Although excessive alcohol consumption is a well-documented health hazard, many studies have linked lower levels of drinking with a reduced risk of cardiovascular disease and cancer. Researchers at the University of Rochester Medical Center (URMC) have added to this growing body of research with a study, published in Scientific Reports, indicating that low levels of alcohol consumption tamp down inflammation and help the brain clear away toxins, including those associated with Alzheimer’s disease.
“Prolonged intake of excessive amounts of ethanol is known to have adverse effects on the central nervous system,” says Maiken Nedergaard, co-director of the Center for Translational Neuromedicine at URMC and lead author of the study. “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’s research focuses on the glymphatic system, the brain’s unique cleaning process 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, which are associated with dementia.
The new study looked at the impact of both acute and chronic alcohol exposure on mice. Animals exposed to high levels of alcohol over a long period of time exhibited high levels of a molecular marker for inflammation, particularly in cells that are key regulators of the glymphatic system. However, animals that were exposed to levels of alcohol analogous to approximately two-and-a-half drinks per day showed less inflammation in the brain than mice who were not exposed to alcohol. In addition, their glymphatic system was more efficient in moving CSF through the brain and removing waste.
“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,” explains Nedergaard. “This study may help explain why this occurs. Specifically, low doses of alcohol appear to improve overall brain health.”