Chronic effects of low to moderate alcohol consumption on structural and functional properties of the brain: beneficial or not?

Objective Some studies suggest that the effects of low to moderate drinking (about 1-3 standard glasses of alcohol per day) on the brain and cognitive rerformance are positive. In the present study this hypothesis is investigated. Methods For this purpose studies on the effects of low to moderate drinking on brain structure (Magnetic Resonance Induction (MRI) studies) and on cognitive performance were analysed and discussed Results In MRI studies, a linear negative effect of alcohol consumption on brain volume was found. Furthermore, a linear decrease in grey matter concurring with a linear increase in white matter volumes as a function of number of drinks was reported in males, but not in females. Only in elderly low to moderate drinkers (aged > 65 years) there appeared to be an U-shaped relationship between alcohol consumption and white matter integrity (grade) on the one hand and cognition on the other hand. Conclusions The changes reported in brain shrinkage, grey matter and white matter volume, as a result of low to moderate alcohol consumption sooner offer support for the contention that such drinking decreases brain health than for its beneficial effect. An exception might hold for elderly light and moderate drinkers where less white matter damage was found than in abstainers concurring with better cognitive performance. However, methodological problems impose limits on this conclusion. Copyright (C) 2009 John Wiley & Sons, Ltd.