Comparative effects of high oleic acid vs high mixed saturated fatty acid obesogenic diets upon PUFA metabolism in mice

Authors: Picklo, Matthew; Idso, Joseph; SEEGER, DREW - University Of North Dakota; AUKEMA, HAROLD - University Of Manitoba; MURPHY, ERIC - University Of North Dakota

Submitted to: Prostaglandins Leukotrienes and Essential Fatty Acids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2017
Publication Date: 4/1/2017
Publication URL: https://handle.nal.usda.gov/10113/5832857
Citation: Picklo, M.J., Idso, J.P., Seeger, D., Aukema, H., Murphy, E. 2017. Comparative effects of high oleic acid vs high mixed saturated fatty acid obesogenic diets upon PUFA metabolism in mice. Prostaglandins Leukotrienes and Essential Fatty Acids. 119:25-37.

Interpretive Summary: Saturated fatty acids (SFA) and oleic acid are the most common fatty acids consumed in the American diet. Emerging evidence shows that the type of fatty acids that comprise our dietary fat intake impact the development of obesity and outcomes including fatty liver and insulin resistance. Polyunsaturated fatty acids (PUFA) are dietary fatty acids that are important to cellular function and are converted to compounds with pro-inflammatory and anti-inflammatory properties. In this work, we examined how diets made with oleic acid vs SFAs change PUFA metabolism in obese mice. The SFA used was a mixture of fatty acids derived from coconut oil and milk fat whereas oleic acid was derived from high oleic sunflower oil. Our experiments, performed in obese mice, indicate that an obesity-causing diet high in oleic acid can reduce PUFA levels and PUFA metabolites and can cause fatty liver. These effects were not observed in mice fed diets made with the high levels of SFA. Our data indicate that SFA and oleic acid have different effects on the metabolism of PUFA and the development of fatty liver. Our data indicate that more research is needed to determine if and how specific SFA may have beneficial health effects.

Technical Abstract: Emerging evidence indicates that the fatty acid composition of obesogenic diets influences physiologic outcomes. There are scant data regarding how the content of non-essential fatty acids like monounsaturated fatty acids (MUFA) and saturated fatty acids (SFAs) impact the metabolism of polyunsaturated fatty acids (PUFAs). In this work, we tested the hypothesis that obesogenic diets enriched in oleic acid (OA; 18:1n-9) reduce polyunsaturated fatty acid (PUFA) levels vs an obesogenic diet enriched in SFAs. Adult male mice were fed for eight weeks either (1) a control 16% fat energy (en) diet with 5.7% en OA and 4.4% en SFA, (2) a 50% fat en diet with 33% en OA and 9.9% en SFA, or (3) a 50% en diet with a high SFA diet with 33% en SFA and 9.1% en OA. Dietary levels and intake of linoleic acid (LA; 18:2n-6) and a-linolenic acid (ALA;18:3n-3) were constant between the experimental groups. Several peripheral organs (liver, heart, kidney, and adipose) were analyzed for lipid composition and oxylipin analysis was performed for liver and adipose. Our data demonstrate that a high OA diet reduced tissue content of LA and ALA( = 30%) in phospholipid and neutral lipid fractions, reduced the content of some LA-derived and ALA-derived oxylipins in liver and adipose, and conversely, elevated hepatic content of PGF2a. In all tissues examined, except for adipose, levels of arachidonic acid (ARA; 20:4n-6) and docosahexaenoic acid (DHA; 22:6n-3) were either elevated or unaffected by the obesogenic diets. Our data indicate that the non-essential fatty content of obesogenic diets impacts PUFA content in peripheral tissues and influences the levels of bioactive oxylipins.