A study has found that drinking before sleep results in an increase in frontal alpha power in the brain, a development which is associated with disturbed sleep.
For individuals who drink before sleeping, alcohol initially acts as a sedative – marked by the delta frequency electroencephalogram (EEG) activity of Slow Wave Sleep (SWS) – but is later associated with sleep disruption.
"People likely tend to focus on the commonly reported sedative properties of alcohol, which is reflected in shorter times to fall asleep, particularly in adults, rather than the sleep disruption that occurs later in the night," said Christian L. Nicholas from the University of Melbourne in Australia.
For the study, the team recruited 24 participants, healthy 18- to 21-year-old social drinkers who had consumed less than seven standard drinks per week during the previous 30 days.
Each participant underwent two conditions: pre-sleep alcohol as well as a placebo followed by standard polysomnography (a multi-parametric test used in the study of sleep) with comprehensive EEG recordings.
Alcohol significantly increased frontal alpha power, showed the results.
"The take-home message here is that alcohol is not actually a particularly good sleep aid even though it may seem like it helps you get to sleep quicker. In fact, the quality of the sleep you get is significantly altered and disrupted," said Nicholas.
The study is forthcoming in the journal Alcoholism: Clinical & Experimental Research.