New research from the Texas A&M University Naresh K. Vashisht College of Medicine at Texas A&M Health suggests that the relationship between alcohol use and Alzheimer's disease is more complex than previously believed, according to a July 9 announcement. The study found that alcohol interacts differently with amyloid-beta-related and tau-related pathology in animal models, which are two key processes involved in Alzheimer's disease.
The research was led by Dr. Yufei Huang, a postdoctoral research associate in the lab of Dr. Jun Wang, professor in the Department of Neuroscience and Experimental Therapeutics. The team focused on how alcohol affects brain circuits important for behavioral flexibility—a function often impaired both in addiction and Alzheimer's disease.
"We started thinking about whether the same circuits involved in flexibility and adaptation might also be important in Alzheimer's disease," Huang said.
The study examined a brain circuit called the corticostriatal circuit, which helps control decision-making and behavioral flexibility. Using animal models representing different Alzheimer’s-related features—one based on amyloid-beta protein plaques and another on tau protein tangles—the researchers observed surprising results. Alcohol reduced communication within this neural pathway for amyloid-beta pathology but increased it for tau pathology.
"The results were almost the opposite of what we expected," Huang said. "To us, this highlights an important principle in biology: Combining two risk factors does not always produce a simple additive effect." The findings indicate that combining risk factors like alcohol exposure with specific types of Alzheimer’s pathology can have unexpected effects rather than simply intensifying existing problems.
Beyond neural signaling changes, the study also reported that alcohol may disrupt immune cell responses—specifically microglia—in brains with amyloid accumulation. "Alcohol not only altered brain circuit function but also appeared to disrupt immune cell responses in the brain," Huang said.
While these findings are based on animal models, researchers say they raise questions about how alcohol might affect people who already have early signs or genetic risks for Alzheimer’s disease differently from others. The team hopes future studies will examine human subjects using biomarkers such as amyloid, tau, and inflammation markers to clarify these effects.
