Diets Enriched in Fish-Oil or Seal-Oil have Distinct Effects on Lipid Levels and Peroxidation in BioF1B Hamsters

Aim: Fish-oil omega-3 polyunsaturated fatty acids (n-3 PUFAs) are mostly esterified to the sn-2 position of triglycerides, while in seal-oil triglycerides, these are mostly esterified to the sn-1 and -3 positions. We investigated whether fish-oil and seal-oil feeding has a different effect on the regulation of lipid metabolism and oxidative stress in BioF1B hamsters. Methods: BioF1B hamsters were fed high fat diets rich in fish-oil or seal-oil for 4 weeks, and fasted for 14 hours prior to blood and tissue collection. Results: Plasma and hepatic lipids and lipid peroxidation levels were significantly lower in seal-oil-fed hamsters as compared to those fed fish-oil. There was a selective hindrance of clearance of lipids in fish-oil-fed hamsters as reflected by higher levels of plasma apoB48. Conclusion: Differences in the fatty acid composition and positional distribution of n-3 PUFAs in triglycerides of fish-oil and seal-oil are suggested to trigger metabolic differences.