Dementia is a growing concern worldwide, with the number of people predicted to have the condition rising to over 150 million by 2050. Lifestyle factors such as lack of exercise, an unhealthy diet, smoking, and alcohol consumption can increase the risk of cognitive decline and Alzheimer’s disease. Studies have shown that a high intake of saturated fat is a major risk factor for Alzheimer’s, and obesity can also increase the risk of developing the disease. Nutrition plays an important role in brain health and the risk of Alzheimer’s later in life.
A recent study in mice has uncovered a molecular mechanism that could explain why a high-fat diet increases the risk of Alzheimer’s. Researchers used transgenic APP/PS1 mice that develop characteristics of Alzheimer’s disease and fed them either a normal diet or a high-fat diet for 6 months. The mice on the high-fat diet gained more weight and showed worse glucose and insulin metabolism. RNA extracted from their serum, cortex, and hippocampus showed changes in miRNA related to neurodegeneration, beta-amyloid production, tau protein production, and brain inflammation, all of which are markers of Alzheimer’s disease.
While these findings shed light on how a high-fat diet may affect insulin-resistant microRNAs and impact memory and cognition-related brain areas, there are limitations in the study. The researchers only investigated male mice and did not look at the role of fat cells, other organs, and other brain areas. Results in mice do not always translate to humans, so more research in representative populations is needed to fully understand the impact of diet on Alzheimer’s disease. The Alzheimer’s Association is currently funding several studies investigating the impact of diet, diabetes, obesity, and neuroinflammation in the development of Alzheimer’s, dementia, and cognitive decline.
Lead researcher Mònica Bulló from the Department of Biochemistry and Biotechnology at URV stated that the study results offer new targets for the possible prevention and treatment of Alzheimer’s. The findings may explain the relationship between obesity, type 2 diabetes, and the onset of the disease. While the study provides valuable insights, it is important to note that animal models of Alzheimer’s do not replicate the disease in humans exactly. Human studies are essential to validate the findings and understand the impacts and outcomes of a high-fat diet on people living with or at risk for Alzheimer’s.
Healthful diets such as the Mediterranean, DASH, and MIND diets have been shown to help reduce the risk of Alzheimer’s disease, according to the National Institutes of Health. This study provides further evidence that limiting fat intake may be beneficial for cognitive function. However, more research is needed to determine whether the mechanisms observed in mice also apply to humans. Understanding the impacts of a high-fat diet on Alzheimer’s requires human studies in representative populations. The findings from this study underscore the importance of investigating the role of diet, diabetes, obesity, and neuroinflammation in the development of Alzheimer’s, dementia, and cognitive decline.
