Drinking 'almost halves dementia risk'

Older Australians who indulge in up to 28 drinks a week stand a better chance of warding off dementia than those who abstain, according to a new study.

Data compiled from 15 international studies, including responses from more than 10,000 people, found that drinkers, not teetotallers, are better off when it comes to developing diseases affecting cognitive function.

Those aged 60 and older who consumed between one and 28 alcoholic drinks each week, were almost 30 per cent less likely to have Alzheimer's later on in life, the data found.

Light and moderate drinkers were also 25 per cent less likely to contract vascular dementia, and 26 per cent less likely to suffer from any form of dementia.

The odds improved even more when comparing just drinkers with non-drinkers and ignoring exactly how much people consumed.

The report, Alcohol Consumption as a Risk Factor for Dementia and Cognitive Decline, was published in the July edition of the American Journal of Geriatric Psychiatry.

But Professor Kaarin Anstey, from Canberra's Australian National University, warned this was not encouragement for people to start swilling 28 glasses of alcohol a week.

Even though the study found imbibers, in general, had a 47 per cent reduced risk of contracting dementia compared with teetotallers, down to 44 per cent for Alzheimer's.

"This article used all published studies to include one to 28 drinks per week, but in some countries (the range) differed, they were higher in some and lighter in others," she told AAP.

"Australian guidelines, for instance, don't say 28 drinks is moderate."

But apart from that point of difference, there was a clear link between drinking and a reduced risk of dementia.

There also appeared to be no difference between the sexes, Prof Anstey said.

Although it was unclear exactly why light drinking provoked such a benefit, she suggested it might have something to do with alcohol's "protective effect" on reducing inflammation and heart disease.

More work needs to be done examining drinking in early life and exactly what kinds of alcohol help, Prof Anstey said.