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The metabolic syndrome (MetS) is a cluster of cardiovascular risk factors including obesity, insulin resistance (IR) and dyslipidaemia. Consumption of a high-fat diet (HFD) enriched in SFA leads to the accumulation of ceramide (Cer), the central molecule in sphingolipid metabolism. Elevations in plasma and tissue Cer are found in obese individuals, and there is evidence to suggest that Cer lipotoxicity contributes to the MetS. EPA and DHA have shown to improve MetS parameters including IR, inflammation and hypertriacylglycerolaemia; however, whether these improvements are related to Cer is currently unknown. This review examines the potential of EPA and DHA to improve Cer lipotoxicity and MetS parameters including IR, inflammation and dyslipidaemia in vitro and in vivo. Current evidence from cell culture and animal studies indicates that EPA and DHA attenuate palmitate- or HFD-induced Cer lipotoxicity and IR, whereas evidence in humans is greatly lacking. Overall, there is intriguing potential for EPA and DHA to improve Cer lipotoxicity and related MetS parameters, but more research is warranted.

Nutritional condition during early life could have long lasting effects on metabolism, growth trajectory and ultimately ecological fitness. We examined effects of Artemia nauplii enriched with eicosapentaenoic acid (EPA; C20:5n3) and docosahexaenoic acid (DHA; C22:6n3) on fatty acid profile, digestive enzyme activity, energy density, aerobic scope, growth and survival in age-0 Lake Sturgeon (Acipenser fulvescens). Four diets were used in the study: 1) control (absence of EPA and DHA): freshly hatched Artemia nauplii, 2) low DHA: Artemia enriched with Chlorella vulgaris , 3) high DHA: Artemia enriched with Red AlgaMac and 4) time-control: Artemia left for the time to match growth that would occur during the enrichment. At 20 days post hatch (dph), fish were fed one of four diets three times a day ad libitum for 29 days after which all fish were fed the same diet of bloodworm twice a day ad libitum until the end of the experiment, which included a simulated overwintering event for 45 days at 3 °C. Fish were sampled after 24 days of feeding the aforementioned diets, as well as before and after the simulated overwintering event at 145 and 190 dph, respectively. Fish fed the high DHA diet did not change the measured parameters compared to fish fed the control diet after 24 days of feeding; however, before overwintering fish fed high DHA showed higher lipase activity (p = 0.01) compared to the control group and significantly increased body mass when temperature decreased (p < 0.05). Further, fish fed the high DHA diet showed a substantially lower mortality than fish fed the control diet following the diet transition from Artemia to bloodworm (44%; p < 0.05). Our results suggest the importance of EPA and DHA during early life on growth and survival, which could be used to improve post-release survival rates in conservation aquaculture of Lake Sturgeon, a species at risk or endangered across its natural range. • High DHA diet significantly altered the fatty acid composition of whole body. • High DHA diet significantly increased growth when temperature was declining. • High DHA diet significantly reduced mortality by 44% after the first diet transition. [ABSTRACT FROM AUTHOR]

Abstract: The objective was to determine the effect of long-term dietary supplementation of two types of fish oil on lipid composition and steroidogenesis in adult pig testis. Twenty-four Duroc boars, aged 204.5 ± 9.4 d (body weight 128.1 ± 16.7 kg) received daily 2.5 kg of an iso-caloric basal diet supplemented with: 1) 62 g of hydrogenated animal fat (AF); 2) 60 g of menhaden oil (MO) containing 16% of eicosapentaenoic acid (EPA) and 18% of docosahexaenoic acid (DHA); or 3) 60 g of tuna oil (TO) containing 7% of EPA and 33% of DHA. After these diets were consumed for 7 mo, testicular hormones, phospholipid content, and fatty acid composition of individual phospholipids in testis were determined. Body and reproductive organ weights were not significantly affected by dietary treatments. Testicular tissue from boars fed a TO diet, followed by those receiving MO and AF diets, had the lowest level of phosphatidylethanolamine (TO < MO < AF; P < 0.01) but the highest sphingomyelin (TO > MO > AF; P < 0.01). For each phospholipid, boars fed either the MO or TO diet had increased total omega-3 fatty acids, particularly DHA (P < 0.01), by reciprocal replacement of total omega-6 fatty acids (20:4n-6, 22:5n-6). The MO diet increased EPA more than the other diets. Testicular concentrations of testosterone and estradiol were lower in boars fed a TO diet than a MO diet (P < 0.02). In conclusion, long-term dietary supplementation of fish oil, regardless of the EPA/DHA ratio, modified the fatty acid compositions in testis and affected steroid production of healthy adult boars, which may represent a promising models for future studies on fertility. [Copyright &y& Elsevier]