Structured Triacylglycerols with Docosahexaenoic Acid (DHA) at the sn -2 Position Increase DHA Incorporation in Brown Adipose Tissue, but not in White Adipose Tissue, of Hamsters

In this study, we hypothesized that incorporation of docosahexaenoic acid (DHA, 22:6 n -3) across adipose tissues will be higher when it is ingested as triacylglycerols (TAG) structured at the sn -2 position, which enhances efficacy of DHA supplementation and protective actions against obesity. Ten-week old Golden Syrian male hamsters were randomly allocated to 4 dietary groups with 10 animals each: linseed oil (LSO; control group), fish oil (FO), fish oil ethyl esters (FO-EE) and structured DHA at the sn -2 position of TAG (DHA-SL). After 12 weeks, there were no variations in body composition parameters, including subcutaneous white adipose tissue (WAT), retroperitoneal WAT and brown adipose tissue (BAT) mass or plasma insulin, leptin and adiponectin across dietary treatments. In opposition to the large variations found for fatty acid composition in both depots of WAT, BAT was less responsive to diets. Even so, DHA and eicosapentaenoic acid (EPA, 20:5 n -3) were not found in subcutaneous and retroperitoneal WAT in contrast to DHA, which was incorporated successfully in BAT reaching the highest percentage in DHA-SL fed hamsters. The principal component analysis of plasma hormones and fatty acids discriminated BAT from WAT and set apart 3 clusters matching 3 fat depots pointing toward an individual signature on fatty acids deposition. In turn, discrimination of dietary treatments within each adipose tissue was unattainable. Taken together, structured sn -2 position DHA-containing TAG, relative to commercially fish oils, had no impact neither on fat depots weight nor on systemic hormones, but improved DHA incorporation in BAT due to its higher bioavailability.