There is much uncertainty about the effects of alcohol on cognitive function and a recent study has only added to the confusion.

Despite several observational cohort studies indicating that moderate alcohol consumption can improve the brain's performance, many have criticised such investigations for their vulnerability to distortion by lifestyle and physiologic factors.

However, a new study that applied a Mendelian randomised approach has yielded little success either.

Researchers used aldehyde dehydrogenase 2 (ALDH2) geneotype (AA, GA OR GG) as a variable and assessed cognitive function from delayed 10-word recall scores and Mini-Mental State Examination scores.

The Mendelian study showed no link between brain performance and alcohol intake but the ALDH2 variant was only present in three per cent of the variances in reported alcohol intakes.

This threw the reliability of the study into question, as did its failure to take into account drinking patterns.

Consequently, further research is needed to discovery if alcohol has positive effects upon the brain.