UBC Faculty Research and Publications

Phospholipids from herring roe improve plasma lipids and glucose tolerance in healthy, young adults Bjørndal, Bodil; Strand, Elin; Gjerde, Jennifer; Bohov, Pavol; Svardal, Asbjørn; Diehl, Bernd W; Innis, Sheila M; Berger, Alvin; Berge, Rolf K May 17, 2014

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata


52383-12944_2014_Article_1073.pdf [ 283.68kB ]
JSON: 52383-1.0132566.json
JSON-LD: 52383-1.0132566-ld.json
RDF/XML (Pretty): 52383-1.0132566-rdf.xml
RDF/JSON: 52383-1.0132566-rdf.json
Turtle: 52383-1.0132566-turtle.txt
N-Triples: 52383-1.0132566-rdf-ntriples.txt
Original Record: 52383-1.0132566-source.json
Full Text

Full Text

RESEARCH Open AccessPhospholipids from herring roe improve plasmalipids and glucose tolerance in healthy,young adultsBodil Bjørndal1*, Elin Strand1, Jennifer Gjerde1,2, Pavol Bohov1, Asbjørn Svardal1, Bernd WK Diehl4, Sheila M Innis3,Alvin Berger5,6 and Rolf K Berge1,7AbstractBackground: Herring roe is an underutilized source of n-3 polyunsaturated fatty acids (PUFAs) for humanconsumption with high phospholipid (PL) content. Studies have shown that PL may improve bioavailability of n-3PUFAs. Arctic Nutrition’s herring roe product MOPL™30 is a PL: docosahexaenoic acid (DHA)-rich fish oil mixture,with a DHA:eicosapentaenoic acid (EPA) ratio of about 3:1, which is also rich in choline. In this pilot study, we determinedif MOPL30 could favorably affect plasma lipid parameters and glucose tolerance in healthy young adults.Methods: Twenty female and one male adults, between 22 and 26 years of age, participated in the study. Participantstook encapsulated MOPL30, 2.4 g/d EPA + DHA, for 14 days, and completed a three-day weighed food record beforeand during the capsule intake. Plasma lipids and their fatty acid (FA) composition, plasma and red blood cell (RBC)phosphatidylcholine (PC) FA composition, acylcarnitines, choline, betaine and insulin were measured before and aftersupplementation (n = 21), and one and four weeks after discontinuation of supplementation (n = 14). An oral glucosetolerance test was performed before and after supplementation.Results: Fasting plasma triacylglycerol and non-esterified fatty acids decreased and HDL-cholesterol increased after 14 daysof MOPL30 intake (p < 0.05). The dietary records showed that PUFA intake prior to and during capsule intake was notdifferent. Fasting plasma glucose was unchanged from before to after supplementation. However, during oral glucosetolerance testing, blood glucose at both 10 and 120 min was significantly lower after supplementation with MOPL30compared to baseline measurements. Plasma free choline and betaine were increased, and the n-6/n-3 polyunsaturated(PUFA) ratio in plasma and RBC PC were decreased post-supplementation. Four weeks after discontinuation of MOPL30,most parameters had returned to baseline, but a delayed effect was observed on n-6 PUFAs.Conclusions: Herring roe rich in PL improved the plasma lipid profile and glycemic control in young adults with anoverall healthy lifestyle.Keywords: Herring roe, Phospholipids, Eicosapentaenoic acid, Docosahexaenoic acid, Omega-3 polyunsaturated fattyacids, Glycemic control, Choline, AcylcarnitinesBackgroundThe health benefits of a higher fish intake, thereby increas-ing the intake of n-3 long-chain polyunsaturated fatty acids(PUFAs) and reducing the n-6 PUFA/n-3 PUFA ratio, hasbeen documented in several studies [1]. Cardioprotectiveeffects of n-3 PUFAs, in particular eicosapentaenoic acid(EPA) and docosahexaenoic acid (DHA), have been attrib-uted to reduction in fasting triacylglycerol (TAG), bloodpressure lowering, anti-inflammatory and antiarrhythmiceffects, improved insulin sensitivity and vascular endothelialfunction, and reduced thrombotic tendency [2]. The effi-cacy of n-3 PUFAs in the prevention of heart disease hasbeen challenged in recent meta-studies, but it is importantto note that newer studies could be hampered by a highergeneral intake of n-3 PUFAs and improved treatment pro-tocols for heart patients [3]. The current recommended* Correspondence: bodil.bjorndal@k2.uib.no1Department of Clinical Science, University of Bergen, Bergen N-5020,NorwayFull list of author information is available at the end of the article© 2014 Bjørndal et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the CreativeCommons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, andreproduction in any medium, provided the original work is properly credited. The Creative Commons Public DomainDedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,unless otherwise stated.Bjørndal et al. Lipids in Health and Disease 2014, 13:82http://www.lipidworld.com/content/13/1/82intake is 250 mg/day EPA + DHA for the general popula-tion, and 300 mg/day for pregnant women (European FoodSafety Authority (EFSA)). The American Heart Association(AHA) recommends 1 g/day EPA + DHA for patients withcardiovascular disease (CVD). Combined with the increasedfocus on n-3 PUFA intake in the media, this has led to alarge n-3 PUFA supplement market dominated by fish oilfrom sardines. However, the need for new sources of high-quality EPA and DHA is increasing.Immature roe from spring-spawning Norwegian herringis an underutilized source of n-3 PUFA-rich phospholipids(PLs). Of the approximately 600,000-ton herring caught inNorway each year, only a small percentage of herring roeis used for human consumption. The product MOPL30(Arctic Nutrition) from herring roe contains about 45% n-3 PUFA (mg/g product basis), with a DHA:EPA ratio ofapproximately 3:1. In addition, 30% of the lipids are PL ofwhich most (75%) in the form of phosphatidylcholine(PC). Thus herring roe provides choline, an important nu-trient involved in many biochemical pathways.The bioactivity of n-3 PUFAs may be influenced by thelipid structures in which they are incorporated. PLs andfree fatty acids have increased bioavailability compared toTAG and ethyl ester forms of n-3 PUFAs, respectively[4,5]. PL from krill have been shown to influence gene ex-pression more than TAG from fish oil in mice, at a similardose of EPA and DHA [6]. In particular, genes involved inglucose and lipid metabolism were more affected by PLthan TAG [6,7]. A recent study comparing the bioavail-ability of PL and TAG in the form of krill oil and fish oilin healthy subjects demonstrated increased levels of EPAand DHA in plasma and red blood cells (RBC) after fourweeks of krill oil intake compared to fish oil [8]. Inaddition, animal studies have shown a more efficient re-duction in plasma lipid levels with PL compared to TAGintervention [9]. Herring roe oil supplementation hasshown promising results in animal studies, including re-duction in plasma lipids and inflammatory parameters,and improved insulin sensitivity [10,11].The aim of this study was to determine the effect of n-3PUFA when given in PL-rich herring roe on blood lipidsand glucose tolerance in healthy subjects with a balanceddiet, and to determine uptake of n-3 PUFAs into red bloodcells as a measure of bioavailability. Follow-up sampleswere included to determine how long the n-3 PUFAremained in circulation after discontinuation of supple-mentation (washout effects).ResultsCharacteristics of the study populationThe study included twenty-one young, healthy individualsaged 20 to 26 years, with a mean ± SD body mass index of21.2 ± 2.8, and range between 15.1 and 26.7. Fourteen ofthe participants completed a three day weighed foodrecord during the two weeks prior to supplementation, andagain during the two weeks intervention. The energy %from PUFA in the habitual diet was (mean ± SD) 7.5 ± 2.8before and 6.7 ± 2.0 during the intervention (p = 0.264, n =14), indicating that the dietary intake of PUFA remainedunchanged during the study period. Furthermore, therewas no change in dietary intake of total fat, saturated fattyacids (FA), monounsaturated FA, protein or carbohydrate(data not shown).The capsules were taken during a meal, and there wereno reports of reflux or unpleasant taste following capsuleintake.MOPL30 supplementation affected plasma lipid levelsPlasma lipid levels were measured at baseline (start) andafter (end) two weeks of MOPL30 supplementation. Inaddition, washout (WO) samples were taken one and fourweeks after the final day of capsule intake. The TAG levelwas significantly reduced in the end samples (21% reduc-tion). However, the reduction at WO week one (p = 0.10)and four (p = 0.30) compared to start was not significant(Figure 1a). Non-esterified FAs (NEFAs) were also signifi-cantly reduced after two weeks of MOPL30 intake(23.3%), and remained unchanged, however insignificantly,one (34.3%, p = 0.17) and four weeks (29.8%, p = 0,24) afterdiscontinued supplementation (Figure 1b). Despite a highPL content in the supplement, plasma PL levels were notaltered (Figure 1c).The total cholesterol level in plasma was not changed byMOPL30 intake (Figure 1d). HDL-cholesterol, however,increased by 5.5% at end compared to start (Figure 1e),while LDL-cholesterol was unchanged (Figure 1f). Thisled to a trend towards an increased HDL/LDL-cholesterolafter MOPL30 intake (9.0%; Figure 1g). Surprisingly, whileplasma HDL-cholesterol returned to initial values afterfour weeks of WO, total- and LDL-cholesterol was signifi-cantly reduced at 4 week WO compared to start samples(10.6% reduction in WO week 4 vs. start).Fatty acid composition in plasma and red blood cellsTotal fatty acid composition was measured in plasmabefore and after two weeks of supplement. Total n-3PUFAs in plasma were increased 1.6 fold, mainly due toa 2.2 fold increase in EPA, and a 1.5 fold increase inDHA (Table 1). One week after the end of supplementa-tion, EPA and DHA had decreased by 44% and 24%, re-spectively, compared to the end values. By four weeks ofWO, all plasma n-3 PUFAs had returned to start levels.Concomitant with the increase in EPA and DHA duringthe 2 weeks supplementation, n-6 PUFAs showed a de-crease of 8.2%. Interestingly, n-6 PUFAs, in particulararachidonic acid (AA) did not return to start levelsas quickly as EPA and DHA after discontinuation ofsupplementation.Bjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 2 of 12http://www.lipidworld.com/content/13/1/82Rather AA remained lower than start values in the four-week WO samples. Although mead acid was low in startsamples, as expected with a high habitual PUFA intake, itstill showed a significant decrease with the MOPL30 sup-plement (27.7% reduction). The total fatty acid content inplasma was significantly reduced after two weeks of supple-ment, consistent with the reduced TAG and NEFA. The n-6/n-3 PUFA ratio was within recommendations in the startsamples, consistent with the participants’ balanced intakeof fatty acids (Table 1). The n-6/n-3 ratio was further de-creased by 44.8% post-supplementation, but had returnedto start values at WO week 4.As most of the EPA and DHA in MOPL30 are in theform of PC, the fatty acid composition of PC was mea-sured both in plasma and in red blood cells. The findingsin plasma PC paralleled the findings in total plasma FAs,with a 2.1 fold increase in EPA and a 1.6 increase in DHApost-supplementation, resulting in a 45.2% decrease in then-6/n-3 PUFA ratio (Table 2). At WO week 1, EPA andDHA were reduced by 39.3% and 21.9%, respectively, rela-tive to end values. Incorporation of EPA and DHA intoRBC membranes is believed to better indicate long termstorage than plasma levels [12]. We found a 2.1 foldincrease in EPA and a 1.4 fold increase in DHA post-supplement, similar to results in plasma, resulting in a 1.7fold increase in the RBC PC omega-3 index and a 40.6%reduction in the n-6/n-3 PUFA ratio (Table 3). AA in theplasma PC and RBC PC was not significantly altered byMOPL30, although it was significantly reduced in plasmatotal fatty acids (Tables 1, 2 and 3). The WO effect on theRBC PC EPA was similar to that in the plasma PC afterone week (39% reduction relative to end values), while thedecrease in the RBC PC DHA was lower (11% reductionrelative to end values).Plasma choline increased with MOPL30Both choline and its metabolite betaine increased inplasma after two weeks of MOPL30 supplement (Figure 2).Although the intake of PC was increased during supple-mentation, total plasma- and RBC PCs were reduced post-supplementation, as measured by 31P nuclear magneticresonance (NMR) (Figure 3a and b). However, a higherproportion of EPA and DHA-containing PCs were ob-served in both plasma and RBC (Tables 2 and 3). PlasmaTAG was reduced, while no change was seen in choles-terol esters (Figure 3a). Total cholesterol, measured by 1HNMR, was not influenced by two weeks of supplement(mean ± SD start vs end; 0.95 ± 0.18 mmol/L vs 0.88 ±0.019 mmol/L, p = 0.096). The plasma TAG level mea-sured with NMR was similar to the plasma TAG-levelmeasured by enzymatic-analysis (Figure 1). Sphingomyelin(SPH), PC, and cholesterol were reduced in RBC by twoweeks of MOPL30 treatment (Figure 3b). Interestingly,while cholesterol returned to start levels after four weeksWO, SPH and PC remained lower than start values.HDL cholesterolStartEndWO week 1WO week*TAGStartEndWO week 1WO week***Total cholesterolStartEndWO week 1WO week 40123456mmol/L**NEFAStartEndWO week 1WO week*LDL cholesterolStartEndWO week 1WO week 401234mmol/L**PhospholipidsStartEndWO week 1WO week 401234mmol/LHDL/LDL cholesterolStartEndWO week 1WO week ratio*a b c de f gFigure 1 Plasma lipid levels in response to MOPL30. Levels of triacylglycerol (TAG, a), non-esterified fatty acids (NEFA, b), phospholipids (c),total cholesterol (d), high-density lipoprotein (HDL) cholesterol (e), low-density lipoprotein (LDL) cholesterol (f), and the HDL/LDL cholesterol ratio(g) in fasted plasma samples taken at baseline (start), after 14 days of supplement (end), and one week (wash out (WO) week 1) and four weeks(WO week 4) after discontinuation of supplement. Values are given as means with standard deviations, and significant changes between start andend (n = 21) and start and WO (n = 13) are indicated (*p < 0.05, **p < 0.01, ***p < 0.001).Bjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 3 of 12http://www.lipidworld.com/content/13/1/82Plasma carnitine and acylcarnitine levelsCarnitine is essential in the transport of long-chainfatty acids across the mitochondrial membranes. Highserum levels of long- and medium-chain plasma acyl-carnitines are linked to increased risk of disease pro-gression in patients with cardiac disease, and mayindicate defects in mitochondrial function [13]. In thecurrent study with healthy individuals, carnitine wasinsignificantly reduced (p = 0.054), while its precursorsγ-butyrobetaine and trimethyllysine were reduced byMOPL30 (Figure 4a-c). In addition, all measured plasmaacylcarnitines except the medium-chain octanoylcarni-tine (8-carbon, p = 0.103), were significantly reduced byMOPL30 (Figure 4d-h). The largest reduction (29% com-pared to start) was seen for the short-chain acetylcarnitine(2-carbon). The effect on γ-butyrobetaine, trimethyllysineand all acylcarnitines remained significantly reduced com-pared to start in both the one- and four week WO samples,indicating a possible prolonged effect of the supplement onthese parameters.Oral glucose tolerance testSince previous studies in animals have indicated improvedglucose metabolism after herring roe diets, we investigatedthe effect of two weeks MOPL30 supplement on glucosetolerance in healthy individuals. No change was observedin fasting insulin and glucose before and after the supple-mentation period (Figure 5a and b). However, the bloodglucose level in response to a 75 g oral dose of glucosewas reduced both at 10 and 120 minutes post-ingestionafter the intervention (Figure 5c). Although all participantswere individuals with normal glucose sensitivity accordingto their glucose tolerance test results, the area under thecurve was significantly decreased, suggesting improvedglucose response (Figure 5d).DiscussionThere is an increased demand for new sources of high-quality n-3 PUFAs for human consumption, and PC-richlipids from herring roe is a promising product in this re-gard. Supplementation with DHA- and EPA-rich PC mayTable 1 Plasma fatty acids during the studyμg FA/ml plasma Start End WO 1 week WO 4 weeks∑ FAs 2999 ± 605 2811 ± 449* 2767 ± 409* 2677 ± 443**∑ SFAs 956.4 ± 219.2 881.5 ± 151.1* 875.4 ± 154.8 708.6 ± 207.1**C16:0 651.9 ± 172.0 589.5 ± 121.6** 582.0 ± 119.6 558.2 ± 121.6**∑ MUFAs 708.6 ± 207.1 573.8 ± 124.8*** 613.4 ± 132.7* 583.4 ± 140.5*C16:1n-7 39.8 ± 19.2 30.8 ± 11.6* 34.6 ± 20.3 34.1 ± 17.6C16:1n-9 6.91 ± 2.85 6.10 ± 2.08* 6.63 ± 2.80 6.90 ± 2.75*C18:1n-7 45.2 ± 15.4 36.5 ± 10.6** 36.1 ± 6.6* 36.4 ± 9.3C18:1n-9 568.2 ± 171.9 454.0 ± 101.0*** 491.9 ± 112.1* 463.4 ± 111.1*∑ n-9 PUFAs 3.10 ± 1.29 2.24 ± 0.48** 2.75 ± 1.38 2.55 ± 1.01**C20:3n-9 (MA) 3.10 ± 1.29 2.24 ± 0.48** 2.75 ± 1.38 2.55 ± 1.01**∑ n-6 PUFAs 1123 ± 190 1031 ± 180* 1036 ± 148* 1049 ± 141*C18:2n-6 862.7 ± 147.9 806.2 ± 153.3 814.5 ± 110.1 821.0 ± 93.7C20:2n-6 6.26 ± 2.43 4.91 ± 1.76*** 5.52 ± 1.64 5.90 ± 2.08C18:3n-6 7.75 ± 5.00 4.33 ± 2.41*** 6.96 ± 4.075 7.16 ± 6.84C20:3n-6 40.5 ± 17.3 27.7 ± 9.93*** 33.3 ± 9.78* 35.4 ± 13.9C20:4n-6 (AA) 197.8 ± 51.6 182.3 ± 41.1* 170.3 ± 41.6*** 173.0 ± 50.9*C22:4n-6 4.33 ± 1.58 2.92 ± 0.71*** 3.32 ± 0.92** 3.70 ± 1.56**∑ n-3 PUFAs 200.8 ± 64.1 315.6 ± 62.8*** 232.7 ± 62.9 197.0 ± 74.0C18:3n-3 19.8 ± 8.17 16.6 ± 6.06* 20.0 ± 8.85 19.0 ± 8.0C20:5n-3 (EPA) 49.4 ± 27.1 109.7 ± 37.1*** 61.7 ± 31.7 47.3 ± 32.7C22:5n-3 (DPA) 17.6 ± 5.36 18.4 ± 4.27 18.0 ± 4.22 17.0 ± 5.43C22:6n-3 (DHA) 108.1 ± 30.4 166.1 ± 30.5*** 127.0 ± 29.5** 108.4 ± 35.2∑ n-6:∑ n-3 ratio 6.10 ± 1.81 3.37 ± 0.82*** 4.75 ± 1.42* 5.88 ± 1.72Abbreviations: AA arachidonic acid, DHA docosahexaenoic acid; EPA eicosapentaenoic acid; FA fatty acid; MA mead acid; MUFA unsaturated fatty acids;PUFA polyunsaturated fatty acids; SFA saturated fatty acids; WO, wash out.Data are means ± SD. Significantly different end and start values (n = 21) and WO and start values (n = 13) are indicated (*p < 0.05, **p < 0.01, ***p < 0.001).Bjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 4 of 12http://www.lipidworld.com/content/13/1/82have additional benefits compared to DHA- and EPA-richTAG both due to PL being more easily incorporatedinto cellular membranes, as well as being a source ofthe essential nutrient choline. In this two-week inter-vention in young healthy adults with high habitual fishintakes, there was a rapid increase in EPA and DHA inRBC PC, plasma FA and plasma PC. Furthermore, therewas a corresponding improved lipid status, including adecrease in plasma TAG and NEFA, and increased HDL-cholesterol, choline, and betaine. These findings demon-strate that MOPL30 had significant biological effects inhealthy subjects.The participants were given 2350 mg EPA and DHAdaily, comparable to doses utilized in patients with CVDTable 2 Plasma phosphatidylcholine fatty acids during the studyFatty acids, wt% Start End WO 1 week WO 4 weeksC16:0 27.1 ± 3.11 26.8 ± 3.07 26.6 ± 3.73 27.2 ± 3.54C16:1n-7 0.48 ± 0.14 0.46 ± 0.10 0.48 ± 0.25 0.79 ± 0.82C18:1n-7 1.54 ± 0.20 1.52 ± 0.25 1.50 ± 0.25 1.41 ± 0.24C18:1n-9 10.8 ± 1.66 9.60 ± 1.14** 10.9 ± 1.92 10.6 ± 2.03C20:3n-9 (MA) 0.12 ± 0.04 0.08 ± 0.02*** 0.11 ± 0.06 0.11 ± 0.04*C18:2n-6 23.8 ± 2.73 21.9 ± 2.75* 23.6 ± 2.16 24.2 ± 3.02C20:2n-6 0.53 ± 0.10 0.47 ± 0.07*** 0.50 ± 0.10 0.51 ± 0.10C20:3n-6 2.58 ± 0.78 1.87 ± 0.55*** 2.26 ± 0.54 2.43 ± 0.68C20:4n-6 (AA) 8.07 ± 1.31 7.65 ± 1.34 7.16 ± 1.49* 7.34 ± 1.53C22:4n-6 0.26 ± 0.20 0.17 ± 0.03* 0.18 ± 0.04** 0.20 ± 0.07C18:3n-3 0.25 ± 0.08 0.20 ± 0.06** 0.30 ± 0.15 0.30 ± 0.02C20:5n-3 (EPA) 1.90 ± 1.01 3.97 ± 1.43*** 2.41 ± 1.30 1.84 ± 1.02C22:5n-3 (DPA) 0.77 ± 0.17 0.85 ± 0.20 0.82 ± 0.17 0.76 ± 0.15C22:6n-3 (DHA) 4.20 ± 0.87 6.52 ± 1.10*** 5.09 ± 1.03** 4.25 ± 0.67∑ n-6:∑ n-3 ratio 5.29 ± 1.41 2.90 ± 0.68*** 4.15 ± 1.13 5.12 ± 1.23Abbreviations: AA arachidonic acid, DHA docosahexaenoic acid; EPA eicosapentaenoic acid; FA fatty acid; MA mead acid; MUFA unsaturated fatty acids;PUFA polyunsaturated fatty acids; SFA saturated fatty acids; WO wash out.Data are means ± SD. Significantly different end and start values (n = 21) and WO and start values (n = 13) are indicated (*p < 0.05, **p < 0.01, ***p < 0.001).Table 3 Red blood cell phosphatidylcholine fatty acids during the studyFatty acids, wt% Start End WO 1 week WO 4 weeksC16:0 32.2 ± 3.62 31.3 ± 3.43 31.6 ± 3.46 31.6 ± 3.87C16:1n-7 0.33 ± 0.15 0.24 ± 0.05** 0.30 ± 0.14 0.29 ± 0.12C18:1n-7 1.65 ± 0.19 1.67 ± 0.18 1.60 ± 0.17 1.62 ± 0.15C18:1n-9 16.2 ± 1.53 15.8 ± 0.98* 16.1 ± 1.00 15.8 ± 1.20C20:3n-9 (MA) 0.06 ± 0.02 0.05 ± 0.02 0.05 ± 0.02* 0.05 ± 0.02C18:2n-6 20.0 ± 1.65 18.8 ± 1.80*** 20.2 ± 1.55 20.96 ± 1.83C20:2n-6 0.32 ± 0.10 0.34 ± 0.06 0.32 ± 0.05 0.34 ± 0.07C20:3n-6 1.65 ± 0.06 1.34 ± 0.38*** 1.35 ± 0.32*** 1.49 ± 0.39C20:4n-6 (AA) 5.33 ± 0.90 5.18 ± 0.86 4.97 ± 0.91* 4.48 ± 1.48C22:4n-6 0.22 ± 0.09 0.22 ± 0.06 0.23 ± 0.04 0.21 ± 0.07C18:3n-3 0.18 ± 0.07 0.23 ± 0.28 0.18 ± 0.07 0.17 ± 0.05C20:5n-3 (EPA) 1.10 ± 0.47 2.35 ± 0.85*** 1.43 ± 0.57 1.08 ± 0.54C22:5n-3 0.53 ± 0.10 0.56 ± 0.13 0.56 ± 0.11 0.55 ± 0.11C22:6n-3 (DHA) 2.43 ± 0.52 3.48 ± 0.60*** 3.10 ± 0.63** 2.58 ± 0.52∑ n-6:∑ n-3 ratio 6.85 ± 1.64 4.07 ± 0.80*** 5.37 ± 1.12** 6.58 ± 1.40Omega-3 index 3.53 ± 0.88 5.83 ± 1.26*** 4.52 ± 0.94* 3.65 ± 0.84Abbreviations: AA arachidonic acid, DHA docosahexaenoic acid; EPA eicosapentaenoic acid; FA fatty acid; MA mead acid; MUFA unsaturated fatty acids;PUFA polyunsaturated fatty acids; SFA saturated fatty acids; WO wash out.Data are means ± SD. Significantly different end and start values (n = 21) and WO and start values (n = 13) are indicated (*p < 0.05, **p < 0.01, ***p < 0.001).Bjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 5 of 12http://www.lipidworld.com/content/13/1/82or metabolic syndrome to achieve a TAG-lowering effect.In line with this, plasma TAG was reduced and HDL-cholesterol increased after only two weeks of treatment.This indicates a high bioavailability of MOPL30 and a sub-sequent rapid effect on lipid metabolism. It has been shownthat the preferred lipid form for transport of DHA to RBCis lyso-PC, which is rapidly converted to PC [14,15]. Thiscould mean that DHA-rich PC may be preferred for uptakein RBC and putatively in brain. Incorporation of EPA fromfish oil into RBC membranes has been shown to reach asteady state after 180 days [12]. Notably, we observed an in-crease in EPA and DHA in RBC PC similar to that ofplasma after only 14 days. In mice, we recently showed thatsimilar amounts of EPA and DHA in liver PL were achievedwith krill oil and a two-fold higher dose of EPA and DHAfrom fish oil, indicating higher bioavailability of EPA andDHA from the PL-source krill oil [16]. Importantly, in arecent study in which subjects were supplemented with600 mg EPA and DHA from either fish- or krill oil, theomega-3 index was significantly higher in subjects receivingkrill oil than in those given fish oil [8]. However, no effecton plasma TAG was observed at 600 mg/day EPA + DHA.A recent study in adults with high TAG levels showed thata dose of 0.5-2 g/day krill oil for 12 weeks significantly re-duced TAG [17].Although the intake of DHA exceeded that of EPA by2.8 fold, the increase in EPA was higher than DHA in thePC-fraction of both plasma and red blood cells after twoweeks of MOPL30. Studies have shown that the DHAlevel in lipid pools has a less steep dose–response curvethan EPA, which is easy to influence by supplementation[18], and our results confirm this. This can partly be dueto more efficient liberation of DHA from chylomicrons[19], leaving more EPA in chylomicron remnants andCholineμMStartEndWO week 1WO week 40246810 ***BetaineμMStartEndWO week 1WO week 4010203040***a bFigure 2 Plasma choline and betaine levels in response to MOPL30. Levels of choline (a) and betaine (b) in fasted plasma samples taken atbaseline (start), after 14 days of supplement (end), and one week (wash out (WO) week 1) and four weeks (WO week 4) after discontinuation ofsupplement. Values are given as means with standard deviations, and significant changes between start and end (n = 21) and start and WO(n = 13) are indicated (*p < 0.05, **p < 0.01, ***p < 0.001).Plasma lipid classesSPHTAG PE LPC PC CE0. w/wStartEnd*****RBC lipid classes% w/wSPH PC Chol. week 1WO week 4**************a bFigure 3 Lipid classes in plasma and red blood cells (RBC) in response to MOPL30. Comparison of the lipid classes sphingomyelin (SPH),triacylglycerol (TAG), phosphatidyl ethanolamine (PE), lysophosphatidylethanolamine (LPC), phosphatidyl choline (PC), and cholesterol esters (CE)at baseline (start) and after 14 days of supplement (end) in fasting plasma samples (a). Comparison of the lipid classes SPH, TAG, and cholesterol(Chol.) at start, end, and one week (wash out (WO) week 1) and four weeks (WO week 4) after discontinuation of supplement in RBC (b). Analysiswas done by 31P NMR. Values are given as means (%w/w = g/100 g plasma) with standard deviations, and significant changes between start andend (n = 21) and start and WO (n = 13) are indicated (*p < 0.05, **p < 0.01).Bjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 6 of 12http://www.lipidworld.com/content/13/1/82hereby making more EPA available for PL synthesis in liver.In addition, retro-conversion of DHA to EPA is dependenton peroxisomal β-oxidation, and is reported to be at ap-proximately 10% in humans [20,21]. Hansen et al. showedthat 4 g supplement of pure EPA for 5 weeks led to a 6.2fold increase in EPA in plasma phospholipids, and nochange in DHA [18]. In contrast, the same interventionusing a pure DHA supplement led to a 1.9 fold increase inDHA and a 1.7 fold increase in EPA. This demonstrates theimportance of supplementation with DHA and not onlyEPA. Despite a dose of 132 mg DPA/day, and the possibilityof formation of DPA from EPA, DPA levels were not influ-enced by two weeks of MOPL30. In line with this, a de-crease in DPA after uptake of EPA or DHA has beenreported in long-term studies [22,23].Indications of differential effects of n-3 PUFA in PLand TAG form have also been found at the gene level inseveral animal studies [6,7], including genes involved inglucose metabolism. A recent study reported that EPAand DHA supplements may improve insulin sensitivityCarnitineμ MStartEndWO week 1WO week 40102030AcetylcarnitineStartEndWO week 1WO week 4051015μ M*******OctanoylcarnitineStartEndWO week 1WO weekμ M*-ButyrobetaineStartEndWO week 1WO weekμ M*****PropionylcarnitineStartEndWO week 1WO weekμ M*****PalmitoylcarnitineStartEndWO week 1WO weekμ M**TrimethyllysineStartEndWO week 1WO weekμ M****Valerylcarnitineμ MStartEndWO week 1WO week*****a b cd e fg hFigure 4 Plasma carnitine and acylcarnitines in response to MOPL30. Levels of carnitine (a) and the carnitine precursors gamma-butyrobetaine(b), trimethylysine (c), even-chain acylcarnitines propionylcarnitine (d), and isovaleryl/valerylcarnitine (e), and odd-chain acylcarnitines acetylcarnitine(f), octanoylcarnitine (g), and palmitoylcarnitine (h) in fasted plasma samples taken at baseline (start), after 14 days of supplement (end), and one week(wash out (WO) week 1) and four weeks (WO week 4) after discontinuation of supplement. Number of carbons in the acyl-chains are indicated byC2-16. Values are given as means with standard deviations, and significant changes between start and end (n = 21) and start and WO (n = 13) areindicated (*p < 0.05, **p < 0.01, ***p < 0.001).Bjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 7 of 12http://www.lipidworld.com/content/13/1/82in young obese individuals [24]. While some meta-studieshave failed to show an effect between n-3 PUFA intake andincident type 2 diabetes mellitus (T2DM) [25,26], others in-dicate a reduced risk of T2DM with increased intake ofPUFAs [27,28]. Based on findings in humans and from re-cent animal studies, PL supplements could be expected tohave potent effects on glucose metabolism. The small, butsignificant, improvement in glucose response in healthy in-dividuals after only two weeks of intervention suggests apotential for the use of MOPL30 in insulin resistant indi-viduals, or patients with diabetes.The conditionally essential nutrient choline is a quater-nary amine, and is mainly utilized for the synthesis of PCand sphingomyelin, as well as lysophosphatidylcholine. Inaddition, choline can be oxidized to betaine, which is in-volved in the remethylation of homocysteine to methio-nine in the one-carbon cycle [29]. Finally, in the neuronscholine is a precursor for the important neurotransmittorand vasodilator acetylcholine [30-32], and increased intakehas been connected with improved cognition, learningand memory [33-35]. Betaine holds an important role inthe liver, and has a potential therapeutic use in thetreatment of fatty liver disease as well as homocysteine-mia, a risk factor for CVD [36,37]. In addition, somestudies have demonstrated that betaine supplementsimprove muscle performance [38]. PC biosynthesis isrequired for VLDL production, both through the CDP-choline (Kennedy) pathway and the phosphatidyletha-nolamine N-methyltransferase (PEMT) pathway. In general,a balanced diet will provide sufficient amounts of choline,but groups which may benefit from choline supplementa-tion are pregnant and lactating women, infants, and cirrho-sis patients [39]. Thus, a PC supplement can both reducethe need for methyl-donors for PC synthesis, and supplybetaine for homocysteine remethylation, which will bebeneficial in situations where methyl donors are limited[40]. Interestingly, while MOPL30 supplementation led toincreased EPA and DHA-rich PC in plasma and RBC, thetotal level of PC decreased, with a concomitant increase inplasma free choline. This may indicate a higher level ofPC degradation as a result of increased dietary intake, en-suring maintenance of the strictly regulated choline bal-ance in the human body [41]. We were unable to measureacetylcholine in plasma due to its short half-life, however,Fasting glucosemmol/LStartEndWO week 1WO week 40246Oral glucose tolerance test0 30 60 90 120 1500246810Time (min)mmol/LStartEnd* *Fasting insulinmIU/LStartEndWO week 1WO week 40246810Area under the curve (AUC)StartEnd5006007008009001000min*mmol/L *a bc dFigure 5 Fasting glucose and insulin levels, and oral glucose tolerance. Levels of glucose (a), insulin (b), in fasted plasma and serumsamples, respectively, taken at baseline (start), after 14 days of supplement (end), and one week (wash out (WO) week 1) and four weeks(WO week 4) after discontinuation of supplement. Significant changes between start and end (n = 21) and start and WO (n = 13) are indicated byP-values. Oral glucose toleranse was measured at start and end of the experiment, blood glucose levels at baseline, 10, 30, 60, and 120 minutesafter glucose ingestion are given (c). The area under the curve was calculated at start and end (d). All values are given as means with standarddeviations, and significant changes between start and end (n = 21) are indicated by *p < 0.05.Bjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 8 of 12http://www.lipidworld.com/content/13/1/82both the one-carbon cycle/remethylation process and theproduction of acetylcholine may potentially have beenstimulated by increased choline levels. DHA has beendemonstrated to increase synaptic transmission in mam-malian brain cells, and this effect was potentiated by phos-phatidylcholine [42]. Thus, MOPL30 may have beneficialeffects on cognitive function. It would be valuable tomeasure plasma choline acetyltransferase activity in futureclinical trials to verify if acetylcholine production is stimu-lated by MOPL30 in humans.As high plasma levels of long- and medium-chainacylcarnitines are linked to increased heart failure inCVD patients, they have been put forward as potentialbiomarkers of cardiovascular risk [13]. Incomplete β-oxidation, impaired substrate switching, and dysregula-tion of mitochondria during insulin resistance can causeelevated levels of intermediate oxidation products, andthis can be reflected in plasma acylcarnitine levels [43,44].Thus, it is of interest to establish whether dietary interven-tion with n-3 PUFAs affect these plasma parameters inhealthy adults, as EPA and DHA are known to stimulatemitochondrial β-oxidation. We observed a reduction in allacylcarnitines after a two-week intervention with MOPL30,including the risk-associated palmitoylcarnitine.In further studies it will be interesting to determine if thesupplement can benefit patients with insulin resistance,both with regard to plasmaTAG levels, mitochondrial func-tion, and glucose tolerance. It will be of particular interestto compare the bioactivity of MOPL30 and TAG EPA andDHA supplements at lower doses of EPA and DHA. Ina follow-up study, a double blind comparison to fish oilwill be performed to identify possible PL-specific effects ofMOPL30. Also, a rodent study is planned to examinebioaccretion of EPA and DHA into brain and other tissues.ConclusionsEPA and DHA-rich PC from herring roe was taken up byRBC during the two week intervention. Several parametersin blood were affected, including a reduction in TAG andNEFA, and an increase in HDL cholesterol, choline, andbetaine. Further, there was improved glucose toleranceamong the participants after two weeks. Based on thefindings from this short-term pilot study with 2.4 g EPA +DHA per day, MOPL30 may provide significant effects onlipid status and glucose tolerance.MethodsStudy subjectsThis intervention study was performed at the Universityof Bergen according to Good Clinical Practice Guidelinesand the World Medical Association Declaration ofHelsinki. The Regional Ethics Committee, REK vest, ap-proved the protocol (REK vest, approval no. 2013/112),and informed consent was obtained from all the subjects.Healthy young adults (21 women and one man) aged21 to 26 years were recruited on a voluntary basis. Ofthe 27 adults asked, six were not included in the studydue to unwillingness to take capsules and/or blood sam-ples. Exclusion criteria were conditions requiring medica-tion, pregnancy and diabetes type I or II. The participantswere instructed not to make any major changes to theirdiet three weeks before, during, or four weeks after inter-vention, with the exception of avoiding using fish eggproducts like caviar. Participants were instructed to per-form a three-day weighed food record within the twoweeks before, as well as during the intervention. Resultswere analyzed by the program “Mat på Data” (http://www.matportalen.no/verktoy/mat_pa_data/), and mean dietaryintake of nutrients of interest were calculated as percent-age of total energy intake (energy %).Supplement and study designMOPL30 is a capsulated herring roe PL supplement,where each capsule contains 511 mg total lipid, of which30% are PL, with 56 mg EPA, 158 mg DHA, and 12 mg n-3 DPA. The participants received 11 capsules per day for14 days, corresponding to a daily dose of 1738 mg DHAand 616 mg EPA. Four capsules were taken at breakfastand lunch and three capsules were taken at dinnertime.The last day of capsule intake (end), blood samples weredrawn the next morning between 8 and 11 am after anovernight fast, an oral glucose tolerance test was per-formed (see description below), and capsules were dividedbetween the remaining meals of the day. Blood sampleswere drawn the next morning after taking the last capsulebetween 8 and 11 am after an overnight fast, followed byan oral glucose tolerance test. Of the 21 participants, 14were recruited for additional fasting blood samples oneweek (WO week one) and four weeks (WO week four)after the final day of supplement. One participant was ex-cluded due to lack of fasting at WO week four. All bloodsamples were centrifuged and EDTA-plasma and serumwas separated after a minimum of 15 minutes and max-imum of 30 minutes at room temperature. Blood samplesfor isolation of RBC were drawn in EDTA tubes, centri-fuged at 3000 rpm for 10 minutes, and plasma and inter-face removed. RBC were subsequently washed three timesin PBS, with centrifugation and removal of buffy coat be-tween each wash. All samples were aliquoted and storedat −80°C for further analysis.Oral glucose tolerance testAfter an overnight fast, blood was drawn for measurementof fasting glucose and insulin as described above. Inaddition, a rapid analysis of blood glucose was performedusing a FreeStyle Lite (Abbott Diabetes Care, Inc., Alameda,CA, USA). Glucose dissolved in water was ingested in nomore than 5 minutes (300 ml 0.25 g/ml glucose with 5%Bjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 9 of 12http://www.lipidworld.com/content/13/1/82lemon juice), and blood glucose was measured by FreeStyleLite at 10, 30, 60 and 120 minutes after glucose ingestion.The area under the curve was calculated by Prism Graph-Pad Software (San Diego, CA, USA).Enzymatic analysis of blood parametersLipids were measured enzymatically in EDTA plasma on aHitachi 917 system (Roche Diagnostics GmbH, Mannheim,Germany) using the triacylglycerol (GPO-PAP), cholesterol(CHOD-PAP), HDL-cholesterol plus and LDL-cholesterolplus kit from Roche Diagnostics, and the non-esterifiedfatty acid (NEFA FS) kit and the Phospholipids FS kit fromDiaSys Diagnostic Systems GmbH (Holzheim, Germany).Glucose was measured in EDTA-plasma using the Gluco-quant Glucose/HK (GLU) kit from Roche Diagnostics. In-sulin was measured using routine methods at the centrallaboratory at Haukeland University Hospital.Analysis of plasma total fatty acid composition, andplasma and RBC PC fatty acid compositionThe total fatty acid composition in EDTA-plasma was an-alyzed as previously described [45]. For analysis of theplasma PC fatty acids, plasma total lipids were extractedbased on Folch, then PC was separated from other lipidsby HPLC using YMC diol-120-NP column, 250 mm×4.6 mm ID, using hexane/acetone/methanol/chloroform(1/1/6/4) as the eluting solvent system. The column efflu-ent was spilt to an evaporative light scattering detector forquantitation and to fraction collector for recovery. Fattyacids in the PC fraction were converted to their respectivemethyl esters then separated and quantified by capillarycolumn GLC [46].Analysis of plasma and RBC lipid composition by 1Hor 31P NMRLipids were extracted from 0.5 ml serum by Folch Solvent(1 ml each of CDCl3 MeOD and CsEDTA (0.2 M), pH 8).After centrifugation, the lower layer was analyzed at600 MHz cQNP using a NMR spectrometer Avance III600 (Bruker, Karlsruhe, D), magnetic flux density 14.1Tesla, a QNP cryo probe, and automated sample changerBruker B-ACS 120. Computer Intel Core2 Duo 2.4 GHzunder MS Windows XP and Bruker TopSpin 2.1 was usedfor acquisition, while Bruker TopSpin 2.1 was used forprocessing [47-50].Plasma choline, betaine, carnitine and acylcarnitinesPlasma choline, betaine, free carnitine and its precur-sors: trimethyllysine and γ-butyrobetaine, as well as short-,medium-, and long-chain acylcarnitines, were analysed inplasma using LC/MS/MS as described previously [10].Stable isotope dilution LC/MS/MS was used for quantifi-cation of choline and betaine. Choline and betaine weremonitored in positive MRM MS mode using characteristicprecursor-product ion transitions: m/z 76→ 58, m/z104→ 60 and m/z 118→ 58, respectively. The internalstandards, choline-trimethyl-d9 (d9-choline) and d11-betaine, were added to plasma samples before protein pre-cipitation, and were similarly monitored in MRM mode atm/z 85→ 66, m/z 113→ 69 and m/z 129→ 66, respect-ively. Various concentrations of choline and betaine stan-dards and a fixed amount of internal standards were spikedinto 4% albumin (BSA) to prepare the calibration curves forquantification of plasma analytes.Statistical analysisData was analyzed using Prism Software (Graph-Pad Soft-ware). The results are shown as means with standard devi-ation (SD). D’Agostino & Pearson omnibus normality testwas used to determine normal distribution. Paired t-test orWilcoxon matched-pairs signed ranked test, for parametricdata and non-parametric data, respectively, were per-formed to evaluate statistical differences between start andend samples, between end and WO week one, and betweenend and WO week four samples. P-values < 0.05 were con-sidered significant.Competing interestsThis work was partly supported by Arctic Nutrition AS, and at the time of thestudy, AB was an employee of Arctic Nutrition.Authors’ contributionsBB, ES, JG, AB, and RKB planned and designed the study. BB, ES and JGperformed the study. PB performed the total plasma fatty acid compositionassay. AS, BWKD, and SMI were responsible for the acylcarnitine analysis,NMR plasma lipid composition analysis, and the phosphatidyl choline fattyacid composition analysis, respectively. BB and AB performed statisticalanalysis, analysed the data, and BB wrote the manuscript. All authors criticallyrevised the manuscript, and read and approved the final manuscript.AcknowledgementsWe would like to thank Kari Williams, Liv Kristine Øysæd, Randi Sandvik, andRoger A. Dyer for excellent technical assistance. The University of Bergenthrough the Clinical Nutrition Program, and the company Arctic Nutrition ASsupported this work.Author details1Department of Clinical Science, University of Bergen, Bergen N-5020,Norway. 2Hormonlaboratoriet, Haukeland University Hospital, Bergen N-5021,Norway. 3Department of Paediatrics, University of British Columbia,Vancouver, BC V5Z4H4, Canada. 4Spectral Service AG, Köln D-50996,Germany. 5Arctic Nutrition AS, Ørsta N-6155, Norway. 6Department of FoodScience & Nutrition, University of Minnesota, St. Paul, MN 55108-1038, USA.7Department of Heart Disease, Haukeland University Hospital, Bergen N-5021,Norway.Received: 13 March 2014 Accepted: 10 May 2014Published: 17 May 2014References1. Mozaffarian D, Rimm EB: Fish intake, contaminants, and human health:evaluating the risks and the benefits. JAMA 2006, 296:1885–1899.2. Harris WS, Dayspring TD, Moran TJ: Omega-3 fatty acids andcardiovascular disease: new developments and applications.Postgrad Med 2013, 125:100–113.3. Harris WS: Are n-3 fatty acids still cardioprotective? Curr Opin Clin NutrMetab Care 2013, 16:141–149.Bjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 10 of 12http://www.lipidworld.com/content/13/1/824. Burri L, Hoem N, Banni S, Berge K: Marine omega-3 phospholipids: metab-olism and biological activities. Int J Mol Sci 2012, 13:15401–15419.5. Davidson MH, Johnson J, Rooney MW, Kyle ML, Kling DF: A novel omega-3free fatty acid formulation has dramatically improved bioavailability dur-ing a low-fat diet compared with omega-3-acid ethyl esters: the ECLIPSE(Epanova((R)) compared to Lovaza((R)) in a pharmacokinetic single-doseevaluation) study. J Clin Lipidol 2012, 6:573–584.6. Burri L, Berge K, Wibrand K, Berge RK, Barger JL: Differential effects of krilloil and fish oil on the hepatic transcriptome in mice.Frontiers Nutrigenomics 2011, 2:1–8.7. Vigerust NF, Bjorndal B, Bohov P, Brattelid T, Svardal A, Berge RK: Krill oilversus fish oil in modulation of inflammation and lipid metabolism inmice transgenic for TNF-alpha. Eur J Nutr 2012, 52:1315–1325.8. Ramprasath VR, Eyal I, Zchut S, Jones PJ: Enhanced increase of omega-3index in healthy individuals with response to 4-week n-3 fatty acid sup-plementation from krill oil versus fish oil. Lipids Health Dis 2013, 12:178.9. Ferramosca A, Conte L, Zara V: A krill oil supplemented diet reduces theactivities of the mitochondrial tricarboxylate carrier and of the cytosoliclipogenic enzymes in rats. J Anim Physiol Anim Nutr (Berl) 2012, 96:295–306.10. Bjorndal B, Burri L, Wergedahl H, Svardal A, Bohov P, Berge RK: Dietarysupplementation of herring roe and milt enhances hepatic fatty acidcatabolism in female mice transgenic for hTNFalpha. Eur J Nutr 2011,51:741–753.11. Higuchi T, Shirai N, Suzuki H: Effects of dietary herring roe lipids onplasma lipid, glucose, insulin, and adiponectin concentrations in mice.J Agric Food Chem 2006, 54:3750–3755.12. Katan MB, Deslypere JP, van Birgelen AP, Penders M, Zegwaard M: Kineticsof the incorporation of dietary fatty acids into serum cholesteryl esters,erythrocyte membranes, and adipose tissue: an 18-month controlledstudy. J Lipid Res 1997, 38:2012–2022.13. Ueland T, Svardal A, Oie E, Askevold ET, Nymoen SH, Bjorndal B, Dahl CP,Gullestad L, Berge RK, Aukrust P: Disturbed carnitine regulation in chronicheart failure - increased plasma levels of palmitoyl-carnitine areassociated with poor prognosis. Int J Cardiol 2012, 167:1892–1899.14. Lemaitre-Delaunay D, Pachiaudi C, Laville M, Pousin J, Armstrong M,Lagarde M: Blood compartmental metabolism of docosahexaenoic acid(DHA) in humans after ingestion of a single dose of [(13)C]DHA inphosphatidylcholine. J Lipid Res 1999, 40:1867–1874.15. Brossard N, Croset M, Normand S, Pousin J, Lecerf J, Laville M, Tayot JL,Lagarde M: Human plasma albumin transports [13C]docosahexaenoicacid in two lipid forms to blood cells. J Lipid Res 1997, 38:1571–1582.16. Tillander V, Bjørndal B, Burri L, Bohov P, Skorve J, Berge RK, Alexson SEH:Fish oil and krill oil supplementations differentially regulate lipidcatabolic and synthetic pathways in mice. Nutr Metab 2014,11. doi:10.1186/1743-7075-11-20.17. Berge K, Musa-Veloso K, Harwood M, Hoem N, Burri L: Krill oil supplemen-tation lowers serum triglycerides without increasing low-density lipopro-tein cholesterol in adults with borderline high or high triglyceride levels.Nutr Res 2014, 34:126–133.18. Hansen J-B, Grimsgaard S, Nilsen H, Nordøy A, Bønaa KH: Effects of highlypurified eicosapentaenoic acid and docosahexaenoic acid on fatty acidabsorption, incorporation into serum phospholipids and postprandialtriglyceridemia. Lipids 1998, 33:131–138.19. Ekström B, Nilson A, Åkesson B: Lipolysis of polyenoic fatty acid esters ofhuman chylomicrons by lipoprotein lipase. Eur J Clin Invest 1989, 19:259–264.20. Conquer JA, Holub BJ: Supplementation with an algae source ofdocosahexaenoic acid increases (n-3) fatty acid status and altersselected risk factors for heart disease in vegetarian subjects. J Nutr 1996,126:3032–3039.21. Conquer JA, Holub BJ: Dietary docosahexaenoic acid as a source ofeicosapentaenoic acid in vegetarians and omnivores. Lipids 1997, 32:341–345.22. Vidgren HM, Ågren JJ, Schwab U, Rissanen T, Hânninen O, Uusitupa MIJ:Incorporation of n-3 fatty acids into plasma lipid fractions, and erythro-cyte membranes and platelets during dietary supplementation with fish,fish oil, and docosahexaenoic acid-rich oil among healthy young men.Lipids 1997, 32:697–705.23. Von Schacky C, Fischer J, Weber PC: Long- term effects of dietary marineomega-3 fatty acids upon plasma and cellular lipids, platelet function,and eicosanoid formation in humans. J Clin Invest 1985, 76:1626–1631.24. Dangardt F, Chen Y, Gronowitz E, Dahlgren J, Friberg P, Strandvik B: Highphysiological omega-3 fatty acid supplementation affects muscle fattyacid composition and glucose and insulin homeostasis in obeseadolescents. J Nutr Metab 2012, 2012:395757.25. Hartweg J, Perera R, Montori V, Dinneen S, Neil HA, Farmer A: Omega-3polyunsaturated fatty acids (PUFA) for type 2 diabetes mellitus.Cochrane Database Syst Rev 2008, 1:CD003205.26. Wu JH, Micha R, Imamura F, Pan A, Biggs ML, Ajaz O, Djousse L, Hu FB,Mozaffarian D: Omega-3 fatty acids and incident type 2 diabetes: asystematic review and meta-analysis. Br J Nutr 2012, 107(Suppl 2):S214–S227.27. Zhang M, Picard-Deland E, Marette A: Fish and marine omega-3 polyunsa-tured fatty acid consumption and incidence of type 2 diabetes: a sys-tematic review and meta-analysis. Int J Endocrinol 2013, 2013:501015.28. Zheng JS, Huang T, Yang J, Fu YQ, Li D: Marine N-3 polyunsaturated fattyacids are inversely associated with risk of type 2 diabetes in Asians: asystematic review and meta-analysis. PLoS One 2012, 7:e44525.29. Ueland PM, Holm PI, Hustad S: Betaine: a key modulator of one-carbon me-tabolism and homocysteine status. Clin Chem Lab Med 2005, 43:1069–1075.30. Amenta F, Tayebati SK: Pathways of acetylcholine synthesis, transport andrelease as targets for treatment of adult-onset cognitive dysfunction.Curr Med Chem 2008, 15:488–498.31. Wessler I, Kilbinger H, Bittinger F, Kirkpatrick CJ: The biological role of non-neuronal acetylcholine in plants and humans. Jpn J Pharmacol 2001, 85:2–10.32. Wessler I, Kirkpatrick CJ, Racke K: Non-neuronal acetylcholine, a locallyacting molecule, widely distributed in biological systems: expression andfunction in humans. Pharmacol Ther 1998, 77:59–79.33. Yang Y, Liu Z, Cermak JM, Tandon P, Sarkisian MR, Stafstrom CE, Neill JC,Blusztajn JK, Holmes GL: Protective effects of prenatal cholinesupplementation on seizure-induced memory impairment. J Neurosci2000, 20:RC109.34. Garner SC, Mar MH, Zeisel SH: Choline distribution and metabolism inpregnant rats and fetuses are influenced by the choline content of thematernal diet. J Nutr 1995, 125:2851–2858.35. Cermak JM, Blusztajn JK, Meck WH, Williams CL, Fitzgerald CM, Rosene DL, Loy R:Prenatal availability of choline alters the development ofacetylcholinesterase in the rat hippocampus. Dev Neurosci 1999, 21:94–104.36. Wang LJ, Zhang HW, Zhou JY, Liu Y, Yang Y, Chen XL, Zhu CH, Zheng RD,Ling WH, Zhu HL: Betaine attenuates hepatic steatosis by reducingmethylation of the MTTP promoter and elevating genomic methylationin mice fed a high-fat diet. J Nutr Biochem 2013, 25:329–336.37. Kempson SA, Vovor-Dassu K, Day C: Betaine transport in kidney and liver:use of betaine in liver injury. Cell Physiol Biochem 2013, 32:32–40.38. Trepanowski JF, Farney TM, McCarthy CG, Schilling BK, Craig SA, Bloomer RJ:The effects of chronic betaine supplementation on exerciseperformance, skeletal muscle oxygen saturation and associatedbiochemical parameters in resistance trained men. J Strength Cond Res2011, 25:3461–3471.39. Zeisel SH: Choline: an essential nutrient for humans. Nutrition 2000,16:669–671.40. Bertolo RF, McBreairty LE: The nutritional burden of methylation reactions.Curr Opin Clin Nutr Metab Care 2013, 16:102–108.41. Li Z, Vance DE: Phosphatidylcholine and choline homeostasis. J Lipid Res2008, 49:1187–1194.42. Cansev M, Wurtman RJ, Sakamoto T, Ulus IH: Oral administration ofcirculating precursors for membrane phosphatides can promote thesynthesis of new brain synapses. Alzheimers Dement 2008, 4:S153–S168.43. Blaak EE: Metabolic fluxes in skeletal muscle in relation to obesity andinsulin resistance. Best Pract Res Clin Endocrinol Metab 2005, 19:391–403.44. Koves TR, Ussher JR, Noland RC, Slentz D, Mosedale M, Ilkayeva O, Bain J,Stevens R, Dyck JR, Newgard CB, Lopaschuk GD, Muoio DM: Mitochondrialoverload and incomplete fatty acid oxidation contribute to skeletalmuscle insulin resistance. Cell Metab 2008, 7:45–56.45. Strand E, Bjorndal B, Nygard O, Burri L, Berge C, Bohov P, Christensen BJ,Berge K, Wergedahl H, Viste A, Berge RK: Long-term treatment with thepan-PPAR agonist tetradecylthioacetic acid or fish oil is associatedwith increased cardiac content of n-3 fatty acids in rat. Lipids HealthDis 2012, 11:82.46. Innis SM, King DJ: Trans fatty acids in human milk are inverselyassociated with concentrations of essential all-cis n-6 and n-3 fatty acidsand determine trans, but not n-6 and n-3, fatty acids in plasma lipids ofbreast-fed infants. Am J Clin Nutr 1999, 70:383–390.47. Diehl BWK: 31P NMR in study of phosphorous containing lipids.Lipid Technol 2002, 14:62–65.Bjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 11 of 12http://www.lipidworld.com/content/13/1/8248. Diehl BWK: High resolution NMR spectroscopy. Eur J Lipid Sci Technol 2001,103:830–834.49. Diehl BWK:Multinuclear High-Resolution Magnetic Resonance Spectroscopy.In Lipid Analysis in Oils and Fats. Edited by Hamilton RJ. London: BlackieAcademic & Professional; 1997:87–135.50. Formes A, Diehl BWK: Investigation of the silicone structure in breast implantsusing 1H NMR. J Pharm Biomed Anal 2013. doi:10.1016/j.jpba.2013.1009.1005.doi:10.1186/1476-511X-13-82Cite this article as: Bjørndal et al.: Phospholipids from herring roeimprove plasma lipids and glucose tolerance in healthy, young adults.Lipids in Health and Disease 2014 13:82.Submit your next manuscript to BioMed Centraland take full advantage of: • Convenient online submission• Thorough peer review• No space constraints or color figure charges• Immediate publication on acceptance• Inclusion in PubMed, CAS, Scopus and Google Scholar• Research which is freely available for redistributionSubmit your manuscript at www.biomedcentral.com/submitBjørndal et al. Lipids in Health and Disease 2014, 13:82 Page 12 of 12http://www.lipidworld.com/content/13/1/82


Citation Scheme:


Citations by CSL (citeproc-js)

Usage Statistics



Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            async >
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:


Related Items