Exploring the Complex Effects of Alcohol on the Brain: From Short-Term Impairment to Long-Term Consequences

Alcohol consumption has become a socially acceptable activity that has been intertwined with people’s daily life since the Neolithic period. Even though light-to-moderate drinking may have health benefits, long-term excessive drinking can wreak havoc on the brain. The question is when does the line between moderate and heavy drinking begin to blur and how much is too much for alcohol to start affecting the brain?

The National Institute on Alcohol Abuse and Alcoholism (NIAAA) defines binge drinking as a person who consumes alcohol to a point where it brings their blood alcohol concentration (BAC) to 0.08 g/dL or higher. That would be equivalent to five or more drinks for men and four or more for women within two hours of the same occasion. Alcohol reaches crucial areas of the brain, including the cerebral cortex, frontal lobe, hippocampus, hypothalamus, and cerebellum, impairing a person’s balance, judgment, speech, and memory, and forces the brain to work harder. Increasing BAC levels over time might be enough to create long-term effects on the brain.

The amount of alcohol someone drinks, how often they drink, at what age they started drinking, family history, gender, genetics, and health status are some of the most common triggers that determine how alcohol affects the brain.

Alcohol can affect the brain in many ways. It skews a person’s senses, and at first, they tend to become more confident as alcohol acts as a depressant in the cerebral cortex (which controls inhibition) and reaches no-go receptors in the brain, inducing the release of dopamine – the chemical responsible for pleasure. However, depending on the amount of alcohol consumed, a person may then experience slurred speech, waddling, impaired vision, confusion, and memory issues, putting themselves in danger in extreme cases.

An alcohol-induced blackout is another way alcohol affects the brain. If a person doesn’t remember details of a conversation they had with you during a night of drinks, or barely recalls things they did or said, there is a big chance they had a blackout. Alcohol-induced blackouts happen when alcohol prevents the consolidation of memories in the hippocampus, and the individual’s drinking pattern impairs the transfer of short-term memory to long-term memory.

There is no shortage of literature exposing the long-term effects of alcohol on the brain, including mental health issues such as anxiety and depression, and alcohol use disorder. Long-term heavy drinking can trigger these issues and lead to other severe brain disorders. As alcohol hinders communication pathways, compromising brain functioning, researchers have found that long-term heavy drinking leads to changes in the neurons (including their size), causing “brain shrinkage.” Studies have shown that shrinkage in the brain was directly related to the amount of alcohol someone ingested. The most extreme case of thiamine (vitamin B1) deficiency caused by chronic alcohol consumption can cause a severe brain condition called Wernicke–Korsakoff syndrome. Chronic liver disease, or cirrhosis, is another example of severe brain damage caused by alcoholism.

In the United States, data from the 2019 National Survey on Drug Use and Health (NSDUH) showed that over 85 percent of adults aged 18 and older admitted to drinking alcohol at some point in their life, with more than 25 percent engaging in binge drinking. In light of these statistics, it is essential to consider the impact of alcohol on the brain and moderate consumption to prevent long-term damage.

As Aaron M. White, an assistant professor from the Department of Psychiatry at Duke University Medical Center, said, “Drinking too much too quickly on a single occasion, or over time, can have a range of health consequences, including accidents and injuries, sexually transmitted infections, liver