Western versus Omega‐3 Based Diets Differentially Alter Key Brain Fatty Acid Transport Genes

Abstract

The Western high‐fat diet is associated with poor health outcomes, while omega‐3 fatty acids supplementation has shown to mitigate metabolic imbalances seen with the Western diet. Growing evidence shows diet impacts cerebrovascular and brain health. Understanding of how the percentage and type of fat in the diet affects brain and microvascular expression of fatty acid transport genes remains limited.PURPOSETo elucidate the dietary impact of fat type (lard vs. fish oil) and percentage of fat (10% vs 41%) on metabolic parameters and expression of key genes associated with transport and actions of fatty acids in the brain and microvasculature.METHODS8‐week male C57Bl/6 mice (n = 12/group) were randomized to one of four treatment groups: 10% kcal lard,10% kcal fish (menhaden) oil 41% kcal lard or 41% kcal fish oil ad libitum for 32 weeks. Total plasma cholesterol, LDL, HOMA‐IR, glucose, and triglycerides were measured at the conclusion of the study. Cortical (cerebral cortex) and subcortical (hippocampus, amygdala, thalamus, caudate) brain tissues were harvested and mRNA expression (Mfsd2a, Cd36, ApoE, Abca1, Ppara, Pparg) was measured via RT‐qPCR relative to the 10% lard diet. Mfsd2a protein expression was assessed via Western blot.RESULTSMean total cholesterol, LDL, glucose and HOMA‐IR significantly differed with the type of fat, the percentage of fat, and their interaction. The mean LDL, total cholesterol, glucose and HOMA‐IR were significantly higher in mice receiving 41% lard compared to mice receiving other diets. Mean cortical Mfsd2a protein expression significantly differed with the percentage of fat and the interaction between the type and percentage of fat. Mean Mfsd2a protein expression was significantly higher in all other diet groups compared to 10% lard. Mean cortical Mfsd2a mRNA expression differed with the type of fat. Mice receiving fish oil had higher‐fold Mfsd2a mRNA expression compared to those receiving lard. Mean cortical Pparg mRNA expression significantly differed with the type and percentage of fat. Mice receiving fish oil or 41% fat had higher‐fold Pparg expression compared to mice receiving lard or 10% fat, respectively.CONCLUSIONSFindings showed that the type and percentage of fat could play a critical role in the metabolic profile and expression of genes involved in the transport or action of fatty acids in the cerebrovasculature and/or brain.Support or Funding InformationThis work was supported by the National Institutes of Health, National Institute of Neurological Disorders and Stroke (Grant: R21NS090282).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.