Scientists have discovered a potential link between high-fat diets and the development of Alzheimer’s disease, casting new light on the impact of our eating habits on brain health. 

Published in the Spanish journal Nutrients, the study presents evidence that unhealthy eating habits may contribute to the onset of Alzheimer’s, the leading cause of dementia worldwide.

Alzheimer’s disease impairs memory and cognitive functions, affecting millions globally. While its exact causes remain elusive, factors such as genetics, aging, and lifestyle are known contributors. The recent findings add another piece to this complex puzzle, suggesting that a diet rich in fats could play a significant role in increasing Alzheimer’s risk.

“The results of this study are a step forward in our understanding of this disease and may explain the relationship between obesity, Type 2 diabetes and the onset of Alzheimer’s. The findings also offer new targets for the possible prevention and treatment of the disease,” the study’s author, Mònica Bulló, who is a researcher at the Universitat Rovira i Virgili, said in a press release, Brain Tomorrow reports.

The researchers at the Universitat Rovira i Virgili conducted the study using two sets of mice — one normal and the other genetically modified to display Alzheimer’s-like symptoms. Each set was divided into two groups: one was fed a standard diet, while the other received a high-fat regimen.

Not surprisingly, those on the high-fat diet gained significant weight and showed signs typical of Type 2 diabetes, such as disturbed glucose and insulin metabolism.

However, the study’s most striking discovery involved microRNAs (miRNAs) — small molecules crucial for regulating gene expression. The researchers found that a specific miRNA, miR-19a-3p, was notably increased in the blood, cortex, and hippocampus — the brain area pivotal for memory — of the Alzheimer’s-prone mice. This miRNA also saw heightened levels in the normal mice subjected to a high-fat diet, hinting at a connection between diet, metabolic health issues, and Alzheimer’s disease.

Furthermore, the research identified that a high-fat diet raised the levels of two other miRNAs, miR-34a and miR-146a, across both mice groups. These molecules have previously been associated with insulin resistance, inflammation, and the development of toxic protein aggregates characteristic of Alzheimer’s.