That after work glass of red wine may be less medicinal than you thought. Researchers have found that drinking even moderate amounts of alcohol shrinks the brain.

Brain volume naturally decreases by nearly 2 percent per decade as people age, but scientists had speculated that moderate alcohol intake could slow this process, by improving heart function and blood flow.

However, U.S. researchers have dealt a blow to that theory, finding a "significant negative linear relationship" between the amount of alcohol someone consumes and the space their brain takes up.

While men were more likely to drink alcohol, the researchers examined magnetic resonance imaging scans of drinkers' and non-drinkers' brains, and found the association was stronger in women. They speculated this could be due to women's smaller stature and greater tendency to feel alcohol's effects.

The study, which was based on an analysis of drinking habits and brain volume in nearly 2,000 U.S. adults between 1999 and 2001, found that while the brains of people who never touched alcohol occupied nearly 78.6 percent of their cranial space on average, this dropped to about 78.2 percent in people who previously drank but had since quit, and dropped again, to just under 77.8 percent, for moderate drinkers.

Heavy drinkers were lower still, at 77.2 percent.

"The public health effect of this study gives a clear message about the possible dangers of drinking alcohol," the authors concluded in the study, published yesterday in the Archives of Neurology. "This study suggests that, unlike the associations with cardiovascular disease, alcohol consumption does not have any protective effect on brain volume."

Click here to read more from the Australian.