A long busy day at work? How about a nice glass of wine to wind down? That sounds like a fine idea to a lot of people. Turns out, it is a healthy idea as well. While it has been established that binge drinking can post a host of health problems including mental and behavioural disorders, low doses of alcohol have been shown to be beneficial to brain health.
A recent study published in February 2018 in the Scientific Reports revealed that low levels of alcohol consumption can help improve the brain’s natural detoxification process. This adds to the body of evidence which pointed to the health benefits conferred by low alcohol consumption including lowered risks of heart diseases as well as a number of cancers.
The research group led by Dr. Maiken Nedergaard, from the University of Rochester Medical Center investigated the effects of acute and chronic alcohol (ethanol) exposure on the glymphatic system, a functional waste clearance pathway in the central nervous system (CNS) which consists of the brain and spinal cord. Nedergaard revealed in her previous research that glymphatic system is responsible for cerebral spinal fluid-interstitial fluid exchange that drains waste products out from the brain including toxic proteins such as beta amyloid and tau which are linked to Alzheimer’s disease.
The present animal study revealed that acute exposure to binge (1.5mg/kg) and high levels (4mg/kg) of alcohol dramatically suppressed the function of glymphatic system in mice. In addition to suppressing the glymphatic function, chronic exposure to binge alcohol level also raised the inflammatory markers particularly in cells called astrocytes which are the key regulators of glymphatic system. Chronic high level of alcohol was not tested as it was associated with high mortality rate in mice.
Interestingly, both acute and chronic exposure to low level of alcohol (0.5mg/kg) boosted glymphatic function. Binge level of alcohol exposure (but not the low dose alcohol) was also found to be associated with impaired cognitive and motor functions.
The finding pertaining to the effects of different levels of alcohols on the glymphatic system appears to concur with the existing model of dose effects of alcohol on general health and mortality i.e. low levels of alcohol are beneficial to health whereas excessive consumption can post hazards to overall health.
More importantly, the outcome of this study may well point to the health benefit of low dose (0.5mg/kg) of alcohol at delaying the onset of Alzheimer’s disease and non-Alzheimer’s dementia. As it seems, the sweet spot is equivalent to 2.6 standard daily drinks per day (for a 70 kg individual).
This study was performed on mice and should not be used as a guideline for alcohol consumption in humans. However, it does provide us a glimpse on another potential benefit of low dose alcohol consumption.
- Lundgaard I, Wang W, Eberhardt A, Vinitsky HS, Reeves BC, Peng S, Lou N, Hussain R &, Nedergaard M. (2018) Beneficial effects of low alcohol exposure, but adverse effects of high alcohol intake on glymphatic function. Scientific Reports, 2018; 8 doi:10.1038/s41598-018-20424-y
- WHO (2015) Alcohol Fact Sheet http://www.who.int/mediacentre/factsheets/fs349/en/