One of the most basic and important topics I write about, and emphasize to my patients, is the idea of sleep hygiene. Sleep hygiene means a routine of healthy, sleep-promoting habits that prepare and enable you to consistently receive a sound, full and restful night of sleep. When I talk about sleep hygiene, I'm not only encouraging good sleep habits, but encouraging making changes that don't promote good quality sleep. One of the changes I find myself talking about most often has to do with alcohol consumption before bedtime.
Research suggests that alcohol is the most widely used sleep aid in the world, and yet we have ample evidence that alcohol is disruptive and problematic for sleep. Sure, a drink (or two) not long before bed may make you fall asleep more quickly, but as the night wears on, you're likely to miss out on deep sleep, to wake more frequently throughout the night and to feel tired the next day. The results of two recent studies provide yet more confirmation of the obstacles that alcohol can pose for sleep.
One small study in Japan examined the effects of alcohol on sleep in 10 university students. The students, all male and in good health, were divided into three groups. One group went to sleep without consuming any alcohol. The second group was given a low dose of alcohol (as measured by body weight) and the third group was given a high dose of alcohol, consumed 100 minutes before bedtime. Researchers then measured sleepers' heart rate and heart rate variability, and monitored participants' sleep through a polysomnogram. What did they find?
• The students who consumed alcohol fell asleep quickly, but as the night wore on their sleep was shallow and disrupted, compared to those who did not drink before bed.
• Alcohol consumption resulted in increased heart rate, and range of heart rate variability (a measure of the time intervals between individual heartbeats). The more alcohol consumed, the more heart rate increased.
Researchers concluded that the presence of alcohol acted as a stimulant (increased heart rate) and kept them from being to transition into a resting and restorative state, and getting into the deepest stages of sleep.
This study was a small one, but its overall results align with the recently published results of a larger study that also examined the effects of alcohol on sleep among young adults. In this study, researchers were looking in particular at the effects of intoxication on sleep, and if those effects were influenced by a couple of additional factors: gender and a family history of alcoholism. Researchers had 93 men and women in their early-to-mid 20s drink to the point of intoxication, and measured the quality, depth and duration of their sleep under the influence. They found that while intoxicated, participants:
• Slept less than when sober
• Woke up more frequently throughout the night
• Felt more tired in the morning, and sleepier at the end of the next day
• Received most of their sleep during the first half of the night
• Spent less time in REM sleep
Researchers found no difference in the sleep habits of participants with a family history of alcoholism. They did find differences when it came to gender, however. Alcohol had a greater disruptive influence on women's sleep than on men's, particularly when it came to feeling sleep deprived the next day. This is yet another indication that women and men experience sleep very differently, and often with distinct health consequences.
These results don't mean that none of us should ever have a glass of wine with dinner, or a beer after work. I'm not advocating, in general, for this kind of across-the board teetotaling. But there are some basic guidelines you can follow that will help prevent your alcohol consumption from interfering with your sleep:
A glass for a glass: For every alcoholic drink you consume, also drink a glass of water.
Cork the bottle early. Don't drink alcohol within three hours of bedtime.
Break the bedtime habit. Avoid using alcohol directly as a sleep aid. Instead, look for other relaxation aids -- music, meditation -- that will promote healthy sleep.
By understanding how alcohol affects your body -- and why its temporary lulling effects aren't actually a path to real rest -- it's possible enjoy your favorite spirit in moderation, and still protect the quality of your sleep. Cheers to that!
Michael J. Breus, Ph.D.
The Sleep Doctor™
Everything you do, you do better with a good night's sleep™