Organ-Specific Responses to Chronic High-Fat Diets in Mice: Insights into Phospholipid Fatty Acid Distribution

<b>Background/Objectives</b>: This research aimed to investigate phospholipid fatty acid (PLFA) distribution in the brain, kidneys, and white adipose tissue (WAT) and lipid profiles in response to high-fat diets. <b>Methods</b>: Adult female C57BL/6 mice were fed high-fat diets containing 25% linseed, palm, or sunflower oil for 100 days. The fatty acid composition of dietary oils and tissue PL were analyzed using gas-liquid chromatography. <b>Results</b>: Linseed oil increased <i>n</i>-3 polyunsaturated fatty acids (PUFAs) with subsequent conversion into long-chain <i>n</i>-3 PUFAs in the brain and kidney PL, while only alpha-linolenic acid was elevated in WAT. Palm and sunflower oils resulted in unique PLFA distributions in the kidneys and WAT. Palm oil raised linoleic acid without conversion to pro-inflammatory <i>n</i>-6 PUFAs. Sunflower oil increased saturated palmitic acid, as opposed to the rise in monounsaturated oleic acid. Linseed oil also significantly improved lipid profiles, reducing LDL and increasing HDL levels while enhancing cardiovascular indices. <b>Conclusions</b>: This study demonstrates that dietary oils significantly impact organ-specific PLFA profiles, with linseed oil enriching brain and renal <i>n</i>-3 PUFAs, while palm and sunflower oils induce distinct modifications in the kidney and WAT. Moreover, linseed oil offers notable cardioprotective benefits due to the favorable lipid profile changes. These findings highlight the importance of dietary fat selection in achieving balanced lipid metabolism and suggest that diverse oil combinations may be essential for optimizing health outcomes.