Mild cognitive impairment -- the classification used to describe the stage between normal aging and dementia -- is characterized by mild memory or cognitive problems but no significant disability.

For the study, investigators followed the progression of mild cognitive impairment to dementia in 121 participants aged 65 to 84. Those who consumed up to one alcoholic beverage per day developed dementia 85 percent slower than those who never drank alcohol.

"The mechanism responsible for why low alcohol consumption appears to protect against the progression to dementia isn't known," said study authors Vincenzo Solfrizzi, MD, PhD, and Francesco Panza, MD, PhD, with the Department of Geriatrics at the University of Bari, in Bari, Italy.

"However, it is possible that the arrangement of blood vessels in the brain may play a role in why alcohol consumption appears to protect against dementia," they hypothesized. "This would support other observations that drinking moderate amounts of alcohol may protect the brain from stroke and vascular dementia."

The researchers found no link between drinking more than one alcoholic beverage daily and slower progression to dementia when compared to not drinking at all.