Study: Alcohol Appears to Reduce Risk of Alzheimer's

Light to moderate consumption of alcohol appears to reduce the risk of dementia in older people, including that of Alzheimer's disease, regardless of the type of drink consumed, according to researchers at Erasmus University Medical School, Rotterdam, Netherlands.

Researchers looked at the relationship between alcohol consumption and the risk of dementia in participants in the Rotterdam Study, a prospective population-based study of approximately 8,000 people, aged 55 and older. Participants who did not have symptoms of dementia at the start of the study (1990 - 1993) and who had complete data on their consumption of alcohol were included in the study.

Investigators compared the risk of developing dementia between people who regularly drank alcohol with those who did not. The average follow-up was 6 years. During that time, 197 participants developed dementia (146 Alzheimer's disease, 29 vascular dementia, 22 other dementia). The average alcohol consumption was .29 drinks per day.

Light-to-moderate consumption of alcohol (1 to 3 drinks per day) was associated with a 42 percent risk reduction of all dementia, and approximately 70 percent risk reduction of vascular dementia. The reduction of risk was not related to the type of alcoholic drinks consumed, the researchers reported in The Lancet.

Researchers speculate that alcohol might reduce the cardiovascular risk profile as ethanol has been shown to reduce platelet aggregation, or by altering the blood-lipid ratio. Alcohol may also have an effect on cognition by stimulating the release of acetylcholine in the brain's hippocampus. Acetylcholine has been shown to facilitate memory and learning processes. However, a high consumption of alcohol inhibits production of acetylcholine.

"In recent years, evidence has been accumulating that vascular factors may be involved in the cause of dementia, both vascular dementia and Alzheimer's disease," said Monique Breteler, co-author of the study. "Our findings lend further support to the vascular hypothesis of dementia. We saw some indication for a stronger relation with alcohol in persons with a genetically determined susceptibility for Alzheimer's disease. Our findings can help focus research into the specific mechanisms that underlie the development of dementing illnesses."

Other sources: The Lancet