Fish oil

About: Fish oil is a research topic. Over the lifetime, 9887 publications have been published within this topic receiving 367953 citations. The topic is also known as: fish oils & Fish oil.

Effect of low-to-moderate amounts of dietary fish oil on neutrophil lipid composition and function.

Abstract: Although essential to host defense, neutrophils are also involved in numerous inflammatory disorders including rheumatoid arthritis. Dietary supplementation with relatively large amounts of fish oil [containing >2.6 g eicosapentaenoic acid (EPA) plus 1.4 g docosahexaenoic acid (DHA) per day] can attenuate neutrophil functions such as chemotaxis and superoxide radical production. In this study, the effects of more moderate supplementation with fish oil on neutrophil lipid composition and function were investigated. The rationale for using lower supplementary doses of fish oil was to avoid adverse gastrointestinal problems, which have been observed at high supplementary concentrations of fish oil. Healthy male volunteers aged <40 yr were randomly assigned to consume one of six dietary supplements daily for 12 wk (n = 8 per treatment group). The dietary supplements included four different concentrations of fish oil (the most concentrated fish oil provided 0.58 g EPA plus 1.67 g DHA per day), linseed oil, and a placebo oil. The percentages of EPA and DHA increased (both P < 0.05) in neutrophil phospholipids in a dose-dependent manner after 4 wk of supplementation with the three most concentrated fish oil supplements. No further increases in EPA or DHA levels were observed after 4 wk. The percentage of arachidonic acid in neutrophil phospholipids decreased (P < 0.05) after 12 wk supplementation with the linseed oil supplement or the two most concentrated fish oil supplements. There were no significant changes in N-formyl-met-leu-phe-induced chemotaxis and superoxide radical production following the dietary supplementations. In conclusion, low-to-moderate amounts of dietary fish oil can be used to manipulate neutrophil fatty acid composition. However, this may not be accompanied by modulation of neutrophil functions such as chemotaxis and superoxide radical production.

n-3 Fatty Acids Preserve Insulin Sensitivity In Vivo in a Peroxisome Proliferator–Activated Receptor-α–Dependent Manner

Abstract: Recent studies have suggested that n-3 fatty acids, abundant in fish oil, protect against high-fat diet-induced insulin resistance through peroxisome proliferator-activated receptor (PPAR)-alpha activation and a subsequent decrease in intracellular lipid abundance. To directly test this hypothesis, we fed PPAR-alpha null and wild-type mice for 2 weeks with isocaloric high-fat diets containing 27% fat from either safflower oil or safflower oil with an 8% fish oil replacement (fish oil diet). In both genotypes the safflower oil diet blunted insulin-mediated suppression of hepatic glucose production (P < 0.02 vs. genotype control) and PEPCK gene expression. Feeding wild-type mice a fish oil diet restored hepatic insulin sensitivity (hepatic glucose production [HGP], P < 0.002 vs. wild-type mice fed safflower oil), whereas in contrast, in PPAR-alpha null mice failed to counteract hepatic insulin resistance (HGP, P = NS vs. PPAR-alpha null safflower oil-fed mice). In PPAR-alpha null mice fed the fish oil diet, safflower oil plus fish oil, hepatic insulin resistance was dissociated from increases in hepatic triacylglycerol and acyl-CoA but accompanied by a more than threefold increase in hepatic diacylglycerol concentration (P < 0.0001 vs. genotype control). These data support the hypothesis that n-3 fatty acids protect from high-fat diet-induced hepatic insulin resistance in a PPAR-alpha-and diacylglycerol-dependent manner.