Does drinking alcohol really kill brain cells?

By John Murphy, MDLinx
Published February 26, 2020

Key Takeaways

Popular wisdom holds that “every alcoholic drink you take kills 1,000 brain cells.” Is it true? Does drinking alcohol really destroy brain cells? 

The short answer: No. Drinking alcohol doesn’t kill brain cells. While research by some investigators suggests that alcohol exposure can result in neuronal cell death, many experts say that alcohol doesn’t truly kill brain cells. 

In fact, in one study, researchers actually counted the number of neurons in the brains of drinkers and non-drinkers during postmortems. They found that people from either group averaged about the same numbers of neurons regardless of alcohol use. 

But that doesn’t mean that alcohol is harmless to your little gray cells.

“Just because alcohol doesn’t actually kill brain cells, it doesn’t mean it doesn’t affect them,” warned Benjamin Springgate, MD, MPH, associate professor of clinical medicine, Louisiana State University Schools of Medicine and Public Health, New Orleans, LA. “Studies have shown that drinking alcohol can damage the ends of brain cells, which affect how they communicate with one another and how your brain works. Long term heavy drinking can not only shrink the size of brain cells and affect coordination, sleep, and memory, it can result in enough damage to result in coma and even death.” 

This much is true—alcohol doesn’t kill brain cells, but it injures and impairs your brain in a number of ways: 

Dulls dendrites

Chronic alcohol use can damage dendrites, the branch-like ends of brain cells. Used for neurotransmission, dendrites are the receiving end of the neuron. So the degradation of dendrites can impair brain signaling, causing defects in cognitive function (eg, memory, problem solving, and attentional focus). 

On the bright side, researchers have recently shown that certain therapies (such as donepezil, an Alzheimer drug) can reverse alcohol-related dendritic damage. 

Shrinks your brain

Heavy alcohol use is associated with smaller brain volume, suggesting that drinking literally shrinks your brain. Even at moderate levels of alcohol consumption, the brain showed shrinkage—particularly the hippocampus, the brain region associated primarily with memory. 

Researchers found that hippocampal atrophy occurred in a dose-dependent manner—the more you drink, the more brain you shrink. For instance, moderate drinkers (around two drinks per day) had three times the risk of hippocampal shrinkage as nondrinkers. People who drank the equivalent of four drinks a day had nearly six times the brain shrinkage as nondrinkers. 

In addition, higher alcohol consumption was linked with a greater decline in lexical fluency (ie, saying as many words as possible starting with the same letter in 1 minute), which is a measure of executive function. However, higher alcohol intake did not show declines in word recall or in semantic fluency (ie, saying as many words as possible in the same category in 1 minute).

Stunts brain cell growth

Although alcohol doesn’t kill brain cells, it may prevent new brain cells from growing. Too much alcohol can meddle with neurogenesis, the process of forming new neurons. 

This can happen in multifarious ways, according to researchers. Alcohol is a “pharmacologically promiscuous drug” because it acts on many targets, including several that are involved in neurogenesis, researchers explain

The good news, according to these authors, is that people who quit drinking alcohol can recover the ability to grow new neurons, although perhaps not to the full extent of a nondrinker. 

Hastens dementia 

Heavy drinking in middle-aged adults is associated with a higher risk of dementia--but so is teetotaling, according to the authors of a large prospective cohort study. The greater the alcohol consumption, the greater the risk. However, light to moderate drinking (about two or fewer drinks per day) is actually associated with a reduced risk of dementia. 

But, why do teetotalers also have a greater risk of dementia? The authors pointed to a greater risk of cardiometabolic disease in this group, and cardiometabolic disease itself is linked to a greater risk of dementia. 

Bottom line

Not all the news is bad. Alcohol has also been linked to some potentially positive effects, such as a protective effect from ischemic stroke in older people. But most experts say the serious dangers of any amount of alcohol far outweigh the possible benefits. 

“So even though your mom and ‘em were not right about alcohol zapping your brain cells, it can impair them, especially if you drink too much,” warned LSU’s Dr. Springgate. “And that’s something to think about before you take that second or third drink.”

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