A 10-year study involving 19,887 middle-aged and older Americans, who completed surveys every two years about their health and lifestyle, has found that those who had a drink or two a day tended to show less cognitive decline, compared to non-drinkers.

Cognitive function was measured in a series of tests looking at their overall mental status, word recall and vocabulary. Their test results were combined to form a total cognitive score.

Age, smoking and education level were controlled for.

However, it is still hard to say whether the link is causal or correlational. The researchers do not encourage anyone to start drinking in order to prevent cognitive function decline.

The association was also stronger among white participants versus African American participants, which perhaps adds weight to the view that the association is correlational, that is, linked to other behaviors which are the true reason.