Alcohol and Sleep

by Cameron Craw, ND

Over the years, I have heard many people tell me that evening alcohol use helps them sleep better. Among other things, alcohol functions as a sedative. This means it modifies neurotransmitter activity in the brain resulting in an overall reduction in various forms of brain activity. This helps explain the assertion by many that alcohol helps with sleep. If sleep is hard to achieve because you find that your mind is too active to "shut down" when you hop into bed at night, then utilizing a relaxing beverage to help you calm your active mind and achieve a more restful nights sleep is a no-brainer, right? Yes, as a sedative, alcohol is a certain kind of "no-brainer," but not necessarily the good kind. Though alcohol has been shown to shorten the time needed to fall asleep (Roehrs, 1999; Williams, 1983), research suggests that it does not actually support quality sleep. Let's look at what we know.

Melatonin

Melatonin is commonly known as the master sleep hormone. It is a key player in maintaining our daily sleep and wake cycle. Melatonin is released by a small gland near the center of your brain each evening as your light exposure for the day declines (assuming you aren't staring at your mobile device or computer late at night!). Interestingly, melatonin seems to be most important for sleep onset and less critical for sleep maintenance. It is as if melatonin, when it bathes your brain each evening, serves as the spark plug that ignites the combustion engine of sleep—setting mechanisms in motion that propel the complex neurochemistry of sleep on its way through the wee hours of the night. After this initial spark, melatonin's various functions are less clear. It appears to be at its highest level in the early morning hours before sunrise.

 In a small study involving 29 young adults, moderate alcohol intake (roughly two to three glasses of wine) one hour before bedtime reduced melatonin levels by 15–19% in the following 2–3 hours (Rupp, 2007). This suggests that having a glass or two of wine with dinner will have a negative effect on your melatonin output come bedtime. This is likely bad news as low levels of melatonin are associated with Alzheimer's disease, Parkinson's disease, and many other undesirable neurological conditions (Talbot 2023).

The Rebound Effect

Once alcohol is fully metabolized by your body, its function as a sedative wears off and what is known as a "rebound effect" occurs. The mechanism of this rebound effect is still not fully understood but its outcome is well documented (Williams, 1972; Stein, 2005). Simply put, where the alcohol "helped" to promote deep sleep for the first part of the night, now its absence results in disrupted and restless sleep in the latter half of the night. The net effect is lower quality total sleep due to a disruption of your natural, cyclical, sleep rhythm. This disruption results in things like poorer long-term memory consolidation (poor learning), reduced ability to focus (distractibility), and a greater propensity towards irritability and depression.

Sleep Apnea

Sleep apnea is a disorder where breathing repeatedly stops and starts during sleep. Sleep apnea can be "obstructive" in nature, due to a physical airway obstruction (such as airway blockage by tongue or throat tissue). Sleep apnea can also be "central" (brain based) in nature, due to reduced respiratory drive (the automatic breathing reflex that prevents us from having to consciously decide to breathe each moment). Sleep apnea can be very disruptive to sleep as it often results in waking dozens of times each night in an effort by the body to reinitiate breathing. Often, people with sleep apnea report that they don't remember these waking events, but they find that they feel unrested and fatigued each morning.

A 2018 meta-analysis (think of this as a compare and contrast assessment of many related scientific studies) of 21 studies concluded that moderate alcohol consumption increased risk of sleep apnea by 25% (Simou, 2018). I don't think we should find this conclusion surprising. We know that alcohol consumption can contribute to weight gain (a risk factor for obstructive sleep apnea). We also know that alcohol consumption leads to poor muscular coordination in the form of things like slurred speech. In the case of sleep apnea, the muscles of throat and mouth are affected, leading to a narrowing of the airway. On top of this, recall that alcohol has a sedative effects on brain function—including the brain stem, which is responsible for things like heart rhythm and breathing. The single most important life-threatening complication of severe alcohol intoxication is respiratory depression (slowed or absent breathing). Of course, one does not need to consume a life threatening amount of alcohol to achieve a milder depression of respiratory drive throughout the night leading to extended delays between breathing and decreased blood oxygen levels.

Conclusion

Alcohol is a tricky substance. Like many sleep aids, alcohol makes you feel like you are getting better sleep because it drives your brain into a less active state, but quality sleep is more complicated than simply achieving reduced brain activity. No, sleep is not just the nightly process of going unconscious. It is a series of synchronized, rhythmic melodies that the brain hums each night in service of a vast collection of restorative and integrative physiologic processes. The best measure of whether or not you are sleeping well is not necessarily how fast you fall asleep at night or how many times you remember waking up during the night (though these may be helpful data points). The best measure is how rested you feel when you wake up, and whether the gains you have acquired from your sleep can carry you throughout your day.

References

 Roehrs T, Papineau K, Rosenthal L, Roth T. Ethanol as a hypnotic in insomniacs: self administration and effects on sleep and mood. Neuropsychopharmacology. 1999;20(3):279-286. doi:10.1016/ S0893-133X(98)00068-2 

Rupp TL, Acebo C, Carskadon MA. Evening alcohol suppresses salivary melatonin in young adults. Chronobiol Int. 2007;24(3):463-470. doi:10.1080/07420520701420675 

Simou E, Britton J, Leonardi-Bee J. Alcohol and the risk of sleep apnoea: a systematic review and metaanalysis. Sleep Med. 2018;42:38-46. doi:10.1016/j.sleep.2017.12.005 

Stein MD, Friedmann PD. Disturbed sleep and its relationship to alcohol use. Subst Abus. 2005;26(1):1-13. doi:10.1300/j465v26n01_01 

Talbot NC, Luther PM, Spillers NJ, et al. Neuroprotective Potential of Melatonin: Evaluating Therapeutic Efficacy in Alzheimer's and Parkinson's Diseases. Cureus. 2023;15(12):e50948. Published 2023 Dec 22. doi:10.7759/cureus.50948 

Williams DL, MacLean AW, Cairns J. Dose-response effects of ethanol on the sleep of young women. J Stud Alcohol. 1983;44(3):515-523. doi:10.15288/jsa.1983.44.515

Cameron Craw, ND, is Hive Mind Medicine’s resident for the 2023/24 academic cycle. He received his doctorate in Naturopathic medicine at the National University of Natural Medicine (NUNM) in 2023. He is currently completing a master’s degree in acupuncture. Prior to graduation, Dr. Craw spent three terms on Dr. Sandberg-Lewis's Gastrointestinal Mentor Rotation and is now helping Dr. SS-L supervise the shift.

Hive Mind Medicine blog posts are for educational purposes only and are not intended as medical advice. Please consult with your health care practitioner for personalized guidance.