People who drink an occasional glass of wine may have a lower risk of developing Alzheimer's disease and other forms of dementia, according to researchers at the Institute of Preventive Medicine at Kommunehospitalet in Copenhagen, Denmark.

Those who drank wine weekly or monthly were more than two times less likely to develop dementia, according to the study published in the journal Neurology. However, people who drank wine every day were no more or less likely to develop dementia.

"These results don't mean that people should start drinking wine or drink more wine than they usually do," said Dr. Thomas Truelsen, author of the study. "But the results are exciting because they could mean that substances in wine reduce the occurrence of dementia. If that's the case, we could potentially develop treatments or prevention methods based on these substances."

Researchers speculate that flavonoids, natural antioxidants, may be responsible for the beneficial effect. Red wine contains a high amount of flavonoids.

In the 1970s, researchers looked at the drinking patterns of 1,709 people and then assessed them for dementia in the 1990s. A total of 83 people developed dementia. Their alcohol consumption was compared to that of those who did not develop dementia.

The study also found that occasional beer consumption was linked with an increased risk of developing dementia. People who drank beer monthly were more than two times more likely to develop dementia than those who never or rarely drank beer.

"Research suggests that wine drinkers may have better dietary habits than beer and liquor drinkers," said Dr. John Brust, New York neurologist and author of an accompanying editorial. "There is also evidence that dietary vitamin E may reduce the risk of developing Alzheimer's. These factors were not accounted for in this study. Nonetheless, this is a provocative report providing evidence that there is indeed something specifically beneficial about wine."

Other sources: American Academy of Neurology