Australasian Science: Australia's authority on science since 1938

Alcohol Doesn’t Dull the Minds of Older Men

Older men who consume alcohol excessively are not more likely to suffer from cognitive impairment in later life, according to research reported in Neurology.

“Heavy alcohol consumption is known to be detrimental to health, so these results were counterintuitive,” said lead author Professor Osvaldo Almeida of The University of Western Australia.

Almeida said that a commonly held belief, based on previous association studies, was that excessive alcohol use is a cause of cognitive impairment. However, the link had never actually been proven. He and his fellow researchers decided to test the theory by examining a gene that determines how successfully a person is able to metabolise alcohol – that is, their degree of tolerance for alcohol.

The researchers incorporated genetic data from 3542 men between the ages of 65 and 83 years into traditional epidemiologic methods. Participants were asked about their alcohol consumption over the previous year, and classified as abstainers, occasional drinkers or regular drinkers depending on the number of standard drinks they consumed per week. Consuming more than 35 standard drinks per week was classified as alcohol abuse.

Their degree of cognitive impairment – defined as a decrease in the brain’s processing speed and efficiency as well as a deterioration in memory – was tested against a validated scale 6 years later.

Almeida said that if heavy alcohol use is a direct cause of cognitive impairment, then people with the genetic variant that makes them avoid alcohol should have a lower risk of cognitive impairment later in life. However, that was not the case.

The study concluded that alcohol consumption, including heavy regular drinking and abuse, was not a direct cause of cognitive impairment in later life. Rather, indirect causes – such as poor nutrition and head injury – were more likely to be responsible for the association between alcohol abuse and cognitive impairment.

In addition, the authors wrote: “Our results are consistent with the possibility, but do not prove, that regular moderate drinking decreases the risk of cognitive impairment in older men”.

Almeida said that the study was limited to older men and it was unclear if the results could be generalised to other age groups or women.