Excessive Drinking May Hasten Alzheimer's Progression if You Have a Genetic Risk
Michelle Milliken
Excessive alcohol consumption is linked with a variety of health issues, including high blood pressure, heart disease, liver disease, a weakened immune system, and breast cancer. It can also lead to learning and memory problems. A new study delved further into that last point, investigating the impact of alcohol abuse on those with a genetic risk for Alzheimer’s.
Scientists from Scripps Research and the University of Bologna recently teamed up to test whether alcohol use disorder impacted the progression of Alzheimer’s in those with a genetic predisposition to the disease. Using genetically engineered mice, the team found that repeated alcohol intoxication was linked with symptoms of cognitive decline appearing sooner that they typically would.
Dr. Federico Manuel Giorgi, co-lead author and professor of Computational Genomics at the University of Bologna, explains, “Adding ethanol to an Alzheimer’s genetic background pushes Alzheimer’s forward by a few months or a few years.”
To conduct their study, published in the journal eNeuro, researchers repeatedly exposed mice to alcohol over a period of several months, similar to the amount of exposure experienced by humans with alcohol use disorder. A group of the mice had three genes that made them susceptible to Alzheimer’s, and these were compared to a control group.
The study showed that alcohol-exposed mice had progressively worse learning and memory spatial patterns, and this happened sooner than it should have. The team then studied brain cells from mice that were exposed and not exposed to alcohol, finding that the first group had widespread changes in gene expression in the prefrontal cortex. These were associated with neuronal excitability, neurodegeneration, and inflammation.
The changes occurred in neurons, astrocytes, microglia, and endothelial cells. The team says this stands out because it had been thought that neurons carried out Alzheimer’s associated responses, but these other cell types have recently been understood to play a role in the development of the disease, as well.
Additionally, the researchers found that alcohol-exposed mice had gene transcription profiles more akin to those of older mice with more severe cognitive decline than mice their own age.
Dr. Pietro Paolo Sanna, co-lead author and professor of Immunology and Microbiology at Scripps Research, explains, “When we compared the alcohol-exposed mice to the same type of mice with early or late progression of the disease—so mice that are not yet impaired in any way and mice that are really compromised—we found that the effect of alcohol is to move gene expression towards the advanced disease.”
The researchers say studies like this may lead to a better understanding of how memory loss occurs, as they shed light on how gene expression changes in different cells in those with Alzheimer’s. The team believes that these gene transcription pathways may also help explain how the disease progresses without alcohol consumption.
Going forward, they hope to study whether alcohol consumption impacts the onset or progression of Alzheimer’s in those without genetic risk.
This isn’t the first research to link alcohol consumption with Alzheimer’s. Another recent study also found that a light to moderate amount of alcohol use may increase brain atrophy and amyloid plaques in those with an early form the disease. You can read more about that study here.
