They assessed alcohol use by asking participants how often they had 12-ounces of beer, six ounces of wine or shots of liquor. As for white matter disease, light drinking was associated with less white matter disease, but moderately heavy drinking was associated with more white matter disease. Compared with non-drinkers, light drinkers were 32 percent less likely to have injured areas in their white matter. Mukamal and colleagues previously found that small areas of injury and scarring in the white matter correlate with impaired intellectual ability and motor skills such as opening a lock, buttoning a shirt and walking. They also showed that silent strokes and greater brain atrophy are associated with poorer brain function.
Brain atrophy means the brain matter has shrunk, often because brain cells are dying or dead.
The cells may die because they are injured by alcohol. But even at low doses, alcohol consumption was associated with greater brain atrophy. Moderately heavy drinkers have the fewest strokes but more white matter disease and the most atrophy. In addition, alcohol is known to be a mild blood thinner, so it could offer protection from silent strokes caused by tiny blood clots in the brain, he says. Brain atrophy and drinking were linked in a dose-dependent manner, suggesting that even low levels of alcohol use may contribute to brain shrinkage, he notes.