Alcohol is a depressant to the Central Nervous System that causes the brain to slow down. However, that doesn’t mean that it helps your brain get a good night’s rest. It is a common perception that alcohol will help you fall asleep and keep you asleep due to its sedative effects that can help you relax and cause drowsiness. The excuse of “better sleep” is one reason alcohol is such a common addiction. (1)
Normal Stages of Sleep:
- NREM:
- the transition between wakefulness and sleep
- Body shuts down
- Heartbeat, breathing, and eye movement will slow down
- Muscles relax
- Brain activity decreases
- “light sleep stage”
- NREM:
- Heartbeat and breathing continues to slow down into deeper sleep
- Body temperature decreases
- Eyes will become still
- Longest sleep stage
- NREM:
- Heartbeat, breathing rates, and brain activity reach the lowest levels
- Eye movements cease and the muscles are relaxed
- Slow-wave sleep
- REM:
- After 90 minutes of falling asleep
- Active eye movements
- Breathing rate and heartbeat are faster
- Dreaming occurs
- Memory consolidation
(2)
Alcohol reduces the duration of the REM stage and causes sleep disruptions. REM sleep is important as it maintains mental and brain health, the most restorative stage, processing of the day’s events, and the cleaning of neuro-toxins. This is helpful to reduce the chances of developing Alzheimer’s and Parkinson’s. Once the individual has consumed the alcohol it is absorbed into the bloodstream from the stomach and small intestine. The enzyme in the liver will then metabolize the alcohol which causes an increase in waking up, trips to the bathroom, and poor quality of sleep. The increase of sleep disruptions will result in a feeling of tiredness the next day. In order to fall asleep, the individual may fall into a vicious cycle of drinking to get “a good night’s sleep”, fall asleep faster, building a tolerance, soon developing an addiction, and destroying the individual’s circadian rhythm. It is suggested to not drink 4 hours before bed in order to avoid sleep disturbances caused by metabolizing. (3) (4)
(5)
An increase of alpha and delta brain waves is found during sleep after consuming alcohol. The increased activity of these two waves is correlated to the feeling of fatigue, depression, and cause of sleep disorders. Delta activity helps with memory processing and consolidation from the day’s events. Delta waves are the slowest waves and are most commonly found in babies, children, brain injuries, individuals with learning disabilities, and severe ADHD (6), Normal alpha activity occurs during rest not sleep. They help with creativity, lower feelings of anxiety and depression, increases pain tolerance, and boosts stress resilience. (7)
Below is a diagram showing the difference of the Theta and Delta brain waves in the frontal and parietal lobes of individuals who were exposed and not exposed to alcohol before sleeping. Theta waves are normally seen during meditation, prayer, and sharp focus with the benefits of increased creativity, daydreaming, and storing memories, sensations, and emotions. (8)
(9)
Interestlingy, it is found that the elder population are more prone to have alcohol relate sleep disorder due to higher levels of alcohol found in their blood and brain compared to younger adults when consuming the same amount of alcohol content. (1)
Resources:
- https://www.webmd.com/sleep-disorders/drug-alcohol-related
- https://www.sleepfoundation.org/nutrition/alcohol-and-sleep
- https://desertcoverecovery.com/blog/alcohols-impact-on-sleep/
- https://clearliferecovery.com/rehab-blog/alcohol-rehab-costa-mesa-california-explores-the-impact-of-alcohol-on-sleep/
- https://choosemuse.com/blog/a-deep-dive-into-brainwaves-brainwave-frequencies-explained-2/
- https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/brain-waves
- https://daveasprey.com/alpha-brain-waves-lower-stress/
- https://nhahealth.com/brainwaves-the-language/
- https://www.researchgate.net/figure/Delta-and-theta-power-during-slow-wave-sleep-in-the-frontal-and-parietal-cortex-after_fig1_324041698
