Long-Term Palmitoleic Acid-Enriched Marine Oil Ingestion Attenuates Adiposity and Glucose Intolerance in Cafeteria Diet-Fed Mice

Palmitoleic acid (16:1n-7) has been associated with metabolic regulation, but the effects of long-term supplementation during consumption of a complex obesogenic diet remain poorly defined. We investigated whether palmitoleic acid-enriched marine oil modifies adiposity, glucose homeostasis, lipid metabolism, and tissue fatty-acid composition in mice exposed to a cafeteria diet. Male C57BL/6 mice were assigned in a 2 × 2 factorial design (Diet × Oil) to standard diet (SD), cafeteria diet (CAF), standard diet plus oil (SDO), or cafeteria diet plus oil (CAFO) for 16 weeks. Supplemented animals received 1 g/kg body mass/day of oil containing 558 mg/g palmitoleic acid ethyl ester. Diet × Oil interactions were observed for adiposity (p = 0.0004), adipocyte area (p = 0.0062), glucose tolerance (p = 0.0009), and plasma triacylglycerol (p = 0.0070). Compared with CAF, CAFO mice had lower adiposity, adipocyte area, glucose area under the curve, and plasma triacylglycerol, whereas hepatic lipid concentrations were not improved. Supplementation substantially increased palmitoleate in red blood cells and adipose tissue. These findings demonstrate substantial incorporation of supplemented palmitoleate and selective attenuation of metabolic alterations associated with long-term cafeteria-diet consumption.