How Alcohol Hurts Sleep Quality

There is a common misbelief that a nightcap or certain alcoholic drinks (looking at you red wine) helps you sleep. The truth is, it can make you feel tired or mentally foggy and significantly disrupt your sleep. 


Alcohol is a sneaky sleep disrupter that can trick you into thinking you are getting a good night's sleep but can actually reduce the quality of your sleep and leave you feeling tired the next day.


Alcohol is a central nervous system depressant. In layman’s terms – it’s a downer. This causes your brain to slow down, making it difficult to think clearly, remember details, and alters your behaviors. This is why with a couple of drinks, you can start to feel drowsy. However, there are also physical changes at play that can make it difficult to sleep, trigger insomnia or even exacerbate sleep apnea symptoms. This may sound confusing – how does something that makes me feel sleepy negatively impact my sleep?


I get it. But the research has shown that this is, in fact, true. For example, let’s say you have a gin and tonic in the evening. The alcohol within the gin travels down to your stomach and small intestine. Here is absorbed into your bloodstream. Your liver and the enzymes within will work tirelessly to try to metabolize the alcohol. Still, it is a relatively slow process, so the alcohol continues to circulate through your body. This means that if you had your last drink at 7 pm, the alcohol will be in your bloodstream throughout the night and even into the morning.



The National Sleep Foundation says this is because of the production of adenosine, a chemical in the brain that can induce sleep. Adenosine increases when drinking but quickly wears off, so you wake up. Alcohol also tampers with our sleep hormone melatonin. Melatonin is needed to regulate our sleep cycles, but according to a 2007 study, just one drink before bed can decreases melatonin by up to 19%!


To understand how it impacts your sleep, you need to be familiar with the different sleep stages. You can check out our blog post on Sleep Stages: What They Are and How Much You Need here.



All our sleep cycles are essential, and we need a good amount of each to be considered a night of restful sleep. Alcohol significantly disrupts the sleep cycle known as REM. When alcohol's sedative effects kick it, it can cause you to fall asleep quickly and promptly get into a deep sleep stage (stage 3). Though this may sound good, it actually creates an imbalance between REM sleep and slow-wave sleep. As a result, it decreases sleep duration, creates more sleep disruptions, and causes sleep quality to decline. 



According to Irshaad Ebrahim, the medical director at The London Sleep Centre, “the immediate and short-term impact of alcohol is to reduce the time it takes to fall asleep, and this effect on the first half of sleep may be partly the reason some people with insomnia use alcohol as a sleep aid. However, this is offset by having more disrupted sleep in the second half of the night”. This is often called the rebound effect. While it helps you fall asleep faster at first, as soon as it leaves your body, it will have the opposite effect. This is why sometimes people who have a couple of drinks may fall asleep then find themselves waking up continuously throughout the night.



One of the first studies that looked at the effects of alcohol on sleep was conducted in 1939. 



The study found that when a person consumed an alcoholic drink one hour before bed, their bodily temperature dropped during the first part of their sleep. This is what happens typically. However, during the second half of the night, when sleep disturbances occur, their body temperature increased.



Alcohol can also make sleep apnea worse. Sleep apnea is when a person temporarily stops breathing during sleep, causing sleep disruptions. There are two types: obstructive sleep apnea (OSA) and central sleep apnea (CSA). OSA is caused by physical blockages at the back of the throat, and CSA occurs when the brain stops signaling to the muscles that control breathing. One study found that consuming alcohol increased the risk of sleep apnea by 25%. Additionally, because alcohol disrupts REM sleep, it can increase the likelihood of sleepwalking, sleep talking, and memory issues.



In some cases, those who regularly have a nightcap or two before bed can experience insomnia. They may then feel inclined to drink more to make them feel sleepy, but this doesn’t work as intended. So, the next day they feel tired and have trouble getting through the day. Consequently, they reach for coffee after coffee to keep themselves awake and alert. Though this can help them resist the urge to take a nap under the desk, the high caffeine intake can make them feel awake in the evening. They may then again reach for an alcoholic drink to essentially self-medicate and help them fall asleep. It’s a vicious cycle with adverse physical and mental consequences. Ebrahim told WebMD, “Alcohol should not be used as a sleep aid, the regular use of alcohol as a sleep aid may result in alcohol dependence.”



Nightcaps aren’t the only type of drinking that will disrupt sleep. Binge drinking is especially harmful to your sleep. This type of drinking can happen at any age, but it is more common in people in their twenties. Binge drinking is classified as drinking an excessive amount of alcohol in a shorter span of time, which causes your blood alcohol level to sky-rocket, reaching a level of 0.08% or higher.  Research has found that people who engage in binge drinking once a week are more likely to have sleep difficulties.



Alcohol and Sleep


If you enjoy a glass of wine with dinner or like to have a pint while watching football on Sunday nights, you don’t have to give it up completely. But it is important to note that even small amounts of alcohol can impact your sleep.


In 2018 a study compared the sleep quality of people who consumed different amounts of alcohol. Those who had a low amount (less than two servings for men, one serving for women) experienced a reduction in sleep quality by 9.3%. Those who had a moderate amount (two servings a day for men, one serving a day for women) decreased sleep quality by 24%. As you can imagine, those who consumed a high amount of alcohol (more than two servings a day for men and more than one serving for women) had a sleep quality reduction of 39.2%!



It is clear from the results of this study that the fewer drinks you have, the better sleep you will get. In addition to the quantity of alcohol you consume, you should also factor in timing. For example, to reduce sleep disruptions, it is best to stop drinking at least four hours before bed. This will give your body more time to metabolize the alcohol.   



It doesn’t matter what type of alcohol you have. Wine, liquor, beer – when it comes to sleep, it’s all the same. That said, you may find you experience more drowsiness with certain beverages than others, but after you fall asleep, the same disruptions can occur.


If you have been using alcohol to help you fall asleep but have fallen into the vicious cycle of self-medicating with alcohol and caffeine, you should put a stop to it. Scott Krakower, DO, says, “people who drink alcohol often think their sleep is improved, but it's not.” It essentially tricks you into thinking you are getting a night of better sleep, so the behavior continues. Stopping the cycle may initially be challenging but look to natural remedies and improving your sleep hygiene. If there are other issues at play, like sleep apnea, you should speak to your health care provider.



A comfortable sleeping environment and a supportive pillow like buckwheat pillow or a millet pillow will make it easier to fall asleep. If you don’t have a comfortable bed and wake up in pain, you won’t sleep well. Temperature matters too! When we sleep, our body’s temperature declines, so by lowering the temperature of your bedroom, you can help trigger sleep.



If your current wind down routine involves a glass of pinot grigio and a few episodes of your favorite Netflix series, try something new that will benefit your sleep. Put on some soothing music and meditate. Dim the lights, light some candles, and sit on a meditation pillow. Allow your mind to be quiet, and if needed, turn on a guided bedtime meditation for at least 10 minutes.  



REM sleep is critical to your health and wellness. Without it, you will feel foggy-headed, lethargic, and have memory issues. So don’t let the alcohol fool you – it’s not actually helping you sleep. In fact, it is hurting your sleep quality.

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