High-Fat Diet Linked to Alzheimer’s Through Molecular Changes

Summary: A new study uncovered how diets high in saturated fats contribute to the development of Alzheimer’s disease by affecting crucial molecular markers in the brain and blood. The research utilized mouse models to investigate the impact of such diets on the expression of miRNAs related to insulin regulation, revealing significant metabolic deterioration and brain inflammation.

These molecular changes correlate with early onset Alzheimer’s, providing insights into the connections between diet, obesity, type 2 diabetes, and neurodegenerative diseases. The findings offer potential new targets for preventing and treating Alzheimer’s.

Key Facts:

  1. Impact on miRNAs: The research identified changes in insulin-related miRNAs in both plasma and brain tissues, which are linked to key Alzheimer’s processes like β-amyloid plaque accumulation and tau protein overproduction.
  2. Metabolic Deterioration: Mice on a high-saturated fat diet showed increased body weight and reduced glucose and insulin response, mirroring conditions seen in obesity and type 2 diabetes.
  3. Potential for Dietary Intervention: The study highlights the importance of diet in Alzheimer’s prevention and opens avenues for using dietary strategies to combat neurodegenerative diseases.

Source: URV

A study led by the URV has revealed the mechanism behind the link between a diet high in saturated fats and Alzheimer’s disease. The research focused on how this kind of diet affects certain molecules found in the blood and in other tissues such as the brain that act as markers and regulators of the disease.

The study was headed by Mònica Bulló, professor at the Department of Biochemistry and Biotechnology and member of the Metabolic Health and Nutrition unit and the Environmental, Food and Toxicological Technology Centre (TecnATox) of the URV, in collaboration with the Pere Virgili Health Research Institute (IISPV), CIBERobn and the University of Barcelona.

This shows a burger.
The team examined changes in insulin-related miRNAs in mouse models predisposed to Alzheimer’s not on a diet low in saturated fats. Credit: Neuroscience News

The results have been published in the journal Nutrients.

The research was conducted on mice models who developed Alzheimer’s disease in adulthood. Previous studies in these animals had already shown that after a diet high in saturated fats the mice developed Alzheimer’s much earlier than mice on a conventional diet. However, the mechanisms that led to the onset of Alzheimer’s remained unknown. That is, until now.

The researchers analysed the expression of 15 miRNAs, small molecules of RNA that play a crucial role in genetic regulation in both plasma and brain tissues. The team examined changes in insulin-related miRNAs in mouse models predisposed to Alzheimer’s not on a diet low in saturated fats.

The results demonstrated that their metabolism worsened after being on this diet for six months: their body weight increased significantly and their response to glucose and insulin decreased. These same characteristics can also be found in people with obesity or type 2 diabetes.

Furthermore, researchers found changes to various miRNAs in both the blood and the brain. These changes were related to processes that can cause brain damage, such as the accumulation of β-amyloid plaques (protein deposits that form in the brain and which are markers of Alzheimer’s), excessive production of the tau protein (which can damage brain cells when it gets out of control) and inflammation in the brain.

“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”, said researcher Mònica Bulló

The study not only provides new data on how a high-fat diet can affect the health of the brain, but also opens the door to future research into dietary strategies as a means of treating Alzheimer’s.

The results underline the importance of a balanced diet in preventing neurodegenerative diseases and highlight miRNAs as targets for therapeutic interventions.

About this Alzheimer’s disease and diet research news

Author: Montse Guasch
Source: URV
Contact: Montse Guasch – URV
Image: The image is credited to Neuroscience News

Original Research: Open access.
Effects of a High-Fat Diet on Insulin-Related miRNAs in Plasma and Brain Tissue in APPSwe/PS1dE9 and Wild-Type C57BL/6J Mice” by Mònica Bulló et al. Nutrients


Effects of a High-Fat Diet on Insulin-Related miRNAs in Plasma and Brain Tissue in APPSwe/PS1dE9 and Wild-Type C57BL/6J Mice

Insulin resistance (IR)-related miRNAs have been associated with the development and progression of Alzheimer’s disease (AD). The dietary modulation of these miRNAs could become a potential strategy to manage AD.

The aim of this study was to evaluate the effect of a high-fat diet (HFD), which aggravates AD-related pathogenic processes, on serum, cortex and hippocampus IR-related miRNA expression. C57BL/6J WT and APPSwe/PS1dE9 mice were fed either an HFD or a conventional diet till 6 months of age.

The mice fed with the HFD showed a significant increase in body weight and worsening glucose and insulin metabolism. miR-19a-3p was found to be up-regulated in the cortex, hippocampus and serum of APP/PS1 mice and in the serum and hippocampus of WT mice fed with the HFD. miR-34a-5p and miR-146a-5p were up-regulated in the serum of both groups of mice after consuming the HFD. Serum miR-29c-3p was overexpressed after consuming the HFD, along with hippocampal miR-338-3p and miR-125b-5p, only in WT mice.

The HFD modulated the expression of peripheral and brain miRNAs related to glucose and insulin metabolism, suggesting the potential role of these miRNAs not only as therapeutic targets of AD but also as peripheral biomarkers for monitoring AD.

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