The development of obesity is characterized by the metabolic overload of tissues and subsequent organ inflammation. The health effects of krill oil (KrO) on obesity-associated inflammation remain largely elusive, because long-term treatments with KrO have not been performed to date. Therefore, we examined the putative health effects of 28 weeks of 3% (w/w) KrO supplementation to an obesogenic diet (HFD) with fat derived mostly from lard. The HFD with KrO was compared to an HFD control group to evaluate the effects on fatty acid composition and associated inflammation in epididymal white adipose tissue (eWAT) and the liver during obesity development. KrO treatment increased the concentrations of EPA and DHA and associated oxylipins, including 18-HEPE, RvE₂ and 14-HDHA in eWAT and the liver. Simultaneously, KrO decreased arachidonic acid concentrations and arachidonic-acid-derived oxylipins (e.g., HETEs, PGD₂, PGE₂, PGF₂α, TXB₂). In eWAT, KrO activated regulators of adipogenesis (e.g., PPARγ, CEBPα, KLF15, STAT5A), induced a shift towards smaller adipocytes and increased the total adipocyte numbers indicative for hyperplasia. KrO reduced crown-like structures in eWAT, and suppressed HFD-stimulated inflammatory pathways including TNFα and CCL2/MCP-1 signaling. The observed eWAT changes were accompanied by reduced plasma leptin and increased plasma adiponectin levels over time, and improved insulin resistance (HOMA-IR). In the liver, KrO suppressed inflammatory signaling pathways, including those controlled by IL-1β and M-CSF, without affecting liver histology. Furthermore, KrO deactivated hepatic REL-A/p65-NF-κB signaling, consistent with increased PPARα protein expression and a trend towards an increase in IkBα. In conclusion, long-term KrO treatment increased several anti-inflammatory PUFAs and oxylipins in WAT and the liver. These changes were accompanied by beneficial effects on general metabolism and inflammatory tone at the tissue level. The stimulation of adipogenesis by KrO allows for safe fat storage and may, together with more direct PPAR-mediated anti-inflammatory mechanisms, attenuate inflammation.

As an essential nutrient, the organic water-soluble compound choline is important for human health. Choline is required for numerous biological processes, including the synthesis of neurotransmitters, and it is an important prerequisite for structural integrity and the functioning of cells. A choline-rich diet provides crucial choline sources, yet additional choline dietary supplements might be needed to fully meet the body’s requirements. Dependent on the structure of choline in different sources, absorption and metabolism may differ and strongly impact the bioavailability of circulating choline. This study in healthy volunteers aimed to compare the pharmacokinetics of free choline and of selected choline metabolites between the single dose intake of phosphatidylcholine, present in SuperbaBoost^TM krill oil, and choline bitartrate salt. Results demonstrate that albeit free choline levels in plasma were comparable between both choline sources, peak choline concentration was reached significantly later upon intake of SuperbaBoost^TM. Moreover, the occurrence of choline metabolites differed between the study products. Levels of the biologically important metabolites betaine and dimethylglycine (DMG) were higher, while levels of trimethylamine N-oxide (TMAO) were substantially lower upon intake of SuperbaBoost^TM compared to choline bitartrate.

High serum levels of cholesterol, in particular low-density lipoprotein cholesterol, are considered a significant risk factor for development of cardiovascular disease. Therefore, rigorous treatment regimens with statins and other pharmaceuticals have been used extensively to reduce elevated cholesterol levels. Literature data have not clearly concluded whether long-chain omega-3 fatty acids reduce, increase or leave circulating cholesterol unaffected. In the present study a novel krill-oil derived preparation of omega-3 rich phospholipids, mainly phosphatidylcholine, was administered orally at increasing doses for 12 weeks to dyslipidemic non-human primates, and cholesterols and several other risk factors for cardiovascular disease were measured before, during and after treatment. Six dyslipidemic non-human primates suffering from naturally occurring diabetes type-2 were included, three in a vehicle control group and three being treated with the omega-3 rich phospholipid preparation. The control and test items were given daily by gavage and the doses of the test item were 50, 150 and 450 mg phospholipids/kg/day. Each dose level was given for 4 weeks. Plasma concentrations of the omega-3 fatty acids were measured in connection with change in dose and the omega-3 index in erythrocytes was determined bi-weekly. Blood lipids, apolipoproteins and diabetes, inflammatory and safety biomarkers were determined either weekly, biweekly or every 4 weeks. For the blood lipids and apolipoproteins, control-adjusted mean values are presented while absolute values are presented for the other parameters. Due to the low number of animals in each group, no statistical analyses were done. The only detectable effects measured during dosing with the lowest dose were an increase in HDL-cholesterol and apolipoprotein A1. The intermediate and high doses decreased total cholesterol, LDL-cholesterol, apolipoprotein B100 and triglycerides and increased HDL-cholesterol and apolipoprotein A1. No effects were seen on the diabetes and inflammatory markers and on safety biomarkers. The results indicate that the omega-3 rich phospholipid preparation had a positive impact on cardiovascular disease risk factors by reducing total cholesterol, LDL-cholesterol and triglycerides and increasing HDL-cholesterol. These findings justify further investigations of this preparation in animal models of dyslipidemia and, provided the current findings are confirmed, in human trials.

A commonly used measure to reflect the intake of the long-chain omega-3 fatty acids EPA and DHA is the omega-3 index, defined as the sum of EPA + DHA as % of total fatty acids in erythrocyte membrane. When the omega-3 index changes it follows that the relative fractions of other fatty acids in the membrane are also changed. In the present study, increasing doses of a preparation of omega-3 rich phospholipids extracted from krill oil were administered orally to non-human primates for 12 weeks and the time course of EPA, DHA and 22 other fatty acids in erythrocytes was determined bi-weekly during treatment and for 8 weeks after cessation of treatment. Plasma concentrations of six endocannabinoid-type mediators being downstream metabolites of some fatty acids analyzed in erythrocytes were also determined. Six diabetic, dyslipidemic non-human primates were included, three in a vehicle control group and three being treated with the omega-3 rich phospholipid preparation. The vehicle control and test items were given daily by gavage and the test item doses were 50, 150 and 450 mg phospholipids/kg/day. Each dose level was given for four weeks. Blood was sampled at baseline and thereafter bi-weekly. Fatty acids were determined in erythrocytes by methylation followed by gas-chromatography. Endocannabinoids and endocannabinoid-like mediators were analyzed in plasma by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry. The treatment resulted in a dose-related increase in the fraction of EPA and DHA in erythrocyte membranes and a dose-related decrease of other poly-unsaturated fatty acids, in particular omega-6 polyunsaturated fatty acids. Erythrocyte concentrations of saturated fatty acids remained unchanged throughout the experiment. Plasma concentrations of endocannabinoids and endocannabinoid-like mediators changed accordingly as those being downstream arachidonic acid decreased, downstream of the saturated palmitic and oleic acids remained unchanged while a downstream EPA metabolite increased. Increasing the omega-3 index by administering an omega-3 rich phospholipid extracted from krill oil did not alter the ratio of unsaturated vs. saturated fatty acids in the erythrocyte membranes but only the relative concentrations of unsaturated fatty acids, in particular unsaturated omega-6 fatty acids. Concentrations of saturated fatty acids remained unchanged.