study from the University of Washington is busting some myths.

It looked at the effects of caffeine, then added in the wine, liquor, or beer you might also drink on the same day to see what effect it might have on the quality of your sleep.

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Researchers from UW’s Department of Psychiatry and Behavior Sciences discovered that drinking your morning coffee and then an alcoholic beverage before bed cancels the negative effects on your sleep.

But in general, it’s no surprise that drinking alcohol before bed isn’t good for you or your beauty sleep.

“What we found is, as expected, alcohol had a negative effect on sleep quality to the tune of up to 4% decline in subjective sleep quality for each glass of alcohol consumed,” said UW researcher and fourth-year clinical psychology doctoral candidate Frank Song.

In a six-week study, Song and his co-author, sleep scientist Dr. Matthew Walker, studied the effects that caffeine and alcohol consumption have in real-world scenarios with 17 people and found that consuming alcohol alone had negative effects on sleep, but when adding caffeine into the mix, there was a much different reaction.

“When you have nights of consuming both alcohol and caffeine, we had initially expected that we would find a double negative effect on quality of sleep and duration of sleep, but what we found is the opposite,” said Song.

Song and his co-author found that based on evidence they had collected, people were using caffeine and alcohol to balance out their sleep quality.

“This intrigued us because it provides an explanation for why we use these substances together,” said Song. “At the same time, it raises concerns because this is not to suggest that mixing these two substances is truly beneficial for your sleep; rather it suggests there is a misperception in the sleep state.”

And by misperception in sleep state, that means essentially the two substances are masking the negative effects on each other, making you believe that after a night of drinking, something that already negatively impacts your sleep quality by itself is offset with the illusion that you slept better because caffeine in the morning makes you feel more alert and coherent.

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