2 drinks a day may be good for brain: Study

Besides helping you relax, a couple of glasses of wine after a busy day may tamp down inflammation and help the brain clear away toxins, including those associated with Alzheimer's disease, suggests new research.

While excessive consumption of alcohol is a well-documented health hazard, the new study, published in the journal Scientific Reports, points to the health benefits of low doses of alcohol.

"Prolonged intake of excessive amounts of ethanol is known to have adverse effects on the central nervous system," said lead author of the study Maiken Nedergaard from the University of Rochester Medical Center (URMC) in the US. 

"However, in this study we have shown for the first time that low doses of alcohol are potentially beneficial to brain health, namely it improves the brain's ability to remove waste," Nedergaard said. 

Nedergaard's research focuses on the glymphatic system, the brain's unique cleaning process.

In an earlier research, they showed how cerebral spinal fluid (CSF) helps the brain flush away waste, including the proteins beta amyloid and tau that are associated with Alzheimer's disease and other forms of dementia. 

The new study, which was conducted in mice, looked at the impact of both acute and chronic alcohol exposure. 

When they studied the brains of animals exposed to high levels of alcohol over a long period of time, the researchers observed high levels of a molecular marker for inflammation, particularly in cells called astrocytes which are key regulators of the glymphatic system. 

They also noted impairment of the animal's cognitive abilities and motor skills.

But animals that were exposed to low levels of alcohol consumption, analogous to approximately two and a half drinks per day, actually showed less inflammation in the brain and their glymphatic system was more efficient in moving CSF through the brain and removing waste, compared to control mice who were not exposed to alcohol. 

"low doses of alcohol appear to improve overall brain health," Nedergaard said.