This relationship between alcohol consumption and brain health has been less clear. Chronic, excessive use is a risk factor for the development of all forms of dementia. What has been less understood has been if alcohol and the brain follows a typical dose response curve seen for its intake and other diseases. Some new research is suggesting it may.
The study examined the impact of 3 different daily doses of alcohol on brain “glymphatic flow” and inflammation in mice. Brain glymphatic flow is the equivalent to lymphatic flow in the rest of the body. The lymphatic system is used as a “highway” that the immune system uses to remove different toxic waste generated by infections or other exposures.
It was thought until recently that no lympathic flow occurred in the brain which created a mystery about how it detoxifies efficiently. Recently some innovative research injected mice with a tracer that glows when exposed to a specific type of light into the lymphatic system to better see all of its pathways. Surprisingly, the brain lit up as did the rest of the body confirming that there is lymphatic flow in this area. The term for it was coined as glymphatic flow.
In the recent alcohol study, low alcohol intake increased glymphatic flow 39.8% compared to the control group consuming none. Higher consumption did just the opposite decreasing this flow. The response in inflammatory markers followed the same pattern, improving with low dose consumption and increasing with high dose.
While this was an animal model study, dose impact studies on the relationship between alcohol and other health risks such as cardiovascular disease have supported the “dose response” relationship with 1-2 drinks daily decreasing the risk compared to non-drinkers and high dose use increasing the risk. The relationship appears to be similar in the brain.
Lundgaard et al. Beneficial effects of low alcohol exposure, but adverse effects of high alcohol intake on glymphatic function. Scientific Reports, 2018;8:2246.