Approach Nightcaps With Caution
Alcohol’s relationship to sleep is extremely complicated. Although it’s been studied since the 1930s, scientists are still searching for answers about the relationship alcohol has with your sleep quality. All of those studies have taught us a few things, though.
First, alcohol makes it easier to fall asleep quickly. That’s true whether you have one drink or several. Second, alcohol disrupts your second half of sleep. Wondering why? One theory suggests your body adapts to the sedative effects of alcohol during the first half of your sleep cycle, and continues to attempt to adapt during the second half even though it has processed the alcohol out of your bloodstream. Third, when you drink a moderate to high amount of alcohol, your REM sleep stage shortens (your dreaming stage), while your slow wave sleep increases. Fourth, your body becomes more resistant to the sleep-inducing effects of alcohol after just three nights of drinking.
There are hints of other effects, too, that are less well-established. If you drink heavily, you may be more likely to snore, and that can harm your sleep quality. You may also wake up more frequently and earlier after a night of heavy drinking. You may be less rested the next day, and this may slightly impair your concentration. (Even a slight impairment can cause problems in a demanding job like air traffic control). It’s possible that insomniacs sleep better with one to two drinks before bed, but the same amount may be more disruptive for healthy adults. Seniors should be particularly cautious around alcohol at bedtime, because they require less alcohol to feel the same effects, and because they may wake up still under the effect of alcohol, which increases their risk of falling.