Wine assists sleep after drinking coffee
The relationship between wine and coffee could be beneficial for sleep patterns, a new scientific study has discovered.
Most people will indulge in a cup or two of coffee throughout the day, and then a glass or two of wine at night, but what are the impacts of these drinking habits?
In one of the first studies of its kind, published in journal PLOS One, scientists looked at the combined impact of alcohol and caffeine on nightly sleep.
According to researchers at the University of Washington and the University of California, Berkeley, 90% of adults had at least one caffeinated drink a week, while 74% of people 15 and over regularly have a drink containing alcohol.
Coffee and alcohol
Scientists expected based on previous research the combination of the world’s two most popular psychoactive drugs would negatively impact sleep. But their study of financial traders discovered an unusual result.
Researcher Frank Song from the study said to Mirage News: “Compared to the nights when you might have one or the other, we thought we were going to see additional decline in subjective sleep quality or sleep duration.
“But actually, that interaction effect was the opposite of what we expected and ended up having an effect of offsetting each other’s negative impact on quality or quantity. And this was very intriguing to us.”
He said some participants showed signs of self-medicating with the effects of one drug to overcome the other. However, although in the short term it appeared to create greater alertness by using caffeine to “wipe off the hangover”, in the longer term it was less positive.
The group of 17 financial traders logged their drinks consumption, and both independent use of caffeine and alcohol were logged. Caffeine reduced sleep quantity by 10 minutes per cup, alcohol reported a 4% decline. But when these drinks were in combination, the results were unexpected.
The scientists reported: “Having tested the independent contributions of caffeine and alcohol consumption on sleep, we next sought to examine the dual, interacting effects of combined-use caffeine and alcohol on night-time sleep, rather than either alone.
“Somewhat contrary to the hypothesis prediction, when alcohol was consumed in combination with prior caffeine consumption, the interaction between the two substances had a positive effect on subjective sleep quality. This would suggest that the known sedative influence of alcohol may mask the otherwise detrimental psychoactive alerting impact of prior caffeine consumption on overall subjective sleep quality.
“Therefore, the daytime stimulant effects of caffeine and the night-time sedating effects of alcohol may act to leave the subjective perception of sleep quality indifferent.”