Moderate social drinking - a maximum of two drinks per day for men and 1 drink per day for women - significantly reduces the risk of dementia and cognitive impairment, according to a new study.
Edward J. Neafsey, PhD. and Michael A. Collins, PhD., professors in the Department of Molecular Pharmacology and Therapeutics, reviewed studies dating to 1977 that included more than 365,000 participants.
The study found that moderate drinkers were 23 percent less likely to develop cognitive impairment or Alzheimer's disease and other forms of dementia.
Wine was more beneficial than beer or spirits. But this finding was based on a relatively small number of studies, because most papers did not distinguish among different types of alcohol.
Heavy drinking (more than 3 to 5 drinks per day) was associated with a higher risk of cognitive impairment and dementia, but this finding was not statistically significant, the study days.
"We don't recommend that nondrinkers start drinking," Neafsey said. "But moderate drinking-if it is truly moderate-can be beneficial."
The study found the protective effect of moderate drinking held up after adjusting for age, education, sex and smoking. There was no difference in the effects of alcohol on men and women and the beneficial effect of moderate drinking was seen in 14 of 19 countries, including the United States.
The study has been published in the journal Neuropsychiatric Disease and Treatment.