A tipple a day keeps the doctor away

Alcohol consumption is bad for your health. This phrase is drummed into us from a young age, and as a result the dangers of drinking are understood by almost everyone (even if we choose to ignore them). However, new research from the journal Scientific Reports suggests that low level alcohol consumption can actually be good for the brain.

A study led by Maiken Nedergaard at the University of Rochester Medical Center investigated the effect of alcohol on the brain. "Prolonged intake of excessive amounts of ethanol is known to have adverse effects on the central nervous system," said Nedergaard, "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 and her team studied the glymphatic system, the brains unique method for clearing away waste which was first described by Nedergaard and colleagues in 2012. It works by pumping cerebrospinal fluid (CSF) into the parenchyma, exchanging solutes with interstitial fluid which is then cleared from the brain. This removes proteins such as beta amyloid and tau, among other waste products, which are associated with Alzheimer’s disease and other dementias. The system is more active while we sleep, suggesting that a major function of sleep is the clearance of metabolites that are produced when awake.

The study analysed molecular markers for inflammation in mice brains, more specifically in astrocytes, a type of neuron support cell that is a key regulator of the glymphatic system. Animals exposed to high levels of alcohol over a long period of time showed high levels of the inflammatory markers, alongside impairment in cognitive and motor function. However, animals that were exposed to much lower levels of alcohol, the equivalent of 2.5 drinks per day, produced less inflammatory markers  than both the high-alcohol group and the control group (no alcohol). There was also evidence that the glymphatic system was more efficient, moving the CSF through the brain more quickly, removing a greater amount of waste. Cognitive and motor function was the same as in the control group.

These findings add to a small but expanding body of research that highlight the health benefit of low-dose alcohol, with many studies linking this with lower levels of cardiovascular disease and certain cancers. "Studies have shown that low-to-moderate alcohol intake is associated with a lesser risk of dementia, while heavy drinking for many years confers an increased risk of cognitive decline. This study may help explain why this occurs. Specifically, low doses of alcohol appear to improve overall brain health” said Nedergaard.