ALZHEIMER: Even moderate alcohol consumption accelerates brain atrophy

The researchers point out that Alzheimer’s disease is the most common form of dementia, representing 60 to 80% of dementia cases, according to the Alzheimer’s Association. More recent research suggests that alcohol use disorders may be a risk factor in Alzheimer’s disease, however the underlying processes remain poorly understood.

“Our study suggests that alcohol may accelerate the pathological cascade of early Alzheimer’s disease,” says lead author Dr. Shannon Macauley, associate professor of physiology and pharmacology at Wake Forest.

Alcohol, a modifiable risk factor for Alzheimer’s and dementia

The study is conducted on mouse models of Alzheimer’s disease with access to either water or alcohol. The researchers then explored how voluntary and moderate alcohol consumption might alter brain function and whether it contributed to triggering the early stages of Alzheimer’s disease. These experiments reveal that:

• alcohol increases brain atrophy and induces an increase in the number of amyloid plaques, including a greater number of smaller plaques, which sets the stage for more plaque proliferation later in life;
• acute alcohol withdrawal increases levels of beta-amyloid and therefore the risk of formation of amyloid plaques characteristic of Alzheimer’s;
• chronic exposure to alcohol deregulates cerebral and peripheral metabolism, which further accelerates the pathology: the same team had already shown that high blood sugar increases amyloid and beta-amyloid plaques;
• in this study, even moderate alcohol consumption leads to an increase in blood sugar and markers of insulin resistance and thus increases the risk not only of type 2 diabetes and cardiovascular disease, but also of Alzheimer’s;
• finally, moderate consumption modifies behaviors linked to anxiety and dementia, once established

“Even moderate alcohol consumption can lead to brain damage,” conclude the researchers who confirm the consumption of alcohol as “a modifiable risk factor for Alzheimer’s disease and dementia”.