How does alcohol affect the brain?
Alcohol affects your body quickly once ingested. It is absorbed through the lining of your stomach into your bloodstream, which then diffuses it into your body tissues. Alcohol reaches your brain in only five minutes, with immediate effects appearing within 10 minutes.
What about your brain on alcohol?
Alcohol begins affecting a person's brain as soon as it enters the bloodstream. In a healthy person, the liver quickly filters alcohol, helping the body get rid of the substance. However, when a person drinks in excess, the liver cannot filter the alcohol fast enough, and this triggers immediate changes in the brain.
Over time, excessive alcohol consumption can damage both the brain and liver, causing lasting damage to the body.
Excessive alcohol consumption can have long-lasting effects on chemical messengers in the brain, decreasing their effectiveness or even mimicking them. Alcohol also destroys brain cells and shrinks brain tissue. Some people with a history of excessive alcohol use develop nutritional deficiencies that further damage brain function.
The precise symptoms of alcohol-related brain damage depend on a person's overall health, how much they drink, and how well their baseline liver functions, among other factors.
Long-term effects
Over time, alcohol abuse can cause permanent brain damage. One form of alcohol-related brain damage is Korsakoff syndrome. Korsakoff syndrome often appears after an episode of Wernicke's encephalopathy, which is acute alcohol-related brain dysfunction.
The two conditions, together called Wernicke-Korsakoff syndrome, happen in people who are severely deficient in thiamine (Vitamin B1). Alcohol abuse makes it more difficult for the body to absorb this nutrient, other causes such as severe eating disorders, cancer, AIDS, and conditions that affect the body's ability to absorb nutrients, may also cause Wernicke-Korsakoff syndrome.
Some symptoms of Wernicke's encephalopathy include:
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Confusion and disorientation that continue well beyond the period of drunkenness
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Malnourishment that may cause significant weight loss
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Trouble moving the eyes or strange and jerky eye movements
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Poor balance
Following Wernicke's encephalopathy, the person may develop signs of Korsakoff syndrome. This disorder is a type of dementia. People suffering with this condition may experience:
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Memory problems, in particular, difficulties forming new memories
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Poor judgment
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Decreased planning and organizational skills
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Mood and personality changes
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Hallucinations
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The progressively worsening cognitive decline that may affect every area of functioning, including speech, vision, and bowel and bladder function
Vitamin supplements and complete abstinence from alcohol may reverse symptoms of Wernicke-Korsakoff syndrome within the first 2 years after stopping alcohol consumption.
Ethanol in alcohol
The ethanol in alcohol acts like a poison. When the liver is not able to filter this poison quickly enough, a person can develop signs of alcohol poisoning or alcohol overdose. An overdose of alcohol affects the brain's ability to sustain basic life functions. Symptoms include:
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Vomiting
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Seizures
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Slow heart rate
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Difficulty staying awake
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Fainting
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Low body temperature
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Reduced gag reflex, which can increase the risk of choking if a person vomits
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Clammy skin
An untreated alcohol overdose can be fatal. Severe alcohol overdose may cause permanent brain damage even if the person survives.
The higher a person's blood alcohol concentration, the higher their risk of alcohol overdose. The heavy consumption of high-alcohol drinks is more likely to cause alcohol poisoning.
Alcohol consumption recommendations
It is recommended to limit alcohol intake to 2 drinks or less per day for men and 1 drink or less per day for women.
All in all
Alcohol has an immediate effect on the brain and may cause damage if it is consumed heavily on a regular basis. Excessive alcohol consumption can also affect quality of life. Ensure your alcohol intake is within the recommended limits to reduce alcohol-related disease or brain damage.
Medically reviewed by Ashwini Nair, MB BCh BAO.
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References:
- Alcohol Questions and Answers | CDC. Published February 16, 2021. Accessed April 1, 2022. https://www.cdc.gov/alcohol/faqs.htm
- Drinking too much alcohol can harm your health. Learn the facts | CDC. Published December 29, 2021. Accessed April 1, 2022. https://www.cdc.gov/alcohol/fact-sheets/alcohol-use.htm
- Wernicke-Korsakoff Syndrome: Background, Etiology, Pathophysiology. Published online February 18, 2022. Accessed April 1, 2022. https://emedicine.medscape.com/article/288379-overview
- Facts about moderate drinking | CDC. Published February 19, 2021. Accessed April 1, 2022. https://www.cdc.gov/alcohol/fact-sheets/moderate-drinking.htm
