Karl-Erik Eilertsen

Health benefits of marine foods and ingredients

The health benefits of seafood consumption have primarily been associated with protective effects against cardiovascular diseases (CVD). However, intake of seafood has also been associated with improved foetal and infant development, as well as several other diseases and medical conditions. The health promoting effects have chiefly been attributed to the long-chain n-3 polyunsaturated fatty acids (n-3 PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In addition, the general fatty acid profile is considered favourable. On the other hand, recent and emerging research on seafood proteins and other seafood derived components suggest that these nutritional components contribute to the health effects. In this paper we review the nutritional characteristics and health benefits of marine foods and ingredients, and discuss some current and future trends in marine food production.

Tissue factor: (patho)physiology and cellular biology.

The transmembrane glycoprotein tissue factor (TF) is the initiator of the coagulation cascade in vivo. When TF is exposed to blood, it forms a high-affinity complex with the coagulation factors factor VII/activated factor VIIa (FVII/VIIa), activating factor IX and factor X, and ultimately leading to the formation of an insoluble fibrin clot. TF plays an essential role in hemostasis by restraining hemorrhage after vessel wall injury. An overview of biological and physiological aspects of TF, covering aspects consequential for thrombosis and hemostasis such as TF cell biology and biochemistry, blood-borne (circulating) TF, TF associated with microparticles, TF encryption–decryption, and regulation of TF activity and expression is presented. However, the emerging role of TF in the pathogenesis of diseases such as sepsis, atherosclerosis, certain cancers and diseases characterized by pathological fibrin deposition such as disseminated intravascular coagulation and thrombosis, has directed attention to the development of novel inhibitors of tissue factor for use as antithrombotic drugs. The main advantage of inhibitors of the TF•FVIIa pathway is that such inhibitors have the potential of inhibiting the coagulation cascade at its earliest stage. Thus, such therapeutics exert minimal disturbance of systemic hemostasis since they act locally at the site of vascular injury.

Enhanced Incorporation of n-3 Fatty Acids from Fish Compared with Fish Oils

This work was undertaken to study the impact of the source of n−3 FA on their incorporation in serum, on blood lipid composition, and on cellular activation. A clinical trial comprising 71 volunteers, divided into five groups, was performed. Three groups were given 400 g smoked salmon (n=14), cooked salmon (n=15), or cooked cod (n=13) per week for 8 wk. A fourth group was given 15 mL/d of cod liver oil (CLO) (n=15), and a fifth group served as control (n=14) without supplementation. The serum content of EPA and DHA before and after intervention revealed a higher rise in EPA and DHA in the cooked salmon group (129% rise in EPA and 45% rise in DHA) as compared with CLO (106 and 25%, respectively) despite an intake of EPA and DHA in the CLO group of 3.0 g/d compared with 1.2 g/d in the cooked salmon group. No significant changes were observed in blood lipids, fibrinogen, fibrinolysis, or lipopolysaccharide (LPS)-induced tissue factor (TF) activity, tumor necrosis factor-α (TNFα), interleukin-8 (IL-8), leukotriene B4 (LTB4), and thromboxane B2 (TxB2) in whole blood. EPA and DHA were negatively correlated with LPS-induced TNFα, IL-8, LTB4, TxB2, and TF in whole blood. In conclusion, fish consumption is more effective in increasing serum EPA and DHA than supplementing the diet with fish oil. Since the n−3 FA are predominantly in TAG in fish as well as CLO, it is suggested that the larger uptake from fish than CLO is due to differences in physiochemical structure of the lipids.

Characterization of protein, lipid and mineral contents in common Norwegian seaweeds and evaluation of their potential as food and feed

BACKGROUND The objectives of this study were to examine protein and amino acid composition, lipid and fatty acid composition, along with a range of essential minerals in common Norwegian seaweed species representing the red (Palmaria palmata and Vertebrata lanosa), green (Cladophora rupestris, Enteromorpha intestinalis and Ulva lactuca) and brown (Alaria esculenta, Laminaria digitata, Laminaria hyperborea, Fucus vesiculosus and Pelvetia canaliculata) classes and assess their potential as alternatives to cereals in food and feed. As macroalgae accumulate heavy metals, arsenic, cadmium and mercury were also analyzed. RESULTS Proteins ranged from 34 to 123 g kg(-1) dry weight (DW) and the essential amino acid levels may cover both human and salmonid requirements. Lipids were low (6-58 g kg(-1) DW), but the red algae had high relative content of long-chained omega-3 fatty acids (32-34 % of the fatty acids). Iodine contents were particularly high in the Laminaria species. Of the heavy metals only arsenic levels may be of concern. CONCLUSION In total, the red alga P. palmata was regarded as the best alternative to cereals in food and feed. For several of the other species, single-component extraction for the ingredients market may be better than using the whole product.

Seafood diets: hypolipidemic and antiatherogenic effects of taurine and n-3 fatty acids.

BACKGROUND Health aspects of seafood have primarily been linked to n-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Although animal studies have suggested beneficial contributions from taurine, highly abundant in seafood, its effect in humans is obscure. This study evaluates the combined effects of n-3 PUFA and taurine. METHODS Healthy volunteers (n=80) were recruited to a 7-week double-blind and parallel intervention trial. One group (n=39) received fish pâté (36g/day) enriched in n-3 (1.1gEPA+DHA/day) and the second (n=41) an identical pâté enriched both in n-3 and taurine (425mg/day). RESULTS Total cholesterol (TC) (-5%, P<0.001), low-density lipoprotein (LDL)-cholesterol (-8%, P<0.001) and Apo B (-4%, P<0.001) decreased more in the n-3+taurine compared to the n-3 group. A significant within-group enhancement of high-density lipoprotein (HDL)-cholesterol was demonstrated in the n-3+taurine group (6%, P<0.0001). Reductions in triacylglycerol (TG) (-16%, P<0.05 in n-3; -14%, P<0.05 in n-3+taurine), thromboxane B(2) (TxB(2)) (-21%, P<0.001 in n-3; -15%, P<0.05 in n-3+taurine), tumor necrosis factor (TNFalpha) (-24%, P<0.001 in n-3; -12%, P<0.05 in n-3+taurine) and monocyte chemotactic protein (MCP-1) (-12%, P<0.05 in n-3; -6%, P<0.0001 in n-3+taurine) were evident in both groups. Reductions in interleukin (IL)-6 (-16%, P<0.05) and LTB(4) (-18%, P<0.05) were only significant in the n-3 group. CONCLUSIONS The effects, particularly on blood lipids, of combining n-3 PUFAs and taurine proved superior to those of n-3 alone.

ω-3 Fatty Acids and Cardiovascular Diseases: Effects, Mechanisms and Dietary Relevance.

ω-3 fatty acids (n-3 FA) have, since the 1970s, been associated with beneficial health effects. They are, however, prone to lipid peroxidation due to their many double bonds. Lipid peroxidation is a process that may lead to increased oxidative stress, a condition associated with adverse health effects. Recently, conflicting evidence regarding the health benefits of intake of n-3 from seafood or n-3 supplements has emerged. The aim of this review was thus to examine recent literature regarding health aspects of n-3 FA intake from fish or n-3 supplements, and to discuss possible reasons for the conflicting findings. There is a broad consensus that fish and seafood are the optimal sources of n-3 FA and consumption of approximately 2–3 servings per week is recommended. The scientific evidence of benefits from n-3 supplementation has diminished over time, probably due to a general increase in seafood consumption and better pharmacological intervention and acute treatment of patients with cardiovascular diseases (CVD).

The role of blood cells and their microparticles in blood coagulation

The transmembrane glycoprotein TF (tissue factor) plays an essential role in haemostasis as the principal initiator of blood coagulation. In this paper, we describe how the circulating blood cells--monocytes, platelets, neutrophils and their microparticles--co-operate in regulating the expression, availability and activity of monocyte-derived TF.

Antioxidant and Anti-Inflammatory Activities of Barettin

In this paper, we present novel bioactivity for barettin isolated from the marine sponge Geodia barretti. We found that barettin showed strong antioxidant activity in biochemical assays as well as in a lipid peroxidation cell assay. A de-brominated synthetic analogue of barettin did not show the same activity in the antioxidant cell assay, indicating that bromine is important for cellular activity. Barettin was also able to inhibit the secretion of the inflammatory cytokines IL-1β and TNFα from LPS-stimulated THP-1 cells. This combination of anti-inflammatory and antioxidant activities could indicate that barettin has an atheroprotective effect and may therefore be an interesting product to prevent development of atherosclerosis.

The central role of thromboxane and platelet activating factor receptors in ex vivo regulation of endotoxin-induced monocyte tissue factor activity in human whole blood.

Expression of tissue factor (TF) by activated monocytes may initiate thrombotic episodes associated with diseases, such as thrombosis and atherosclerosis. In this study, steps in the regulatory pathways of lipopolysaccharide (LPS)-induced monocyte TF activity and released TNF-α in human whole blood were probed for using an array of inhibitors, comprising specific inhibitors of cytosolic phospholipase A2 (PLA2) (AACOCF3), secretory PLA (SB-203347), protein kinase (PK) (staurosporine), PKC (GF109203; BIM), and serine protease (Pefabloc SC), antagonists of thromboxane prostanoid (TP) receptor (R) (SQ-29548), platelet activating factor (PAF) R (BN-52021), leukotriene B4 R (SC-41930), serotonin R (cyproheptadine), fibronectin/fibrinogen R (RGDS), and finally, creatine phosphate/creatine phosphokinase (CP/CPK) which removes ADP. Whereas when added alone neither of these agents significantly inhibited LPS-induced TF or TNF-α, when presented as a reference cocktail comprising all the agents, TF activity and TNF-α were reduced by 77% and 49%, respectively. By subsequently testing a series of incomplete inhibitory cocktails equal to the reference except for deleted single agents or combinations of two or three active agents, the inhibitory effect of the reference cocktail could be shown to depend on the presence of the protease inhibitor and the thromboxane A2 and PAF antagonists.

A Wax Ester and Astaxanthin-Rich Extract from the Marine Copepod Calanus finmarchicus Attenuates Atherogenesis in Female Apolipoprotein E–Deficient Mice

The aim of this study was to investigate the effect of dietary supplementation with an oil extracted from the zooplankton copepod Calanus finmarchicus [calanus oil (CO)] on atherosclerosis in apoE-deficient (apoE(-/-)) mice. Thirty 6-wk-old female apoE(-/-) mice (n = 10/group) were fed: 1) a Western-type, high-fat diet (HFD); 2) HFD supplemented with 1% (wt:wt) CO; or 3) HFD supplemented with 0.88% (wt:wt) corn oil + 0.12% (wt:wt) EPA+DHA ethyl esters (EPA+DHA) for 13 wk. Dietary CO supplementation lowered total aorta atherogenesis by 36.5% compared to the HFD (P < 0.01), whereas the reduction in the lesion prone aortic arch was 34.8% (P < 0.01). The degree of aortic atherogenesis was intermediate in mice fed EPA+DHA compared to those fed HFD and CO. The effect on atherogenesis was paralleled by reduced expression of hepatic genes for the proinflammatory cytokines, Ccl2, Icam1, Il1b, and Nfkb1, in mice fed CO compared to those fed HFD. For mice fed EPA+DHA, gene expression did not differ compared to those fed CO or HFD. Plasma concentrations of total cholesterol, TG, and cytokines did not differ between the groups at the end of the study. However, mice fed CO gained more weight compared to those fed HFD but not compared to those fed EPA+DHA. In conclusion, dietary CO supplementation attenuated atherosclerotic lesion formation in female apoE(-/-) mice and may be an effective and safe dietary intervention to reduce the development of atherosclerosis. However, further studies are warranted to elucidate the underlying physiological and molecular mechanisms.