[Study of indices for the objective evaluation of medicinal cod liver oil quality].
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Fish Oils↗
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[Various methods in the determination of the rancidity of cod liver oil].
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Fish Oils↗
Dietary influence of a cod liver oil fraction on avian lymphocytoma.
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Animals↗
Effect of dietary lipids on growth, tissue composition and metabolism of the oyster (Crassostrea virginica).
Hatchery reared oysters (Crassostrea virginica) were fed six different diets for 30 weeks. The diets contained cod liver oil (CLO), corn oil (CO), corn oil and cod liver oil (1:2) (CO + CLO), hyrogenated coconut oil (HCO), ethyl esters of cod liver oil fatty acids (SF) or cod liver oil ethyl esters supplemented with cholesterol (CH). Data on growth and tissue composition imply that oysters have an essential fatty acid (EFA) requirement for both linolenic or omega 3 and linoleic or omega 6 series fatty acids, with the former playing a more significant role. The feeding study supported by a 14C-acetate metabolism experiment suggests that these oysters were unable to synthesize sterols and excessively high dietary sterol (1% of the dry weight of the diet) inhibited growth.
Animals↗
Study of diet and drug interactions on prostanoid metabolism.
To study the extent to which combinations of different dietary lipids stimulate or inhibit prostanoid synthesis groups of 12 rats were fed diets containing 10% (w/w) of either safflower oil, hydrogenated coconut oil/safflower oil, cod liver oil/safflower oil or cod liver oil/linseed oil for a period of four weeks. All diets, with the exception of the safflower oil feed, contained similar levels of linoleic acid. Two further groups of rats placed on the cod liver oil diets were injected with indomethacin (4 mg/kg, i.p.) every three days to establish the completeness of dietary prostaglandin (PG) inhibition. In spite of a 20 fold difference in dietary linoleic acid content, the safflower oil group had similar PG generating capacities to the saturated fat control group, suggesting tight metabolic control of PGs and their precursors. Although there were prostanoid variations in tissue responses, both of the cod liver oil diets substantially reduced generation of aortic, whole blood and renal prostanoids, and decreased urinary PG excretion. The degree of inhibition of renal PGs was substantially greater in the cod liver oil/linseed oil group, with prostaglandin levels being 35% lower than those observed in the cod liver oil/safflower oil fed animals suggesting that linolenic acid and the marine oil fatty acids act synergistically to inhibit formation of 2-series prostaglandins. Concurrent administration of omega-3 fatty acids and indomethacin reduced PG levels further than those obtainable by diet alone, demonstrating that the diets did not result in maximal inhibition. Awareness of these various effects is important for both physiological or clinical studies in which dietary manipulations are used as a means of modifying prostanoid synthesis.
Animals↗
Quantitative determination of total lipid hydroperoxides by a flow injection analysis system.
A flow injection analysis (FIA) system coupled with a fluorescence detection system using diphenyl-1-pyrenylphosphine (DPPP) was developed as a highly sensitive and reproducible quantitative method of total lipid hydroperoxide analysis. Fluorescence analysis of DPPP oxide generated by the reaction of lipid hydroperoxides with DPPP enabled a quantitative determination of the total amount of lipid hydroperoxides. Use of 1-myristoyl-2-(12-((7-nitro-2-1,3-benzoxadiazol-4-yl)amino) dodecanoyl)-sn-glycero-3-phosphocholine as the internal standard improved the sensitivity and reproducibility of the analysis. Several commercially available edible oils, including soybean oil, rape-seed oil, olive oil, corn oil, canola oil, safflower oil, mixed vegetable oils, cod liver oil, and sardine oil were analyzed by the FIA system for the quantitative determination of total lipid hydroperoxides. The minimal amounts of sample oils required were 50 microg of soybean oil (PV = 2.71 meq/kg) and 3 mg of sardine oil (PV = 0.38 meq/kg) for a single injection. Thus, sensitivity was sufficient for the detection of a small amount and/or low concentration of hydroperoxides in common edible oils. The recovery of sample oils for the FIA system ranged between 87.2+/-2.6% and 102+/-5.1% when PV ranged between 0.38 and 58.8 meq/kg. The CV in the analyses of soybean oil (PV = 3.25 meq/kg), cod liver oil (PV = 6.71 meq/kg), rapeseed oil (PV = 12.3 meq/kg), and sardine oil (PV = 63.8 meq/kg) were 4.31, 5.66, 8.27, and 11.2%, respectively, demonstrating sufficient reproducibility of the FIA system for the determination of lipid hydroperoxides. The squared correlation (r2) between the FIA system and the official AOCS iodometric titration method in a linear regression analysis was estimated at 0.9976 within the range of 0.35-77.8 meq/kg of PV (n = 42). Thus, the FIA system provided satisfactory detection limits, recovery, and reproducibility. The FIA system was further applied to evaluate changes in the total amounts of lipid hydroperoxides in fish muscle stored on ice.
Animals↗
White sturgeon tissue fatty acid compositions are affected by dietary lipids.
Juvenile white sturgeon (Acipenser transmontanus) were fed eight isonitrogenous and isoenergetic purified diets for 9 wk to study their ability to utilize different dietary lipids. Each diet contained 15% of control oil mixture (corn oil-cold liver oil-lard, 1:1:1), corn oil, cod liver oil, lard, linseed oil, soybean oil, safflower oil or canola oil. No significant (P > 0.05) differences in percentage of body weight increase, feed efficiency or body composition were observed among sturgeon fed the different lipids. Tissue fatty acid compositions most sensitive to dietary lipids were those of muscle and liver, whereas brain fatty acid composition was the least sensitive. Results of this study indicate that it is possible to increase the levels of (n-3) polyunsaturated and highly unsaturated fatty acids in sturgeon muscle by feeding the fish lipids high in these fatty acids for 9 wk.
Animals↗
Reversible alterations in fatty acid composition of heart muscle membrane phospholipids induced by epinephrine in rats fed different fats.
The effect of epinephrine on the fatty acid composition of heart muscle phospholipids was examined in rats fed diets containing 10% by weight of butter, corn oil, or cod liver oil. Repeated administration of epinephrine caused elevation of docosahexaenoic acid in phosphatidylcholine and phosphatidylethanolamine and a corresponding decrease in linoleic acid content. Arachidonic acid was increased in phosphatidylcholine and decreased or unaltered in phosphatidylethanolamine. These alterations were qualitatively similar despite different initial levels of fatty acids due to different dietary fats. The initial level of arachidonic acid in phosphatidylcholine and phosphatidylethanolamine was more than 50% lower in the rats fed cod liver oil than in rats fed butter and was partially replaced by the (n-3) fatty acids docosahexaenoic and eicosapentaenoic acid. Dietary corn oil produced less changes in fatty acid composition than cod liver oil compared to the reference diet, 10% butter. The results demonstrate that repeated administration of epinephrine caused significant alterations in fatty acid composition of major phospholipids in heart muscle of rats fed diets enriched with either butter, corn oil, or cod liver oil.
Animals↗
Effects of dietary lipids on whole-body retention and organ distribution of organic and inorganic mercury in mice.
The effect has been investigated of dietary lipids on the whole-body retention and organ distribution of organic and inorganic mercury in mice. A single oral dose of methylmercury chloride or mercuric chloride labelled with 203Hg was given to female NMRI mice fed semi-synthetic diets containing varying amounts (5, 10, 20 or 50%) of energy derived from lipid (coconut oil, soya oil, or cod liver oil). The whole-body retention and relative organ distribution of mercury depended on diet composition. Thus, a significant reduction of the whole-body retention of mercury was seen in mice fed a diet containing 50% cod liver oil compared with mice fed a diet containing 50% coconut oil. After oral administration of mercuric chloride the relative deposition of mercury in the kidneys increased while that in the liver decreased with increasing concentrations of soya oil or coconut oil in the diet. The whole-body retention of mercury after treatment with methylmercury chloride was significantly decreased in mice fed cod liver oil compared with mice fed coconut oil; there was no difference between mice fed cod liver oil and those fed soya oil. The relative disposition of mercury was significantly higher in all organs of mice fed a diet containing 20% energy from cod liver oil compared with mice fed a diet containing 20% energy from soya oil. The present study demonstrates that diet composition is of major importance to the toxicokinetics of methylmercury and mercuric mercury.
Administration, Oral↗
Effect of dietary fats on experimental hypertension.
In an experiment on 95 Wistar rats weighing 330 g the effect was studied of partially hydrogenated marine oil and cod-liver oil as well as sunflowerseed oil and animal fat on arterial hypertension induced with administration of 1.5% NaCl in drinking water. During 5 weeks the animals received diets containing 37.8 kcal% derived from the studied fats. After the first week of 1.5% NaCl solution administration a significant rise of the systolic blood pressure and heart rate was observed in all animals without regard to the fat received by them with the diet. The rise of the blood pressure was greatest in the group of rats kept on the diet with animal fat, while in the groups of rats receiving diets with sunflowerseed oil or marine oils this rise was significantly smaller, especially with cod-liver oil. The hypotensive effect of marine oils, particularly cod-liver oil, was more pronounced than that of sunflowerseed oil. The hypotensive effect of partially hydrogenated fish oil was less pronounced than that of cod-liver oil. Our experiments demonstrated a significant effect of the amount of dietary fat on the development of experimental hypertension. Greater intake of salt and animal fats in human diet may be one of the causes of essential hypertension.
Animals↗
Dietary modification of fatty acid and prostaglandin synthesis in the rat. Effect of variations in the level of dietary fat.
Dietary supplements with safflower oil, linseed oil, cod liver oil and hydrogenated coconut oil were given to rats at levels of 5, 20 and 40 energy % to simultaneously assess the effects of both type and level of dietary fat on tissue fatty acid composition and prostanoid synthesis. There was no significant change in weight gain or blood pressure between the dietary groups after the 4-week dietary regimen. The liver oil and linseed oil diets depressed the arachidonic acid content of kidney phospholipids at all levels of supplementation. The arachidonic acid content of plasma lipids was significantly elevated in animals on the safflower oil diet at 20 and 40 energy % while those on the same level of liver oil diet showed a marked reduction in arachidonic acid. Whole blood synthesis of thromboxane B2 varied significantly at all levels of fat supplementation, with the 20 energy % safflower oil fed group showing maximally enhanced thromboxane B2 production compared to the coconut oil group (P less than 0.001). Conversely, the liver oil groups showed depressed thromboxane B2 synthesis at 20 and 40 energy % (P less than 0.01) compared to the coconut oil group and at 5 energy % compared to the safflower oil group (P less than 0.05). Production of 6-ketoprostaglandin F1 alpha and prostaglandin E2 by incubated kidney homogenates only differed significantly between the dietary groups at 40 energy %. Urinary excretion of 6-ketoprostaglandin F1 alpha was increased by 45% and 55% in rats fed the safflower oil diet at 20 and 40 energy %, respectively compared to the saturated fat diet, while in the liver oil groups excretion was reduced by 20% and 32%. Dietary suppression of prostanoid synthesis is explained in part by changes in available arachidonic acid and competitive inhibition of cyclooxygenase by (n - 3) fatty acids. Thus, minor changes in dietary fat can readily alter tissue fatty acid composition, but both the extent and nature of changes in phospholipid and prostanoid metabolism vary markedly according to the tissue site.
6-Ketoprostaglandin F1 alpha↗
[Addition of various types of fat to mixed dry feed as influencing the growth rate and the level of food utilization in rainbow trout (salmo gairdneri)].
Commercially prepared mixtures of dry feed for trout were supplemented with sunflower oil, cod liver oil or emulsions of fish oil in amount of about 5% and were fed to hatchery rainbow trout (Salmo gairdneri) for an experimental period of 112 days at water temperatures ranging from 13 degrees to 20 degrees C. The fish receiving the fatted pellets were clearly superior to the controls in regard of rate of gain, food utilization and protein utilization. The best results were obtained with additions of sunflower oil. In this case, the rate of gain was 382% as compared with 262% (for the controls), food consumption per weight gain of fish was 1.28 compared with 1.98, PER 2.04 compared with 1.26 and PPW (productive protein value) 34.5 relative to 22.4. Additions of fat to the feed increased the fat content of the experimental fish by about 3%, raising it to an average total of 11.5%. The same effect had already been observed in a previous trial as a result of a 10% addition of sunflower oil.
Animal Feed↗
[Infant nutrition in Norway in the light of recent research].
Broadly speaking, infant nutrition in Norway is good during the first six months. Fortunately breast feeding is very common. In the second half of the first year, however, our infant nutrition is not quite in accord with recent research. The iron intake is less than recommended, and in many infants the iron status at one year of age is not satisfactory, although serious degrees of iron deficiency anemia are rare. Many infants are given cow's milk from six months of age, and thus receive more protein and electrolytes than desirable. This represents an unnecessary load on metabolism, fluid balance and kidneys, with too high "potential renal solute load". Insulin secretion is stimulated to a higher degree than with breast milk, and there is also some blood loss in the stools. The author emphasizes the importance of essential unsaturated fatty acids, particularly the fatty acids in marine oils (cod liver oil), and proposes a simple and inexpensive adjustment of Norwegian infant nutrition.
Humans↗
Identification of N alpha-acetyl-epsilon-(2-propenal)lysine as a urinary metabolite of malondialdehyde.
Although orally administered malondialdehyde (MDA), a reactive hepatotoxic and mutagenic product of lipid peroxidation, is extensively metabolized to CO2, a portion is excreted in the urine in acid labile "bound" forms. Since much of the MDA in the diet is apparently bound to protein, the metabolism of protein-bound MDA was investigated. MDA was reacted with serum albumin and fed to rats. A urinary metabolite was detected which was shown to be identical to a metabolite of the lysine-MDA enaminal N epsilon-(2-propenal)lysine. After isolation by ion exchange and high performance liquid chromatography the metabolite was identified using high field nuclear magnetic resonance spectroscopy and fast atom bombardment-mass spectroscopy as N alpha-acetyl-epsilon-(2-propenal)lysine. This compound also was a major urinary metabolite of the Na enol salt of MDA administered by stomach intubation, and was excreted in increased amounts by rats fed a diet containing a highly peroxidizable oil (cod liver oil). It was also detected in the urine of fasted animals after injection with NaMDA, indicating that it is formed as a product of lipid peroxidation in vivo as well as of peroxidation of dietary lipids.
Animals↗
High-resolution (13)C nuclear magnetic resonance spectroscopy pattern recognition of fish oil capsules.
13C NMR (nuclear magnetic resonance) spectroscopy, in conjunction with multivariate analysis of commercial fish oil-related health food products, have been used to provide discrimination concerning the nature, composition, refinement, and/or adulteration or authentication of the products. Supervised (probabilistic neural networks, PNN) and unsupervised (principal component analysis, PCA; Kohonen neural networks; generative topographic mapping, GTM) pattern recognition techniques were used to visualize and classify samples. Simple PCA score plots demonstrated excellent, but not totally unambiguous, class distinctions, whereas Kohonen and GTM visualization provided better results. Quantitative class predictions with accuracies >95% were achieved with PNN analysis. Trout, salmon, and cod oils were completely and correctly classified. Samples reported to be salmon oils and cod liver oils did not cluster with true salmon and cod liver oil samples, indicating mislabeling or adulteration.
Animals↗
Effect of added lipids on the texture of minced hake (Merluccius merluccius L.), megrim (Lepidorhombus whiffiagonis W.) and sardine (Sardina pilchardus W.) during frozen storage.
The effect of added cod liver oil and oxidized cod liver oil on the measurement of texture in minced hake (Merluccius merluccius L.), megrim (Lepidorhombus whiffiagonis W.) and sardine (Sardina pilchardus W.) has been measured during frozen storage (-18 degrees C). The results show that added neutral and oxidized lipids, even at high rancidity levels, do not affect shear resistances measured by the Kramer shear-compression cell in non-formaldehyde forming species such as megrim and sardine, over the frozen storage period. However, in a formaldehyde-forming species such as hake, in the presence of neutral and oxidized lipids at the end of the storage period, the values of shear resistances may be lower than in the absence of these lipids, probably owing to formation of less formaldehyde in these cases. Although it is very difficult to estimate the importance of a single compound or group of compounds on texture, these results seem to indicate that formaldehyde is a much more important factor than oxidized lipids in changes of texture in fish.
Analysis of Variance↗
Effects of n-3 polyunsaturated fatty acids on coronary heart disease.
The purpose of this paper is to discuss the role of n-6 and n-3 polyunsaturated fatty acids in coronary heart disease (CHD). The level of n-6 and n-3 fatty acids in plasma and cardiac phospholipids was examined in relation to CHD in man. The fatty acid profile of cardiac phospholipids was also examined in relation to various risk factors of CHD, such as the composition of dietary fat, aging and stress. Life expectancy in Iceland is higher than in other Nordic countries, and the cardiovascular diseases mortality is lower in Iceland in the older age groups. There is a positive correlation between the level of arachidonic acid (AA) in plasma phospholipids (PL) in the normal population and cardiovascular disease mortality in Nordic countries. The level of AA in plasma PL is significantly higher in patients with CHD than in normal subjects. Dietary intake of fish or fish oil lowers cellular levels of AA and favorably influences eicosanoid metabolism in platelets and leukocytes. The roles of n-6 and n-3 fatty acids in heart muscle are less well understood. Rats fed diets containing either 10% butter, corn oil or cod liver oil showed markedly different fatty acid composition of individual phospholipids in sarcolemma. Dietary cod liver oil lowered the AA level in sarcolemmal phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) by 50% compared to butter or corn oil fed rats, replacing AA with docosahexaenoic acid (DHA). Adaptation to moderate to severe stress induced by repeated administration of catecholamines for 15 days resulted in marked but reversible alterations in the fatty acid profile of cardiac phospholipids. During severe stress the level of AA increased by 50% in PC replacing linoleic acid (LA), whereas in PE the DHA increased markedly replacing LA. Aging was accompanied by similar alterations in cardiac phospholipids, increased levels of AA in PC and increased DHA in PE. The incidence of ventricular fibrillation (VF) and sudden cardiac death induced by isoproterenol in adult rats fed different dietary fat was lowest in rats fed cod liver oil, with a low ratio of AA/DHA in cardiac phospholipids. Mortality due to VF was highest in rats fed corn oil with the highest ratio of AA/DHA. Sudden cardiac death in man was frequently associated with a higher ratio of AA/DHA than observed in people of the same age who died in accidents. The balance between n-6 and n-3 fatty acids in cellular phospholipids seems to play an important role in stress tolerance and survival.
Animals↗