Public-health experts warn there’s no safe dose of alcohol. But who listens? Alcohol abuse can spiral into addiction and cause serious harm, especially to the brain.
Short-Term Effects of Alcohol
Speech
The American Centers for Addiction Treatment say people typically struggle to string words together when their blood alcohol concentration (BAC) reaches 0.1 percent.
Alcohol alters the balance between two key neurotransmitters: glutamate, which excites neurons, and gamma-aminobutyric acid (GABA), which inhibits them. When GABA levels rise and glutamate levels fall, neurons fire more slowly and every action takes longer.
If that imbalance affects areas responsible for motor control, it disrupts movements of the tongue and facial muscles and makes speech slurred and difficult.
Body Imbalance
Interference with motor neuron function can affect not only speech but also walking and coordination. The brain controls movement and the visual-spatial processing that keeps us upright, so when alcohol interferes, balance suffers.
This effect is typically seen when BAC reaches 0.18–0.25. At that level, drinking impacts nearly every part of the brain, according to IFLScience.
Memory
People often call alcohol-induced memory loss a “blackout.” Someone might arrive at a new place with no memory of how they got there, or find themselves in dangerous situations they don’t remember.
Blackouts are linked to alcohol’s effects on the hippocampus, a brain region essential for forming new memories.
Inhibitions
Alcohol clouds clear thinking and lowers inhibitions, leading people to say and do things they wouldn’t consider when sober.
That happens because alcohol impairs the prefrontal cortex, the area that handles reasoning, judgment, and other higher cognitive skills—at least when you’re sober.
Long-Term Effects of Alcohol Consumption
When drinking becomes excessive and chronic, it can cause life-threatening brain damage.
Addiction
Alcohol can be addictive. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) describes three main mechanisms that contribute to alcohol use disorders.
- Alcohol activates the brain’s dopamine-driven reward system, which can push some people to drink more.
- Drinking can become habitual when the decision to drink slips out of conscious control, making it hard to stop.
- Alcohol temporarily blunts pain and negative emotions by reducing activity in the amygdala and lowering stress. When that effect fades, people may drink more to chase the same relief.
Wernicke’s Encephalopathy
People who drink heavily are prone to Wernicke’s encephalopathy, a condition caused by a deficiency of vitamin B1 (thiamine).
Key symptoms include changes in mental status, walking difficulties (including the loss of the ability to walk), and eye movement disorders. Without treatment, Wernicke’s encephalopathy can be fatal. In about 85 percent of untreated cases, a chronic complication called Korsakoff syndrome develops.
Korsakoff Syndrome
Korsakoff syndrome often follows Wernicke’s encephalopathy; together the conditions are called Wernicke-Korsakoff syndrome.
The primary symptom is short-term memory loss, though some people also have problems with long-term memory. Many people with Korsakoff syndrome are unaware they have it and can continue to socialize, work, and hold conversations.
Over time, these individuals often develop blood pressure and cardiovascular problems and face a higher risk of premature death.
Can Brain Damage Caused by Alcohol Be Reversed?
The brain can recover if people stop drinking. A recent study found that participants who had abused alcohol for years showed restoration of cortical thickness to levels similar to non-drinkers after about 7.3 months of abstinence.
Another study found that just 18 days of sobriety was enough to improve cognitive performance.
