Alcohol and the human body

Human brain

Central Nervous System - The Brain

The brain is made up of more than 100 billion neurons. Each makes tens of thousands of connections throughout our bodies. Researchers used to think that most brain development took place during the first few years of life, but new findings have shown that during the teen years and into a person’s twenties, important changes are taking place. For example, parts of the brain that help teens make decisions and control their impulses are still forming. In fact, many characteristics of adolescence, such as mood swings, may be, in part, a result of brain development. Too much alcohol can damage or even kill neurons, perhaps changing the development of those parts of the teenage brain that are still forming.

The brain is protected by the blood-brain barrier, which prevents or slows the passage of some drugs and other harmful substances from the blood into the central nervous system. Alcohol, however, is able to penetrate the brain because it can cross the blood-brain barrier.

Because of the way different parts of the brain respond to alcohol, teens may engage in behaviors that are not good for them. For example, drinking alcohol can lead to making bad decisions. Because the prefrontal cortex is not mature, too much alcohol can harm a teen’s ability to reason and weigh choices. Instead, teens may do something simply because they think it may be fun or feel good regardless of later consequences. Because connections between the prefrontal cortex and the ventral striatum are still maturing, alcohol can affect those connections. As a result, teens may take risks that they would not usually take, such as drinking and driving or having unprotected sex.

Next: Parts of the Brain