New data on nutrient composition in large selection of commercially available seafood products and its impact on micronutrient intake

Background: Most foods, including seafood, undergo some sort of processing as an integrated part of the global food industry. The degree of processing depends on the type of product produced. Processed seafood products are an important part of the diet; thus, knowledge of nutrient content in seafood products is of great importance. Objective: The aim of this study was to describe the content of selected nutrients in commercially available and market representative seafood products purchased from 3 different years. Methods: Seafood products from 2015 (n = 16), 2017 (n = 35), and 2018 (n = 35) were analyzed as composite samples for macro- and micronutrients using accredited methods at the Institute of Marine Research in Norway. Results: This study confirms that seafood products are good sources of several key nutrients, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), vitamin D, vitamin B12, iodine, and selenium. Fatty fish products had the highest content of EPA, DHA, and vitamin D, while lean fish products had the highest content of vitamin B12 and minerals. However, some lean fish products, such as one portion of fish au gratin or fish cakes, also proved as good sources of EPA, DHA, and vitamin D, and contributed substantially to the recommended intake. Variations in nutrients were seen both within the same product category and between the same product category from different years. Conclusions: These data give valuable insights into seafood products as a source of essential micronutrients and highlight the importance of these products for nutrition and health.publishedVersio

Intake of farmed Atlantic salmon fed soybean oil increases insulin resistance and hepatic lipid accumulation in mice

BACKGROUND: To ensure sustainable aquaculture, fish derived raw materials are replaced by vegetable ingredients. Fatty acid composition and contaminant status of farmed Atlantic salmon (Salmo salar L.) are affected by the use of plant ingredients and a spillover effect on consumers is thus expected. Here we aimed to compare the effects of intake of Atlantic salmon fed fish oil (FO) with intake of Atlantic salmon fed a high proportion of vegetable oils (VOs) on development of insulin resistance and obesity in mice. METHODOLOGY/PRINCIPAL FINDINGS: Atlantic salmon were fed diets where FO was partly (80%) replaced with three different VOs; rapeseed oil (RO), olive oil (OO) or soy bean oil (SO). Fillets from Atlantic salmon were subsequently used to prepare Western diets (WD) for a mouse feeding trial. Partial replacement of FO with VOs reduced the levels of polychlorinated biphenyls (PCB) and dichloro-diphenyl-tricloroethanes (DDT) with more than 50% in salmon fillets, in WDs containing the fillets, and in white adipose tissue from mice consuming the WDs. Replacement with VOs, SO in particular, lowered the n-3 polyunsaturated fatty acid (PUFA) content and increased n-6 PUFA levels in the salmon fillets, in the prepared WDs, and in red blood cells collected from mice consuming the WDs. Replacing FO with VO did not influence obesity development in the mice, but replacement of FO with RO improved glucose tolerance. Compared with WD-FO fed mice, feeding mice WD-SO containing lower PCB and DDT levels but high levels of linoleic acid (LA), exaggerated insulin resistance and increased accumulation of fat in the liver. CONCLUSION/SIGNIFICANCE: Replacement of FO with VOs in aqua feed for farmed salmon had markedly different spillover effects on metabolism in mice. Our results suggest that the content of LA in VOs may be a matter of concern that warrants further investigation

Dietary linoleic acid induces obesity through excessive endocannabinoid activity

Background: Dietary intakes of the n-6 fatty acid linoleic acid (LA, 18:2n-6) have increased dramatically during the 20th century. Replacing fish oil (FO) with vegetable oil (VO) in feed for farmed fish introduces LA and alters the fatty acid composition in Atlantic salmon (Salmo salar L.). LA is the precursor of arachidonic acid (AA, 20:4n-6) the backbone of the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (AEA). A sustained hyperactivity of the endocannabinoid system is believed to play a causal role in the development of obesity and associated metabolic disorders. Here we posit that excessive dietary intake of LA, the precursor of AA, would induce endocannabinoid hyperactivity and promote obesity. Design: LA was isolated as an independent variable to reflect the dietary increase in LA from 1 percent of energy (en%) to 8 en% occurring in the US during the 20th century. Male C57BL/6j mice were exposed to 1 en% LA and 8 en% LA in diets of 35 en% and 60 en% fat from last week of gestation and 14 weeks from weaning (Paper I), and in diets of 12.5 en% and 35 en% fat for 16 weeks from 6 weeks of age (Paper II). To reduce tissue n-6 highly unsaturated fatty acids (HUFA), 1 en% eicosapentaenoic acid (EPA, 20:5n-3)/docosahexaenoic acid (DHA, 22:6n-3) were supplemented to the 8 en% LA diets in Paper I. Atlantic salmon, 340 g, was fed fish oil and soybean oil (SO) for 6 months. Male C57BL76j mice, 6 weeks of age, were fed diets of 35 en% fat based on FO salmon fillet (1 en% LA) and SO salmon fillet (8 en% LA) for 16 weeks (Paper III). Results: Increasing dietary LA from 1 en% to 8 en% elevated AA in phospholipids (AA -PL) with a subsequent elevation in liver 2-AG and anandamide associated with higher food intake, feed efficiency, weight gain and adiposity and increased hypertrophy and inflammation of adipose tissue. Selectively reducing LA to 1 en% reversed the obesogenic properties of a high fat diet. Reducing AA -PL by EPA/DHA supplementation resulted in metabolic patterns resembling 1 en% LA diets. Replacing fish oil with soybean oil in feed for Atlantic salmon elevated tissue LA and AA, and increased endocannabinoid activity and lipid accumulation in salmon liver. Mice fed SO salmon gained more weight, had larger adipocytes and more adipose tissue inflammation than mice fed FO salmon. Conclusion: Dietary LA of 8 en% LA induces hyperactivity of the endocannabinoid system and increase the risk of developing obesity and associated metabolic disorders in mice. In a balanced diet, the adipogenic effect of LA can be prevented by consuming sufficient EPA and DHA to reduce the AA -PL pool and normalize endocannabinoid tone. A dietary approach addressing an underlying cause of endocannabinoid hyperactivity may prove to be a safe and viable alternative for preventing and decreasing obesity

Dietary linoleic acid elevates the endocannabinoids 2-AG and anandamide and promotes weight gain in mice fed a low fat diet

Dietary intake of linoleic acid (LNA, 18:2n-6) has increased dramatically during the 20th century and is associated with greater prevalence of obesity. The endocannabinoid system is involved in regulation of energy balance and a sustained hyperactivity of the endocannabinoid system may contribute to obesity. Arachidonic acid (ARA, 20:4n-6) is the precursor for 2-AG and anandamide (AEA), and we sought to determine if low fat diets (LFD) could be made obesogenic by increasing the endocannabinoid precursor pool of ARA, causing excessive endocannabinoid signaling leading to weight gain and a metabolic profile associated with obesity. Mice (C57BL/6j, 6 weeks of age) were fed 1 en% LNA and 8 en% LNA in low fat (12.5 en%) and medium fat diets (MFD, 35 en%) for 16 weeks. We found that increasing dietary LNA from 1 to 8 en% in LFD and MFD significantly increased ARA in phospholipids (ARA–PL), elevated 2-AG and AEA in liver, elevated plasma leptin, and resulted in larger adipocytes and more macrophage infiltration in adipose tissue. In LFD, dietary LNA of 8 en% increased feed efficiency and caused greater weight gain than in an isocaloric reduction to 1 en% LNA. Increasing dietary LNA from 1 to 8 en% elevates liver endocannabinoid levels and increases the risk of developing obesity. Thus a high dietary content of LNA (8 en%) increases the adipogenic properties of a low fat diet

New data on nutrient composition in large selection of commercially available seafood products and its impact on micronutrient intake

Background: Most foods, including seafood, undergo some sort of processing as an integrated part of the global food industry. The degree of processing depends on the type of product produced. Processed seafood products are an important part of the diet; thus, knowledge of nutrient content in seafood products is of great importance. Objective: The aim of this study was to describe the content of selected nutrients in commercially available and market representative seafood products purchased from 3 different years. Methods: Seafood products from 2015 (n = 16), 2017 (n = 35), and 2018 (n = 35) were analyzed as composite samples for macro- and micronutrients using accredited methods at the Institute of Marine Research in Norway. Results: This study confirms that seafood products are good sources of several key nutrients, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), vitamin D, vitamin B12, iodine, and selenium. Fatty fish products had the highest content of EPA, DHA, and vitamin D, while lean fish products had the highest content of vitamin B12 and minerals. However, some lean fish products, such as one portion of fish au gratin or fish cakes, also proved as good sources of EPA, DHA, and vitamin D, and contributed substantially to the recommended intake. Variations in nutrients were seen both within the same product category and between the same product category from different years. Conclusions: These data give valuable insights into seafood products as a source of essential micronutrients and highlight the importance of these products for nutrition and health

Fatty acid composition of the experimental mice diets.

<p>Data represent mean of duplicate measurements. Sum n−3 and sum n−6 include additional fatty acids not indicated in the table.</p><p>Abbreviations: ALA, α-linolenic acid; AA, arachidonic acid; DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid; LA, linoleic acid, MUFA, monounsaturated fatty acids; SFA, saturated fatty acids.</p

Fatty acid composition in salmon fillets influences development of insulin resistance in mice.

<p>Male C57BL/6J mice (n = 8/diet) were fed WD-FO, WD-RO, WD-OO and WD-SO for 10 weeks. As references, two groups of mice received regular WD or LF diet. Plasma glucose (A) and insulin (B) were measured after overnight fasting. An intraperitoneal glucose tolerance test (GTT) was performed after 7 weeks of feeding (C) and an intraperitoneal insulin tolerance test (ITT) was performed after 8 weeks of feeding (D). Area under the curve (AUC) was calculated from the glucose tolerance (baseline was set to fasted blood glucose levels) (E) and insulin tolerance test (F). Data are presented as means+SEM (n = 8). *represents significant different from WD-FO (P<0.05). **represents significant different from WD-FO (P<0.01). ***represents significant different from WD-FO (P<0.005).</p

Composition of salmon aqua feed changes accumulation of POPs in mice consuming the salmon fillets.

<p>Fish oil (FO) in aqua feed was partly replaced with rapeseed oil (RO), olive oil (OO) or soy bean oil (SO) and fed Atlantic salmon. The salmon fillets were used in Western diets (WDs) fed male C57BL/6J mice (n = 8/diet) for 10 weeks. Concentrations of 7PCBs and DDTs were measured in (A) Atlantic salmon fillets (B) the WDs containing the fillets and (C) epididymal white adipose tissue (eWAT) and (D) liver collected from mice consuming the WDs and a low fat reference diet. Data represent mean of duplicate measurements in A and B. Tissues from two animals were pooled to achieve sufficient material for POP analyzes, and data in C and D thus represent mean+SEM (n = 4). Asterisk(s) indicates significant different from WD-FO.</p

Fatty acid composition in RBCs from mice after consuming the experimental diets for 10 weeks.

<p>The n−3 index: EPA+ DHA content of erythrocytes expressed as a percent of total fatty acids in RBCs. Sum n−3 and sum n−6 include additional fatty acids not indicated in the table.</p><p>Data are presented as mean ± SEM (n = 5). Asterisk(s) indicates significant different from WD-FO.</p>*<p>p<0.05,</p>**<p>p<0.01,</p>***<p>p<0.005.</p><p>Abbreviations: AA, arachidonic acid; DHA, docosahexaenoic acid, EPA, eicosapentaenoic acid, FA, fatty acids; HUFA, highly unsaturated fatty acids (HUFA, ≥20 carbons and ≥3 carbon-carbon double bonds), LA, linoleic acid; MUFA, monounsaturated fatty acids; RBCs, red blood cells; SFA, saturated fatty acids.</p