Basic nutritional investigationHigh-fat diets rich in ω-3 or ω-6 polyunsaturated fatty acids have distinct effects on lipid profiles and lipid peroxidation in mice selected for either high body weight or leanness

ObjectiveThe aim of the study is to determine the response of muscle lipid peroxidation and the fatty-acid profile of three groups of mice-high body weight (DU6) obesity-prone mice, high treadmill performance (DUhTP) lean mice, and unselected control mice (DUK) fed high-fat diets (HFDs) rich in ω-3 or ω-6 polyunsaturated fatty acids (PUFA).MethodsThe isocaloric HFDs were enriched with either ω-3 PUFA (27% fish oil, ω-3 HFD) or ω-6 PUFA (27% sunflower oil, ω-6 HFD), and the control group was fed standard chow (7.2% fat). Statistical calculations were done with procedure GLM of SAS.ResultsAs expected, the ω-3 and ω-6 PUFA-rich HFDs showed significant effects on fatty-acid concentrations of skeletal muscle in all three lines of mice compared with the standard chow. The investigations of muscle lipid peroxidation revealed that the ω-3 PUFA-rich HFD caused the highest lipid peroxidation values in muscle of lean DUhTP mice and unselected control DUK mice. However, lower lipid peroxidation levels were observed in the obesity-prone DU6 mice. In contrast, the ω-6 PUFA-rich HFD did not influence lipid peroxidation in muscle of any of the different lines of mice. The present study suggests that a higher overall antioxidant capacity in the muscle tissue of obesity-prone DU6 mice may lead to lower levels of reactive oxygen species formation by ω-3 PUFA-rich HFDs in comparison with lean DUhTP mice.ConclusionThese studies raise the possibility that obesity per se may be protective against oxidative damage when high ω-3 PUFA diets are used.