Can the dietary fat type facilitate memory impairments in adulthood? A comparative study between Mediterranean and Western-based diet in rats

J Nutr Biochem. 2018 Sep:59:104-113. doi: 10.1016/j.jnutbio.2018.05.015. Epub 2018 Jun 7.

Abstract

A balanced intake of fatty acids (FA) of both omega-6 (n-6) and -3 (n-3) series is essential for memory. The Mediterranean diet (MD), rich in n-3 polyunsaturated FA (PUFA) and low n-6/n-3 PUFA ratio, has shown beneficial influences on health. Inversely, the Western diet contains saturated fats, including hydrogenated vegetable fat (HVF, rich in trans fat) and interesterified fat (IF), making the n-6/n-3 PUFA ratio high. Due to the health impairments caused by HVF, it has been replaced by IF in processed foods. We compared an MD (balanced n-6/n-3 PUFA ratio) with Western diets 1 (WD1, rich in trans fat) and 2 (WD2, rich in IF) on memory process per se and following scopolamine (SCO) administration, which induces amnesia in rats. While MD exerted protective effects, WD1 and WD2 showed declined memory per se, showing higher susceptibility to SCO-induced memory deficits. In addition, WD1 and WD2 showed increased proinflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-1β, IL-6] and decreased anti-inflammatory cytokines (IL-10) in plasma. IL-1β was higher in the hippocampus of WD1, which was reflected on histological assessments. Significant correlations between cognitive decline and inflammatory markers reinforce our hypothesis: MD-like fats may act preventively on cognitive loss, while WD-like fats may facilitate this.

Keywords: Inflammatory cytokines; Interesterified fat; Memory impairments; Scopolamine; trans fat.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers / metabolism
  • Body Weight / drug effects
  • Cytokines / blood
  • Cytokines / metabolism
  • Diet, Mediterranean*
  • Diet, Western*
  • Dietary Fats / adverse effects*
  • Fatty Acids, Omega-3 / pharmacology
  • Fatty Acids, Omega-6 / pharmacology
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • Hippocampus / pathology
  • Inflammation / etiology
  • Male
  • Memory Disorders / etiology*
  • Rats, Wistar
  • Scopolamine / adverse effects

Substances

  • Biomarkers
  • Cytokines
  • Dietary Fats
  • Fatty Acids, Omega-3
  • Fatty Acids, Omega-6
  • Scopolamine