"Drinking alcohol helps you sleep well" is the biggest misunderstanding in brain science
The kids are asleep.
Finally, some time to myself. I sit on the sofa and take a can out of the fridge. I let out a sigh. "I made it through today because of this." A little drink helps my body relax. My eyes start to feel heavy. "I really do sleep better when I drink."
I truly understand that feeling.
However, in reality—from the perspective of brain science, this isn't "sleeping well," it's just "losing consciousness."
Being "put to sleep" and "being able to sleep" are completely different things.And alcohol is the former, not the latter. Today, I will explain how that mechanism works.
◎ Alcohol "putting you to sleep" and "being able to sleep" are completely different things
Alcohol acts as a "sedative" that suppresses brain activity. The reason you feel drowsy after drinking is not because your brain has "fallen asleep," but because it has been "suppressed."
Dr. Walker (Walker, 2017) analyzed sleep brain waves after alcohol consumption and stated: "Sleep induced by alcohol is not natural sleep, but a state close to anesthesia."
Just as someone who has been anesthetized would not say they "slept well," consciousness lost due to alcohol does not equate to "high-quality sleep." When viewed through brain waves, sleep after alcohol lacks the waveforms of natural deep sleep, leaving the brain in a state where it "seems to be sleeping, but is not resting sufficiently."
"I don't feel refreshed the next morning after drinking," "I feel tired even though I slept"—that feeling is correct. Your brain is not actually resting.
◎ REM sleep is completely stripped away
The greatest damage alcohol inflicts on sleep is the suppression of REM sleep.
REM sleep (dreaming sleep) is a particularly important stage of sleep involved in emotional processing, memory consolidation, restoration of creativity, and brain repair. Alcohol strongly suppresses this REM sleep.
A meta-analysis by Ebrahim et al. (2013) shows that as alcohol intake increases, the proportion of REM sleep decreases. There is even data suggesting that even a single glass of wine reduces REM sleep by an average of 24%.
What happens when REM sleep is taken away?
You start the next day without your emotions being reset. Yesterday's irritation lingers. You become more prone to anger over trivial things. You become harsher with your children. Your conversations with your spouse become awkward—if you feel that "for some reason, I'm not doing well the day after I drink," the suppression of REM sleep may be the cause.
◎ The reason why "the latter half of sleep" collapses
Another problem with alcohol is its "impact on the latter half of sleep."
There is a substance called "acetaldehyde" that is produced during the process of breaking down alcohol. When this is metabolized in the body, it has a stimulating effect on the nerves. Three to four hours after drinking alcohol, just as you are entering the second half of your sleep, the metabolism of this acetaldehyde becomes active.
As a result—you wake up in the middle of the night. Your sleep becomes shallow. You have an excessive number of dreams. You wake up repeatedly toward morning.
I think many people have had the experience of "waking up a lot in the middle of the night on days I drink." That is the work of acetaldehyde.Instead of helping you fall asleep faster, alcohol completely destroys the latter half of your sleep.
◎ "A small amount is fine" was also a fantasy
"It's just a little bit" or "Just one beer"—that feeling is also dangerous from the perspective of brain science.
In the aforementioned study by Ebrahim et al., a reduction in REM sleep was confirmed even with a "small (low dose) amount of alcohol." In other words, it is not that "drinking a little has a negligible effect on sleep"; even a small amount causes a decline in quality.
Everyone is the manager of their "own body." The decision that "it's okay because it's a small amount" might mean you are continuing to pay costs that you cannot see.
Enjoying alcohol itself is not a bad thing. However, I want you to know the "cost" of designing your sleep on the misconception that "drinking alcohol helps you sleep well."
◎ "When I stopped drinking at night, the lightness of my head the next morning was completely different"
Let me tell you about a mother in her 30s.
There was someone who said, "It was a habit to drink one or two cans of beer every night, and I felt like I couldn't sleep without it." She thought, "I can't sleep unless I drink, and I am able to sleep thanks to drinking."
I had her stop drinking before bed for just two weeks. For the first three or four days, it was true that it took a little longer to fall asleep. But after a week, she told me, "The lightness of my head the next morning is completely different. I realized that I wasn't actually sleeping when I was drinking to fall asleep."
Enjoying things is a way to heal yourself—it is fine to have time to enjoy alcohol. However, when you stop using it as a "means for sleep," true sleep and recovery begin.
◎ Summary
I will organize what I have conveyed today into three points.
・Alcohol is a "sedative," not a sleep inducer. It causes you to lose consciousness, but your brain is not resting
・It suppresses REM sleep, significantly lowering emotional processing, memory consolidation, and the next day's performance
・The metabolism of acetaldehyde causes the latter half of sleep to collapse. Even a small amount has that effect
Sleep is a skill and a tool. From "sleeping with alcohol" to "sleeping with your own power"—that one step will change who you are the next morning.
——Go ahead and enjoy yourself again today
■ References
・Walker, M. (2017). Why We Sleep: Unlocking the Power of Sleep and Dreams. Scribner.
・Ebrahim, I. O., et al. (2013). Alcohol and sleep I: Effects on normal sleep. Alcoholism: Clinical and Experimental Research, 37(4), 539-549.
・Roehrs, T., & Roth, T. (2001). Sleep, sleepiness, and alcohol use. Alcohol Research & Health, 25(2), 101-109.