The results of this study support findings from previous research on the topic: In the last three decades, the association between moderate alcohol intake and cognitive function has been investigated in 68 studies comprising 145,308 men and women from various populations with various drinking patterns. Most studies show an association between light to moderate alcohol consumption and better cognitive function and reduced risk of dementia, including both vascular dementia and Alzheimer's Disease.
Such effects could relate to the presence in wine of a number of polyphenols (antioxidants) and other micro elements that may help reduce the risk of cognitive decline with ageing. Mechanisms that have been suggested for alcohol itself being protective against cognitive decline include effects on atherosclerosis ( hardening of the arteries), coagulation ( thickening of the blood and clotting), and reducing inflammation ( of artery walls, improving blood flow).
Source: Boston University Medical Center