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).

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.

Enzymatic Hydrolysis of Orange-Footed Sea Cucumber (Cucumaria frondosa)-Effect of Different Enzymes on Protein Yield and Bioactivity.

While sea cucumber is a food delicacy in Asia, these food resources are less exploited in Europe. The aim of this study was to determine the chemical composition and potential food applications of the less exploited orange-footed sea cucumber (Cucumaria frondosa). In particular, the antioxidative capacity and free amino acids associated with the umami flavor released by enzymatic hydrolyses by either Bromelain + Papain (0.36%, 1:1) or Alcalase (0.36%) were studied. Fresh C. frondosa contained approximately 86% water, and low levels of ash (<1%) and lipids (<0.5%). The protein content was 5%, with a high proportion of essential amino acids (43%) and thus comparable to the FAO reference protein. The high concentration of free amino acids associated with umami, sour, sweet, and bitter may contribute to flavor enhancement. Hydrolysis by Bromelain + Papain resulted in the highest protein yield, and the greatest concentration of free amino acids associated with umami and sour taste. All samples showed promising antioxidant capacity measured by FRAP, ABTS, DPPH and ORAC compared to previous reports. The inorganic arsenic concentration of fresh C. frondosa ranged from 2 to 8 mg/kg wet weight and was not affected by processing. This is comparable to other seafood and may exceed regulatory limits of consumption.

Associations between serum taurine concentrations in mothers and neonates and the children's anthropometrics and early neurodevelopment: Results from the Seychelles Child Development Study, Nutrition Cohort 2.

BACKGROUND: High concentrations of taurine are present in the developing human brain and maternal breast milk. Taurine is thought to influence fetal growth and brain development based on experimental rodent studies. As fish is an important dietary source of taurine, we investigated associations between taurine concentrations and child outcomes in a high fish consuming population. OBJECTIVE: To examine associations between maternal and cord serum taurine concentrations and birth anthropometric measures and cognitive development in children at 20 months of age. METHODS: Pregnant women were recruited between 2008 and 2011 as part of Nutrition Cohort 2 (NC2) of the Seychelles Child Development Study (SCDS). Maternal taurine serum concentrations were measured at 28 week's gestation and in cord serum. Child weight, length and head circumference were measured at birth and neurodevelopment was assessed using Bayley Scales of Infant Development II (BSID-II) at 20 months of age. Associations between taurine status, birth measures and neurodevelopmental outcomes were examined (n = 300) using regression models and adjusted for relevant covariates. RESULTS: Mean (SD) maternal and cord taurine concentrations were 124.9 (39.2) µmol/L (range 28.2-253.9 µmol/L) and 187.6 (60.0) µmol/L (range 55.0-417.4 µmol/L) respectively. We found no associations between maternal taurine concentrations and child anthropometric and neurodevelopmental measures (weight ß = -0.001, SE=0.001; length ß = -0.006, SE=0.006; head circumference ß = -0.002, SE=0.002; MDI ß = -0.005, SE=0.015; PDI ß = -0.004, SE=0.016; all P > 0.05), or between cord taurine concentrations and outcomes (weight ß = -0.001, SE<0.000; length ß = -0.001, SE=0.004; head circumference ß < 0.000, SE=0.002; MDI ß = 0.004, SE=0.010; PDI ß = -0.015, SE=0.012; all P > 0.05). CONCLUSION: The Seychellois population have high maternal and cord taurine concentrations owing to their high fish intake and may be considered taurine replete compared to individuals who consume a Westernised diet. This high taurine status may explain why there were no significant associations between maternal and cord taurine concentrations and outcomes after adjusting for covariates.

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.

Climate Performance, Environmental Toxins and Nutrient Density of the Underutilized Norwegian Orange-Footed Sea Cucumber (Cucumaria frondosa).

Low trophic species are often mentioned as additional food sources to achieve broader and more sustainable utilisation of the ocean. The aim of this study was to map the food potential of Norwegian orange-footed sea cucumber (Cucumaria frondosa). C. frondosa contained 7% protein, 1% lipids with a high proportion of polyunsaturated fatty acids, and a variety of micronutrients. The nutrient density scores (NDS) of C. frondosa were above average compared towards daily recommended intakes (DRI) for men and women (age 31-60) but below when capped at 100% of DRI. The concentrations of persistent organic pollutants and trace elements were in general low, except for inorganic arsenic (iAs) (0.73 mg per kg) which exceeded the limits deemed safe by food authorities. However, the small number of samples analysed for iAs lowers the ability to draw a firm conclusion. The carbon footprint from a value chain with a dredge fishery, processing in Norway and retail in Asia was assessed to 8 kg carbon dioxide equivalent (CO2eq.) per kg C. frondosa, the fishery causing 90%. Although, C. frondosa has some nutritional benefits, the carbon footprint or possible content of iAs may restrict the consumption.

Impact of processing on the taurine content in processed seafood and their corresponding unprocessed raw materials.

Processing of foods can lead to losses of water-soluble components, and some of these may have beneficial health effects. Taurine has lately attracted attention due to its suggested strong contribution to the health-promoting effects of seafood. The lack of systematic information on the content of conditionally essential nutrients, such as taurine, has led to this study. The taurine concentrations in a variety of common marine dinners and spreads, and their corresponding raw materials, have been determined. Losses of taurine in processed products ranged up to 100% when compared with the taurine content of freshly caught specimens. Products soaked in brines or products subjected to rough processing conditions such as mincing and washing had greater loss compared with products with more intact muscle. Levels of taurine in processed seafood vary according to product type and brand, showing a potential for the industry to take measures in preventing losses of taurine and other water-soluble components.

Protein Determination-Method Matters.

The reported protein content of foods depends on the analytical method used for determination, making a direct comparison between studies difficult. The aim of this study was to examine and compare protein analytical methods. Some of these methods require extraction preceding analysis. The efficacy of protein extraction differs depending on food matrices and thus extraction yield was determined. Overall, most analytical methods overestimated the protein contents. The inaccuracies were linked to indirect measurements, i.e. nitrogen determination and subsequent conversion to protein, or interference from other chemical substances. Amino acid analysis is the only protein analysis method where interfering substances do not affect the results. Although there is potential for improvement in regards to the hydrolysis method, we recommend that this method should be the preferred for food protein determination.

Cold-pressed minke whale oil reduces circulating LDL/VLDL-cholesterol, lipid oxidation and atherogenesis in apolipoprotein E-deficient mice fed a Western-type diet for 13 weeks.

BACKGROUND: Long-chain n3-polyunsaturated fatty acids (LC n3-PUFA) are well known for their anti-inflammatory activity and their impact on cardiovascular disease. Cold-pressed whale oil (CWO) has half the amount of LC n3-PUFA compared to cod liver oil (CLO). Still, there has been observed more pronounced beneficial effects on cardiovascular disease markers from intake of CWO compared to intake of CLO in human intervention studies. Extracts from CWO deprived of fatty acids have also been shown to display antioxidative and anti-inflammatory effects in vitro. The aim of this study was to investigate whether intake of a high-fat Western-type diet (WD) supplemented with CWO would prevent the development of atherosclerotic lesions in apolipoprotein E-deficient (ApoE-/-) mice. METHODS: Seventy female ApoE-/- mice were fed a WD containing 1% CWO, CLO or corn oil (CO). Atherosclerotic lesion formation, body and tissue weights, hepatic gene expression together with serum levels of LDL/VLDL-cholesterol, ox-LDL, total antioxidant status and various serum cardiovascular disease/proinflammatory markers were evaluated. Statistical analyses were performed using SPSS, and Shapiro-Wilk's test was performed to determine the distribution of the variables. Statistical difference was assessed using One-Way ANOVA with Tukeys' post hoc test or Kruskal-Wallis test. The hepatic relative gene expression was analysed with REST 2009 (V2.0.13). RESULTS: Mice fed CWO had less atherosclerotic lesions in the aortic arch compared to mice fed CO. Levels of LDL/VLDL-cholesterol and ox-LDL-cholesterol were also markedly reduced whereas total antioxidant levels were enhanced in mice fed CWO compared to CO-fed mice. In addition, CWO-fed mice gained less weight and several hepatic genes involved in the cholesterol metabolism were up-regulated compared to CO-fed mice. CONCLUSION: In the present study mice fed a WD supplemented with 1% CWO had reduced formation of atherosclerotic lesions in the aortic arch, reduced serum LDL/VLDL-cholesterol and ox-LDL-cholesterol, increased serum total antioxidant status and reduced body weight compared to mice fed a WD supplemented with 1% CO.

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-alpha (TNFalpha), interleukin-8 (IL-8), leukotriene B4 (LTB4), and thromboxane B2 (TxB2) in whole blood. EPA and DHA were negatively correlated with LPS-induced TNFalpha, 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.

Dietary intake of cod and scallop reduces atherosclerotic burden in female apolipoprotein E-deficient mice fed a Western-type high fat diet for 13 weeks.

BACKGROUND: It is now increasingly recognized that the beneficial effects of seafood consumption is not limited to lipids and fatty acid, but that the protein part, i.e., peptides and amino acids, together with vitamins and even unknown bioactive constituents also are important for disease prevention. This study was designed to evaluate the putative anti-atherogenic effects of different protein sources (a lean seafood and a nonseafood) in apolipoprotein E-deficient (apoE(-/-)) mice. METHODS: Twenty-four 5-week-old female apoE(-/-) mice were fed Western type diets containing chicken or a combination of cod and scallops as dietary protein sources for 13 weeks. Atherosclerotic plaque burden, weight, serum levels of leptin, glucose and LDL cholesterol as well as gene expressions from liver and heart were evaluated. Statistical analyses were performed using SPSS. Differences between the variables were evaluated using independent t-test or Mann-Whitney U test for normally and non-normally distributed variables, respectively. Normality was defined by the Shapiro-Wilk test. RESULTS: The mice fed cod-scallop had a 24 % (p < 0.05) reduced total aorta atherosclerotic plaque burden compared to the chicken fed group, whereas the reduction in plaque in the less lesion prone thoracic and abdominal parts of the descending aorta were 46 % (p < 0.05) and 56 % (p < 0.05), respectively. In addition, mice fed cod-scallop gained less weight, and had lower serum levels of leptin, glucose and LDL cholesterol, compared to those fed chicken. Analysis of expression of the genes from liver and heart showed that hepatic endogenous antioxidant paraoxonase 2 (Pon2 gene) and the vascular cell adhesion molecule VCAM-1 (Vcam1 gene) were down regulated in mice fed cod-scallop compared to mice fed chicken. CONCLUSION: The present study revealed a metabolic beneficial effect of lean seafood compared to chicken, as atherosclerotic plaque burden, serum glucose, leptin and LDL cholesterol levels were reduced in mice fed cod-scallop.

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.

Changes in antioxidative capacity of saithe (Pollachius virens) and shrimp (Pandalus borealis) during in vitro digestion.

The health effects of seafood have primarily been linked to eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3). These omega-3 fatty acids are highly susceptible to oxidation. Peptides exhibiting antioxidative capacity (AOC) are encrypted in seafood muscle proteins. Such components may protect the fatty acids during digestion and uptake, as well as exhibit antioxidative effects in general. The oxygen radical absorbance capacity (ORAC) assay and the ferric reducing antioxidant power (FRAP) assay were used to study the changes in AOC of fish and shrimp muscle and their aqueous fractions, referred to as press juice (PJ), during a simulated in vitro gastrointestinal (GI) digestion. Blueberry (Vaccinium myrtillus), well-known for its AOC, was included for comparison. During digestion the AOC increased in all samples. After digestion the AOC of muscle of both autumn saithe and shrimp were higher (130-165 micromol/g), and winter saithe comparable (110 micromol/g) to digested blueberry when measured by ORAC. The AOC of PJ was low in general (5-20 micromol/g). When measured by FRAP, blueberry exhibited ten times the AOC of seafood muscle. Antioxidative compounds in seafood increased significantly during digestion, and may offer protection of other beneficial food components such as EPA and DHA.

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 PUFA's and taurine proved superior to those of n-3 alone.

Impact of processing on nutritional quality of marine food items.

During the last two decades it has been established that Greenland Eskimos living on their traditional diet, have a lower incidence of coronary heart disease (CHD) than when living in Denmark on a western diet. These findings have been attributed to their diet, particularly the high amounts n-3 polyunsaturated fatty acids. The Eskimo diet consists mainly of meat and blubber of seal and whale and relatively small amounts of fish. Another aspect of the Eskimo diet, still not fully explored, is that the Eskimos consume the bulk of their food raw or dried, seldom boiled or exposed to excessive heat. The main task of modern processes is to make edible and stable products. Removal of molecules that cause off-flavours or taste to improve sensory attributes may, for instance, destroy potent antioxidants. Modern meal preparing techniques may also lower the content of biologically active components. The objective of our experiments has been, by mimicking in part the traditional Eskimo diet, to explore the beneficial effects of raw food items on parameters related to development of CHD. Reduced tendency of developing arteriosclerosis has been related to the lower reactivity of platelets and less production of proinflammatory products, e.g. cytokines, prostaglandins and leukotrienes. In our study, healthy volunteers ingested raw or heat processed marine materials (smoked versus heat processed salmon muscle, cold pressed versus refined marine oils).