What Effect Has a Glass of Wine on Your Sleep?
I am a wine lover and really appreciate a glass of wine in the evening. And for a long time, I thought wine is also a perfect sleep aid. The slightly drowsy feeling a glass of Cabernet Sauvignon can give you seemed to be an ideal way to doze off.
Until I found out that the exact opposite is the case. The truth is, drinking wine, beer or liquor close to bedtime is much more likely to interfere with your sleep than to assist it. Even consumed only in moderate doses alcohol has the power to affect your entire night of sleep.
This doesn’t mean that you have to abstain from alcohol completely. But if you use alcohol as a coping mechanism for having difficulties to fall asleep, it’s time to manage your alcohol consumption, so it doesn’t disrupt your sleep.
How does alcohol affect your sleep?
Alcohol is a sedative and therefore works pretty much like a sleeping pill. This might be a bit confusing, as we all know that a glass of wine or beer – meaning alcohol in moderate doses – has more of an energizing effect and often helps us to become more social. A few drinks give you a buzz and can spark elation and excitement. How can a sedative raise your spirits?
The answer is that alcohol works in both directions: initially as a stimulant but then as a potent depressant. When you start drinking, the alcohol leads to a decreased activity in the prefrontal cortex, the region in your brain responsible for decision making and rational thought. If this part of your brain becomes immobilized by alcohol, you start to behave less controlled and more extroverted, or – in case of higher alcohol levels in your bloodstream – even to act without thinking.
When you start drinking, alcohol initially increases the release of dopamine, which creates a pleasurable sensation. You will feel relaxed but also experience some minor impairment of reasoning and memory.
However, while you are still enjoying your initial buzz, the alcohol is already busy to sedate just about every other part of the brain, further slowing down communication in the brain. As a result, your ability to remain conscious decreases, and you slip into a sleep-like unconscious state. A clear indication that alcohol shares the same properties with classical depressants, like for example valium.
And it is true, just like a sleeping pill alcohol reduces your sleep onset latency, meaning that sleep happens more quickly after you had a drink or two.
Why is alcohol no appropriate sleep aid?
However, what seems like falling asleep is actually something closer to passing out, because sedation is not like natural sleep but rather a light form of anesthesia. Even more critical than the artificial sedating influence are the effects of alcohol on your entire night of sleep. As your body metabolizes the alcohol, your sleep becomes lighter and more fragmented. Like sleeping pills alcohol is disrupting your sleep cycle.
This process happens especially during the second half of the night and is also referred to as the rebound effect. Your sleep is often interrupted by frequent brief awakenings and is therefore not at all restorative. The problem is that you don’t notice these awakenings and may fail to link your next-day sleepiness to your alcohol consumption the night before. You feel unrefreshed when waking up from a night of drugged sleep with alcohol, sometimes being so miserable as if you hadn’t slept at all.
Also keep in mind that you can quickly build a tolerance for the sedative effects of alcohol, and you may end up drinking even more to have the same sleep-inducing effects.
The effect of alcohol on your brain during sleep
Another reason why alcohol can mess up your sleep is that it powerfully suppresses your REM sleep. REM sleep is the sleep stage during which your brain is more active, and you sometimes experience intense dreams. During the metabolization process of alcohol, your body produces the two chemicals called aldehydes and ketones which can block your brain’s ability to generate REM sleep. In other words, when you drink at night, you deprive yourself of dream sleep, and you are more likely to wake early in the morning and not be able to fall back to sleep.
The problem with the lack of REM sleep is not so much that you are missing out on dreams. More critical is the deficit of highly important mental restoration processes, including memory and emotional processing which occur during REM sleep. During this phase of sleep, your brain makes the neural connections which are vital to your mental recovery and emotional well-being. Not getting enough REM sleep radically reduces your ability to cope with stress or any kind of emotional challenge.
Also, the REM sleep stage stimulates the areas of your brain that are essential in retaining memories. For example, if you are learning a new language, REM sleep helps you to exercise the necessary information processing required for developing grammatical rules. It is during your sleep when you start to synthesize large sets of related facts into an interconnected whole.
But keep in mind that your memory processing is not done in one night. It is not sufficient to only have one good night of sleep with adequate amounts of REM sleep after learning. Your memory remains vulnerable to any sleep disruption for several nights after the learning. Therefore developing a consistent healthy sleep schedule is key for successful learning and memorizing.
What are other sleep disruptions associated with alcohol consumption?
- More frequent need to go to the bathroom, especially during the second half of the night
- Increased risk for parasomnias including sleep-related eating disorders, sleepwalking, nightmares, and sleep paralysis
- Greater risk for snoring. Alcohol can stop you breathing well because it relaxes the muscles in the head, neck, and throat preventing air flowing smoothly.
- Alcohol can compound existing sleep disorders or trigger new ones, including insomnia and obstructive sleep apnea
How to deal with alcohol before bedtime?
In his fascinating book Why We Sleep Matthew Walker boils it down to the following recommendation: “It is hard not to sound puritanical, but the evidence is so strong regarding alcohol’s harmful effects on sleep that to do otherwise would be doing you, and the science, a disservice. … Nightly alcohol will disrupt your sleep, and the annoying advice of abstinence is the best, and most honest, I can offer.”
However, total abstinence might not always be possible or wanted. When you drink at night try to eat at least some protein-rich and fatty food beforehand. Never drink on an empty stomach. Eating a hearty meal slows the absorption of alcohol into your system.
Same with water; drinking water helps to slow the absorption of alcohol into the bloodstream and assists with dehydration. Use the “two for one” rule: two glasses of water for every alcoholic drink. However, keep in mind that water won’t make you any less drunk or protect your liver.
And – always abstain if you’re taking sleeping pills. As mentioned drinking alcohol makes it harder for you to breathe normally. Sleep medication works the same way, which means you’re suppressing your ability to breathe even more. Hence, alcohol compounds the effects of sleeping pills, which can become quite dangerous.