Scientists at Wake Forest University School of Medicine (United States) have shown that even modest amounts of alcohol can accelerate brain atrophywhich is the loss of brain cells, and increase the number of amyloid plaques, which are the buildup of toxic proteins in Alzheimer’s disease.
Alzheimer’s disease is the most common form of dementia and represents between 60 and 80 percent of cases. Although current research suggests that alcohol use disorder is a risk factor in Alzheimer’s disease, the impact that this disorder has on disease pathology is an area of ongoing investigation.
Alcohol ‘accelerates the cascade’ of Alzheimer’s
“These findings suggest that alcohol may speed up the pathological cascade of Alzheimer’s disease in its early stages,” said Dr. Shannon Macauley, Associate Professor of Physiology and Pharmacology at Wake Forest University School of Medicine, whose preclinical study has been published in the scientific journal Neurobiology of Disease.
Using mouse models of Alzheimer’s disease-related pathology, the researchers employed a 10-week chronic drinking method in which mice were given a choice between drinking water or alcohol, imitating human behavior regarding alcohol consumption.
They then discussed how voluntary and moderate consumption of alcohol it altered healthy brain function and behavior and whether it altered the pathology associated with the early stages of Alzheimer’s disease.
The researchers found that alcohol increased brain atrophy and caused increased numbers of amyloid plaques, including increased numbers of smaller plaques, which could set the stage for increased plaque proliferation later in life.
Even moderate consumption increases the risk
Interestingly, the researchers also found that acute alcohol withdrawal increased beta-amyloid levelswhich is a key component of the amyloid plaques that accumulate in Alzheimer’s disease.
Other analyzes showed that the chronic alcohol exposure it misregulated cerebral and peripheral metabolism, another way of accelerating Alzheimer’s pathology. Macauley had previously shown that elevated blood sugar increases beta-amyloid and amyloid plaques.
In this study, the researchers found that even a moderate alcohol consumption it caused elevations in blood sugar and markers of insulin resistance, increasing the risk not only of Alzheimer’s, but also of other diseases such as type 2 diabetes and cardiovascular disease.
The study also found that moderate alcohol consumption altered the anxiety and dementia-related behaviors. “These preclinical findings suggest that even moderate alcohol consumption can lead to brain damage. Alcohol use may be a modifiable risk factor for Alzheimer’s disease and dementia,” Macauley said.
References
Stephen M. Day, Stephen C. Gironda, Caitlin W. Clarke, J. Andy Snipes, Noelle I. Nicol, Hana Kamran, Warner Vaughan, Jeffrey L Weiner, Shannon L. Macauley. Ethanol exposure alters Alzheimer’s-related pathology, behavior and metabolism in APP/PS1 mice. Neurobiology of Disease (2023). DOI: https://doi.org/10.1016/j.nbd.2022.105967