“Alcohol kills brain cells.”

The persistent idea that alcohol directly kills brain cells is a widespread misconception, often perpetuated by the stark, observable effects of heavy drinking. This myth may have roots in early, oversimplified scientific observations, such as applying concentrated alcohol to brain cells in a lab setting, which does not accurately reflect how the body processes alcohol. The noticeable impairments in judgment, coordination, and memory that occur during intoxication likely contributed to the belief, as people might feel as though their brain function is being permanently "killed off."

However, scientific evidence indicates that alcohol does not typically cause neurons, the main brain cells, to die outright. Instead, alcohol is a neurotoxin that primarily interferes with the intricate communication network (Review) within the brain. It disrupts the delicate dendrites, which are the branch-like extensions of neurons responsible for receiving signals. This interference impairs the brain cells' ability to send and receive messages effectively, essentially "fuzzing up the signal" rather than cutting the lines entirely.

While brain cells are not directly killed, the cumulative impact of excessive and chronic alcohol consumption is far from harmless. This disruption of neural connections can lead to significant brain damage over time, including measurable brain shrinkage, or atrophy, particularly in areas vital for memory, learning, and decision-making like the hippocampus and frontal lobes. Furthermore, heavy drinking can lead to conditions such as Wernicke-Korsakoff syndrome, a severe neurological disorder caused by a thiamine deficiency often seen in chronic alcoholics, which does result in the loss of neurons and profound memory impairment. So, while the "killing brain cells" claim is busted, the serious damage alcohol can inflict on brain structure and function is very real.