Alcohol (also known formally as
ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a ...
), found in
alcoholic beverages, can exacerbate sleep disturbances. During
abstinence, sleep disruption is one of the greatest predictors of
relapse
In internal medicine, relapse or recidivism is a recurrence of a past (typically medical) condition. For example, multiple sclerosis and malaria often exhibit peaks of activity and sometimes very long periods of dormancy, followed by relapse or ...
.
[Feige, B., Scaal, S., Hornyak, M., Gann, H., Riemann, D. Sleep electroencephalographic spectral power after withdrawal from alcohol in alcohol-dependent patients. ALcoholism: Clinical and Experimental Research. 2007 Jan; 31 (1): 19-27.]
Moderate alcohol consumption and sleep disruptions
Moderate alcohol consumption 30–60 minutes before bedtime results in disruptions in sleep maintenance and sleep architecture that are mediated by
blood alcohol level
Blood alcohol content (BAC), also called blood alcohol concentration or blood alcohol level, is a measurement of alcohol intoxication used for legal or medical purposes; it is expressed as mass of alcohol per volume or mass of blood. For example ...
s.
[Roehrs, T., and Roth, T. Sleep, sleepiness, and alcohol use. Alcohol Research & Health. 2001; 25(2):101-109.] Disruptions in sleep maintenance are most marked once alcohol has been completely
metabolized
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
from the body. Under conditions of moderate alcohol consumption where blood alcohol levels average 0.06–0.08% and decrease 0.01–0.02% per hour, an alcohol clearance rate of 4–5 hours would coincide with disruptions in sleep maintenance in the second half of an 8-hour sleep episode.
In terms of sleep architecture, moderate doses of alcohol facilitate "rebounds" in
rapid eye movement (REM) and
stage 1 sleep; following suppression in REM and stage 1 sleep in the first half of an 8-hour sleep episode, REM and stage 1 sleep increase well beyond baseline in the second half. Moderate doses of alcohol also increase
slow wave sleep
Slow-wave sleep (SWS), often referred to as deep sleep, consists of stage three of non-rapid eye movement sleep. It usually lasts between 70 and 90 minutes and takes place during the first hours of the night. Initially, SWS consisted of both S ...
(SWS) in the first half of an 8-hour sleep episode.
Enhancements in REM sleep and SWS following moderate alcohol consumption are mediated by reductions in
glutamatergic
Glutamatergic means "related to glutamate". A glutamatergic agent (or drug) is a chemical that directly modulates the excitatory amino acid (glutamate/aspartate) system in the body or brain. Examples include excitatory amino acid receptor agonis ...
activity by
adenosine in the
central nervous system
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all p ...
.
In addition, tolerance to changes in sleep maintenance and sleep architecture develops within 3 days of alcohol consumption before bedtime.
Alcohol consumption and sleep improvements
Low doses of alcohol (one 360.0 ml (13 imp fl oz; 12 US fl oz)
beer
Beer is one of the oldest and the most widely consumed type of alcoholic drink in the world, and the third most popular drink overall after water and tea. It is produced by the brewing and fermentation of starches, mainly derived from ce ...
) are sleep-promoting by increasing total sleep time and reducing awakenings during the night. The sleep-promoting benefits of alcohol
dissipate
In thermodynamics, dissipation is the result of an irreversible process that takes place in homogeneous thermodynamic systems. In a dissipative process, energy (internal, bulk flow kinetic, or system potential) transforms from an initial form to ...
at moderate and higher doses of alcohol (two 12 oz. beers and three 12 oz. beers, respectively). Previous experience with alcohol also determines whether or not alcohol is a "sleep promoter" or "sleep disrupter." Under free-choice conditions, in which subjects chose between drinking alcohol or water, inexperienced drinkers were sedated while experienced drinkers were stimulated following alcohol consumption. In
insomnia
Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, ...
cs, moderate doses of alcohol improve sleep maintenance.
Alcohol consumption and fatigue
Sleepiness influences the severity of alcohol consumption. Conditions of
sleep deprivation encourage more episodes of alcohol consumption.
Increased alcohol consumption during the winter months for Northern climate residents is attributed to escalations in fatigue.
Alcohol abstinence and sleep disruptions
Sleep and
hormonal
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required f ...
disruptions following withdrawal from chronic alcohol consumption are the greatest predictors of relapse.
During abstinence, recovering alcoholics have attenuated
melatonin secretion in the beginning of a sleep episode, resulting in prolonged sleep latencies.
[Kühlwein, E., Hauger, R.L., Irwin, M.R. Abnormal nocturnal melatonin secretion and disordered sleep in abstinent alcoholics. Biol Psychiatry. 2003; 54: 1437-1443.] Escalations in
cortisol and
core body temperature
Normal human body-temperature (normothermia, euthermia) is the typical temperature range found in humans. The normal human body temperature range is typically stated as .
Human body temperature varies. It depends on sex, age, time of day, exert ...
s during the sleep period contribute to poor sleep maintenance.
[Danel, T., Libersa, C., Touitou, Y. The effect of alcohol consumption on the circadian control of human core body temperature is time dependent. Am J Physiol Regulatory Integrative Comp Physiol. 2001; 281: R52-R55.] Abstinent alcoholics tend to have lighter, more fragmented sleep than normal control subjects. Research indicates that it may take as long as one to two years for sleep to return to normal in abstinent alcoholics and that for some it may never return to normal.
See also
*
Nightcap (beverage)
A nightcap is a drink taken shortly before bedtime. For example, a small alcoholic drink or glass of warm milk can supposedly promote a good night's sleep.Stone, Barbara"Sleep and low doses of alcohol" '' Electroencephalography and Clinical Neur ...
*
Short-term effects of alcohol consumption#Sleep
*
Sleep induction#Alcohol
References
{{Psychoactive substance use
Ethanol
Sleep