Researchers from US found that people who stick to recommended alcohol limits are still at risk, as well as bingers and heavy drinkers, the 'BBC news' reported.
The findings were presented at Alzheimer's Association International Conference in Vancouver, Canada.
The study tracked 1,300 women in their mid-60s for over 20 years. The risk of dementia which is a loss of brain function, was higher among those who reported drinking more alcohol.
Women who switched from abstinence to drinking over the course of the study also increased their risk.
Those who drank alcohol "in moderation", meaning seven to 14 alcoholic drinks a week, were also more likely to develop problems with memory and brain functioning that can be a warning sign of future dementia.
"In this group of older women, moderate alcohol consumption was not protective. Clinicians should carefully assess their older patients for both how much they drink and any changes in patterns of alcohol use," researcher Tina Hoang, of the Veterans Health Research Institute in San Francisco, said.
More From This Section
She said that it might be that brains become more vulnerable to the effects of alcohol as we age.
Another group of US researchers at the same meeting presented work showing the potential harms of binge drinking.
Among the 5,075 men and women they studied, those who reported heavy bouts of drinking at least one episode per month were more likely to experience dementia-like problems.
Fortnightly binges doubled the risk, the report said.