Go ahead and drink that glass of wine, as new research shows that moderate social drinking reduces the risk of dementia and cognitive impairment.
Researchers at Loyola University Chicago Stritch School of Medicine conducted an analysis of 143 studies and found that moderate drinkers were 23 percent less likely to develop cognitive impairment, Alzheimer's disease and other forms of dementia, a press release from the school stated.
The findings are reported in the journal Neuropsychiatric Disease and Treatment.
For this research, moderate drinking was defined as a maximum of two drinks per day for men and one drink per day for women.
Authors Edward J. Neafsey and Michael A. Collins, professors in the Department of Molecular Pharmacology and Therapeutics, reviewed studies dating back to 1977, which included more than 365,000 participants.
Of these studies, 74 papers calculated the ratios of risk between drinkers and nondrinkers, while 69 papers stated whether cognition in drinkers was better, the same or worse than cognition in nondrinkers.
They found that wine was more beneficial than beer or spirits.
But this finding, according to researchers, was based on a relatively small number of studies, as most papers didn't distinguish among different types of alcohol.
On the other hand, heavy drinking ? more than three to five drinks per day ? was associated with a higher risk of cognitive impairment and dementia. But this finding wasn't statistically significant, the release noted.
We don't recommend that nondrinkers start drinking, Neafsey said. But moderate drinking ? if it is truly moderate ? can be beneficial.
Other findings include:
- 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;
- The beneficial effect of moderate drinking was seen in 14 of 19 countries, including the United States. In three of the remaining five countries, researchers also found a benefit, but it was not strong enough to be statistically significant;
- The findings were similar across different types of studies (longitudinal cohort studies, case-control studies and cross-sectional studies).
But researchers don't know why is it that moderate drinking can have a beneficial effect.
One theory is that the well-known cardiovascular benefits of moderate alcohol consumption, such as raising good HDL cholesterol, can also improve blood flow in the brain and thus, brain metabolism.
Another possible explanation involves sick quitters, which states that nondrinkers have a higher risk of cognitive impairment and dementia because the group includes former heavy drinkers who damaged their brain cells before quitting.
Neafsey and Collins's analysis didn't support this explanation. Instead, they found that in studies that excluded former heavy drinkers, the protective effect of moderate drinking still held up.
So Neafsey and Collins suggest a third possible explanation, which states that small amounts of alcohol might, in effect, make brain cells more fit. Alcohol in moderate amounts stresses cells and therefore, toughens them up to cope with major stresses down the road that could cause dementia, the release stated.
The researchers did note however, that there are other things besides moderate drinking that can reduce the risk of dementia. Those things including exercise, education and a Mediterranean diet high in fruits, vegetables, cereals, beans, nuts, and seeds.
Even gardening has been shown to reduce the risk of dementia, the release stated.