Knowledge regarding environmental factors influencing the risk of Alzheimer's disease is surprisingly scarce, despite substantial research in this area. In particular, the roles of smoking and alcohol consumption still remain controversial. A new study published this month in the Journal of Alzheimer's Disease suggests a protective effect of alcohol consumption on the risk of Alzheimer's disease, particularly in women who do not smoke.

Researchers at the University of Valencia, the Generalitat Valenciana, and the Institut Municipal d'Investigació Mèdica, Barcelona, in Spain, carried out a study comparing personal and clinical antecedents of subjects affected with Alzheimer's disease with healthy people, both groups with the same age and gender distribution. Women included in the study were mainly light or moderate alcohol consumers. The risk of Alzheimer's disease was unaffected by any measure of tobacco consumption, but a protective effect of moderate alcohol consumption was observed, this effect being more evident in nonsmoker women.

"Our results suggest a protective effect of alcohol consumption, mostly in nonsmokers, and the need to consider interactions between tobacco and alcohol consumption, as well as interactions with gender, when assessing the effects of smoking and/or drinking on the risk of AD," according to lead investigator Ana M. Garcia, PhD, MPH, Department of Preventive Medicine and Public Health, University of Valencia.

"Interactive effects of smoking and drinking are supported by the fact that both alcohol and tobacco affect brain neuronal receptors."