Researchers used mice to show that small doses of alcohol can help clean waste matter from the brain, thereby reducing the risk of dementia
If you cannot do without a nightly tipple, it may actually be doing you some good.
A new study in the journal Scientific Reports, shows that low levels of alcohol consumption tamp down inflammation and helps the brain clear away toxins, including those associated with Alzheimer’s disease. “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. Daily intake of alcohol for 30 years at doses scalable to those in the present study reduces human hippocampal volume by 3.4–5.8% compared to abstainers,” the study concluded.
“Prolonged intake of excessive amounts of ethanol is known to have adverse effects on the central nervous system. 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,” said Maiken Nedergaard, co-director of the Center for Translational Neuromedicine at the University of Rochester Medical Center (URMC) and lead author of the study.
Animals that were exposed to low levels of alcohol consumption, analogous to approximately 2 ½ 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.
While excessive consumption of alcohol is a well-documented health hazard, many studies have linked lower levels of drinking with a reduced risk of cardiovascular diseases as well as a number of cancers.
Nedergaard’s research focuses on the glymphatic system, the brain’s unique cleaning process that was first described by Nedergaard and her colleagues in 2012. They showed how cerebral spinal fluid (CSF) is pumped into brain tissue and flushes away waste, including the proteins beta amyloid and tau that are associated with Alzheimer’s disease and other forms of dementia. Subsequent research has shown that the glymphatic system is more active while we sleep, can be damaged by stroke and trauma, and improves with exercise.
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.
Animals that were exposed to low levels of alcohol consumption, analogous to approximately 2 ½ 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. The low dose animals’ performance in the cognitive and motor tests was identical to the controls.
“The data on the effects of alcohol on the glymphatic system seemingly matches the J-shaped model relating to the dose effects of alcohol on general health and mortality, whereby low doses of alcohol are beneficial, while excessive consumption is detrimental to overall health” said Nedergaard.
