Influence Of Dietary Fish Oil Research Articles

Effect of dietary fish oil sparing with blended vegetable oils on growth, fatty acid composition and lipid-metabolism-related genes expression in juvenile rainbow trout (Oncorhynchus mykiss)

Abstract A nutritional study was conducted to evaluate the influence of dietary fish oil (FO) sparing by using a mixture of vegetal oils (VO) on rainbow trout (Oncorhynchus mykiss) juveniles (30.0 g). A basal diet was supplemented with the experimental oils at a 10% level, including FO (FO diet), a blend of VO (sunflower, soybean and rapeseed oils with a 1:1:1 ratio), and a mixture (1:1 ratio) of FO and the blends of VO (MIX). In a raceway system, 450 fish were stocked in nine rectangular concrete tanks (50 fish/ tank−1). Three experimental diets, with three replicates each, were offered to fish up to visual satiation for eight weeks. Growth performance did not change among groups (P>0.05). The highest and lowest proportions of n-3 polyunsaturated fatty acids (PUFA), n-3 long chain-PUFA, especially docosahexaenoic acid, and n-3/n-6 PUFA ratio were in the whole body of FO and the VO groups, respectively (P<0.05). Serum catalase and glutathione peroxidase activities in VO group were higher than others. Serum superoxide dismutase activity in fish fed FO and VO diets was higher than MIX group (P<0.05). VO group had higher serum lysozyme, alternative complement pathway, and total immunoglobulin levels than other experimental groups. MIX group had highest serum triglyceride, cholesterol, and low-density lipoproteins. Serum high-density lipoproteins, aspartate aminotransferase, and alanine aminotransferase levels in VO treatment were in the lowest level compared to others (P<0.05). The highest relative transcription levels of fatty acid synthase, delta-6 fatty acyl desaturase, and apolipoprotein b-100 genes were in the liver of fish fed the MIX diet. The relative transcription level of the fatty acid-binding protein1 gene did not change (P>0.05). In summary, the results of this study revealed that dietary FO sparing with VO did not adversely affect the growth and health indices of rainbow trout; nevertheless, it had adverse effects on its nutritional values by reducing whole-body n-3 LC-PUFA content.

The influence of dietary fish oil on platelet composition in cardiac patients

Background and Aims: The habitual ingestion of fish is assumed to lower the incidence of coronary heart disease. Death from cardiovascular disease used to be rare among Inuits. It is suggested that C20:5 in the platelets is converted by the vascular-wall tissue to an anti-aggregatory prostacyclin. Partial dietary substitution of arachidonic acid by eicosapentaenoic acid may reduce the incidence of thrombotic disorders, including myocardial infarction. Recently high N-3 level fish oils in natural triglyceride form (20% docosahexanoic acid and 30% eicosapentanoic acid) were introduced.

Dietary fatty acid profiling in plant protein‐rich diets affects the reproductive performance, egg fatty acid profile and haematological parameters in female rainbow trout ( Oncorhynchus mykiss )

The influence of dietary fish oil (FO) substitution with blends of vegetal oils (VO: canola, linseed, olive, sunflower, corn and coconut oils) in plant protein‐rich diets on reproductive performance and fatty acid dynamics of embryos was evaluated in female rainbow trout (Oncorhynchus mykiss) brooders (1.8 ± 0.1 kg). Four diets were formulated in which 20% (FO₈₀/VO₂₀), 50% (FO₅₀/VO₅₀), 75% (FO₂₅/VO₇₅) and 100% (VO₁₀₀) of FO were replaced by mixture of VO. The above‐mentioned diets were administered for a short period prior to spawning (3 months). Fish fed the VO₁₀₀ had the lowest fertilization rate (81.3 ± 2.3), whereas brooders fed the FO₈₀/VO₂₀ diet had the lowest survival rates at eyed embryo stage (83.7 ± 1.6%) and hatching rate (79.9 ± 3.1%). The fatty acid dynamics of embryos were not only affected by embryonic developmental stages, but also they were influenced by the dietary fatty acid profile. Our study confirmed that using blends of different VO sources and FM residual fat in the FO₂₅/VO₇₅ for the short‐term period prior to spawning seemed to be a good strategy in terms of successful reproduction for sparing high levels of FM and FO in diet of O. mykiss brooders.

The influence of dietary fish oil and vitamin E on the fatty acid profile and oxidative stability of frozen stored chicken breast meat

oC) and stored for 6 months. Samples were analysed for fatty acid composition, thiobarbituric acid reactive substances (TBA-RS), and α-tocopherol content. Fish oil positively affected the performance of chickens, elevated the content of stearic (C 18:0 ) and eicosapentaenoic (C 20:5,n-3 ) acids, and lowered the polyunsaturated fatty acid (PUFA) n-6:n-3 ratio in stored breast meat. Fish oil at 8 g · kg -1 in the diet decreased linolenic acid (C 18:3, n-3 ), unsaturated fatty acid, and n-6 PUFA contents, increased saturated fatty acid (SFA) content in lipids and lowered the PUFA:SFA ratio. The addition of 150 or 300 mg · kg -1 α-tocopheryl acetate to the diets increased the level of vitamin E in stored breast meat and lowered the TBA-RS value. The levels of fish oil and vitamin E used had no effect on the sensory properties of meat.

Influence of dietary fish oil on conjugated linoleic acid, omega-3 and other fatty acids in milk fat from grazing dairy cows

The main objective of this study was to evaluate the effect of supplementation with fish oil on fatty acid (FA) composition of milk fat from grazing dairy cows with particular emphasis on omega-3 and conjugated linoleic acid. Twelve dairy cows in mid-lactation were blocked by live weight, days in lactation and milk production and randomly assigned to the experimental groups corresponding to 3 different feeding regimens which were applied 3 times with 28-day duration according to a Latin square design. Cows were stocked at 2.5 heads per hectare and supplemented with 4 kg concentrate/cow/day (C), concentrate mixed with 160 g sardine oil (LFO) and concentrate mixed with 320 g sardine oil (HFO). Supplementation with fish oil (FO) resulted in a significant ( P<0.05) decrease in milk production and milk fat content and production. Supplementation with 320 g FO decreased ( P<0.05) milk protein content and production. The ratio protein/fat in milk increased with the level of FO supplemented ( P<0.05). Significant correlations were detected between some FA in milk fat and milk fat content. FO supplementation had no effect on concentration of medium chain FA but originated a decrease ( P<0.05) in concentration of short and long chain FA in milk fat. The sum of saturated FA decreased ( P<0.05) with the inclusion of FO in diet while the sum of unsaturated FA remains unchanged. Proportions of stearic and oleic FA in milk fat decreased and trans-vaccenic FA increase with FO supplementation ( P<0.05). Milk fat concentration of polyunsaturated n-3 FA was higher in treatment HFO. Concentration of very long chain omega FA in milk fat (i.e. C20:5-EPA e C22:6-DHA) increased by 2.7-fold with 160 g FO and by 5- to 7-fold with 320 g FO. However, the level of transfer efficiency of these FA from FO to milk fat was only 3.3% in treatment LFO and 4.0% in treatment HFO. CLA concentrations in milk fat were particularly high in this experiment and increased with the level of FO supplementation ( P<0.05).

The influence of dietary fish oil vs. sunflower oil on the fatty acid composition of plasma cholesteryl-esters in healthy, adult cats.

The question addressed was whether the fatty acid composition of plasma cholesteryl esters (CEs) in cats reflects the intake of fatty acids. Diets containing either fish oil or sunflower oil were fed to six healthy, adult cats in a cross-over trial. The dry cat foods contained approximately 18.5% crude fat, of which two-third was in the form of the variable oil. Blood samples were collected at the end of each 4-week feeding period, and the fatty acid composition of plasma CEs and plasma concentrations of lipoproteins were determined. Consumption of the diet with fish oil was associated with significantly greater proportions of eicosapentaenoic acid, arachidonic acid, alpha-linolenic acid, oleic acid, palmitic acid and myristic acid in plasma CEs. The intake of fish oil instead of sunflower oil reduced the percentage of linoleic acid in CEs. The plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, phospholipids and triglycerides were not affected by fish oil vs. sunflower oil feeding.

Dietary fish oil and vitamin E enhance doxorubicin effects in P388 tumor-bearing mice.

In this study, four kinds of rodent diets, CO, FO, CVe, and FVe, were used by addition of canola oil, oil mixture (fish oil + canola oil), canola oil plus vitamin E, and oil mixture plus vitamin E, respectively, to a basic diet, AIN-93G, to investigate the influence of dietary fish oil and vitamin E on doxorubicin (DOX) treatment in P388 ascitic mice. Animal life span (LS) and heart damage were recorded in mice fed the four different diets and treated with different doses of DOX. The optimal doses of DOX for antitumor effect as manifested by increased LS were 6.0 and 9.0 mg/kg. Both fish oil and vitamin E significantly enhanced this effect. On the other hand, DOX at 12.0 mg/kg induced severe heart damage, which was also significantly aggravated by both fish oil and vitamin E, as shown by both decreased LS and increased serum creatine phosphokinase activity. Fish oil and vitamin E appeared to enhance the antitumor effect of optimal doses of DOX but to aggravate cardiotoxicity owing to DOX overdose.

Influence of Dietary Fish Oil on Conjugated Linoleic Acid and Other Fatty Acids in Milk Fat from Lactating Dairy Cows

Lactating cows were fed menhaden fish oil to elevate concentrations of conjugated linoleic acid, transvaccenic acid, and n-3 fatty acids in milk. Twelve multiparous Holstein cows at 48±11 DIM were assigned randomly to a replicated 4 × 4 Latin square. Each treatment period was 35 d in length, with data collected d 15 to 35 of each period. On a dry matter (DM) basis, diets contained 25% corn silage, 25% alfalfa hay, and 50% of the respective concentrate mix. Fish oil was supplemented at 0, 1, 2, and 3% of ration DM. Linear decreases were observed for DM intake (28.8, 28.5, 23.4, and 20.4kg/d) and milk fat (2.99, 2.79, 2.37, and 2.30%) for 0 to 3% dietary fish oil, respectively. Milk yield (31.7, 34.2, 32.3, and 27.4kg/d) increased as dietary fish oil increased from 0 to 1% but decreased linearly from 1 to 3% dietary fish oil. Milk protein percentages (3.17, 3.19, 3.21, and 3.17) were similar for all treatments. When the 2% fish oil diet was fed, concentrations of conjugated linoleic acid and transvaccenic acid in milk fat increased to 356% (to 2.2g/100g of total fatty acids) and 502% (to 6.1g/100g), respectively, of amounts when 0% fish oil was fed. There were no additional increases in these fatty acids when cows were fed 3% fish oil. The n-3 fatty acids increased from a trace to over 1g/100g of milk fatty acids, when the 3% fish oil diet was fed. Fish oil supplementation to diets of dairy cows increased the conjugated linoleic acid, transvaccenic acid, and n-3 fatty acids in milk.

Dietary fish oil. Influence on lesion regression in the porcine model of atherosclerosis.

We examined the influence of dietary fish oil on lesion regression in a porcine model of atherogenesis. Thirty-two female Yucatan miniature pigs were fed an atherogenic diet for 8 months. A no-regression group (n = 8) was killed to determine the extent of atherosclerosis at 8 months. Three regression groups were switched to normal minipig chow supplemented with either MaxEPA fish oil (FO group, n = 8), a control oil with the ratio of polyunsaturated to monounsaturated to saturated fatty acid matched to that of the fish oil (CO group, n = 8), or no oil supplement (NO group, n = 8) for a further 4 months. Plasma cholesterol levels reached between 15 and 20 mmol/L during the atherogenic phase and returned to normal (2 mmol/L) within 2 months of the beginning of the regression diet. Compared with the NO group, fish oil supplementation during the regression phase caused a decrease in VLDL and HDL cholesterol and an increase in LDL cholesterol. Similarly, the control oil also caused a decrease in VLDL cholesterol; however, in contrast to the FO group, HDL cholesterol increased and LDL cholesterol was unchanged. FO LDL, which had decreased levels of 20:4 (n-6 fatty acid) and increased levels of 18:3, 20:5, and 22:6 (n-3 fatty acids), was shown to be twice as susceptible to copper-mediated oxidation as CO LDL particles. Morphological examination of the major blood vessels revealed a significant reduction in lesion area in the ascending and thoracic aorta as well as the carotid artery after the regression diet; however, there was no significant difference between the fish oil and control oil groups in any of the vessels measured. Therefore, despite increased LDL, decreased HDL, and an increased susceptibility to in vitro oxidation of LDL, fish oil supplementation of a regression diet did not influence lesion regression.

Influence of dietary fish oil on muscle metabolism during endotoxemia

Influence of dietary fish oil on muscle metabolism during endotoxemia

Influence of dietary fish oil on mitochondrial function and response to ischemia.

Dietary supplementation with marine oils may reduce the incidence of thromboembolism and decrease cardiac arrhythmias during myocardial ischemia. However, function of subcellular organelles isolated from hearts of these animals is impaired. In contrast to studies where marine oil was the sole source of dietary lipid in rats, menhaden oil was used to supplement standard canine laboratory chow. In mitochondria isolated from hearts of dogs fed this diet for 60 wk, the phospholipid content of arachidonic acid was replaced by the n-3 fatty acids, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Mitochondrial levels of linoleic and linolenic acids were not altered. The mitochondrial membrane phospholipid from the menhaden oil-fed dogs demonstrated increased cardiolipin. The respiratory function of heart mitochondria from the menhaden oil-supplemented dogs was not decreased from that of dogs on standard chow only. Increased succinate-supported respiration paralleled increased cytochrome oxidase in mitochondria from menhaden oil-fed dogs. The activity of the cardiolipin-dependent carnitine acylcarnitine translocase was unaffected. Myocardial ischemia decreased mitochondrial respiration in menhaden-fed dogs. Decreased palmitoylcarnitine-carnitine exchange following ischemia resulted from decreased matrix carnitine rather than decreased translocase activity. Normal levels of the essential fatty acids in the n-3-enriched mitochondrial membrane phospholipids appear to eliminate the mitochondrial dysfunction observed in essential fatty acid-deficient membranes.

Dietary fish oil interferes with renal arachidonic acid metabolism in rats: Correlations with renal physiology

Dietary fish oil has been reported to have both beneficial and deleterious effects in animal models of renal disease, which may be related to alterations in renal eicosanoid metabolism. The influence of dietary fish oil on glomerular and renal tubular responses that are linked to arachidonic acid metabolism was examined. Dietary fish oil had antidiuretic and antinatriuretic effects, which correlated with reduced renal cortical endogenous prostaglandin E 2 (PGE 2). Fish oil altered the renal balance of dienoic prostacyclin (PGI 2) to thromboxane (TXA 2) in favor of vasodilation, which may explain the observed exaggerated compensatory increases in glomerular function in response to uninephrectomy. Intact rats fed fish oil for 6 months developed proteinuria and impaired glomerular filtration rates (GFR). These deleterious effects were associated with evidence of increased renal lipid peroxidation. These results suggest that dietary fish oil modifies glomerular and renal tubular function in rats, and worsens age-associated proteinuria and declines in GFR. These effects may reflect the impact of dietary fish oil on renal fatty acid composition and arachidonic acid metabolism.

Influence of Dietary Fish Oil on Granulomatous Inflammation in the Lung Following Inhalation of Silica and Infection with Bacillus Calmelte-Guerin

AbstractRecent evidence has suggested that fish oil diets, in addition to purported beneficial effects on the cardiovascular system, may also act to modulate inflammatory and immunologic reactions. These actions may be due to an increased content in fish oils of the n-3 fatty acid, eicosapentaenoic acid, which can competitively inhibit the production of arachidonic acid metabolites, forming 3-series prostaglandins and 5-series leukotrienes. In many cases these metabolites are not as biologically active as those formed from arachidonic acid. We examined the effects of dietary fish oil on granu-lomatous lesion development, pulmonary adherent cell (macrophage) activity, and arachidonic acid metabolite production following a regimen of silica inhalation and infection with Bacillus Calmette-Guerin (BCG). Mice on diets containing 10% corn oil or a mixture of 9% fish and 1% corn oils were placed in silica inhalation chambers for 6 wk, infected with BCG, and returned to inhalation chambers. Control animals, on ei...

Influence of Dietary Fish Oil on the Aortic, Myocardial, and Renal Lesions of SHR.

To examine the effects of menhaden oil on the progressive glomerulosclerosis, arteriosclerosis, plasma cholesterol and triglyceride levels, and myocardial damage, spontaneously hypertensive rats (SHR) were fed Purina rat chow supplemented either with 6 g % of menhaden oil or with 6 g % of corn oil. They were sacrificed on the 12th and 18th months, and the kidneys, aorta, and heart were examined by light microscopy. At sacrifice, body weight, plasma creatinine, systolic blood pressure, 24 h' urinary protein output, total plasma cholesterol and triglyceride, glomerular filtration rate (GFR), and glomerulosclerosis index were measured. There was no significant difference between the experimental and control groups in the average body weight, plasma creatinine level, systolic blood pressure, total 24 h urinary protein output, and glomerular filtration rate. Rats with menhaden oil had, however, statistically significant less aortic arteriosclerosis, myocardial damage, plasma cholesterol and triglyceride levels, and renal interstitial fibrosis than those with corn oil. The glomerular damage of the former as expressed by glomerulosclerosis index was numerically less than that of the latter. The data indicated that menhaden oil lessened the hypertensive damage to the renal and cardiovascular systems.

Influence of dietary fish oil on the relative synthesis of triacylglycerol and phospholipids in rat liverin vivo

The influence of dietary fish oil containing n-3 polyunsaturated fatty acids on the biosynthesis of triacylglycerol relative to total individual phospholipids was studied in rat liver in vivo. The dietary lipid (10% by weight of diet) was either sunflower oil enriched in linoleic acid (SO group) or MaxEPA fish oil/sunflower oil, 9:1 by weight (FO group) enriched in eicosapentaenoic acid (EPA, 20:5n-3) plus docosahexaenoic acid (DHA, 22:6n-3). After a 3-week feeding period, the triacylglycerol content (in mumol/g liver) was 44% lower in the FO group relative to the SO animals. The in vivo incorporation of [3H]glycerol into individual hepatic lipids resulted in triacylglycerol/total phospholipid radioactivity ratios of 2.1 and 0.9 for the SO and FO groups, respectively. These results indicate an inhibitory effect of dietary EPA/DHA on triacylglycerol relative to phospholipid synthesis from intermediary 1,2-diacylglycerol in rat liver in vivo. This metabolic alteration was accompanied by a substantially lower amount (in mumol/g liver) of arachidonic acid and higher levels of EPA plus DHA in the triacylglycerol, choline glycerophospholipid (CGP), and ethanolamine glycerophospholipid (EGP) of the FO group. A moderately higher labelling of the EGP from [3H]glycerol was observed in the FO as compared to the SO group (as evidenced by CGP/EGP radioactivity ratios of 1.3:1 and 1.8:1, respectively). The present study provides in vivo evidence for a dampening effect of dietary fish oil on the synthesis of liver triacylglycerol relative to phospholipid and a moderate alteration of de novo synthesis of individual phospholipids.

Influence of dietary fish oil on arterial thrombosis and atherosclerosis in animal models and in man

In animal models of arterial thrombosis, fish-oil-enriched diets have been shown to have an antithrombotic effect. There is strong evidence, however, that this only holds if the fish-oil consumption is associated with a reduction of the saturated fat intake. In animal models of atherosclerosis the effect of a marine diet is not consistent. Although in some studies with cod-liver oil (which is relatively low in saturated fatty acids) a beneficial effect is observed, studies with other, more saturated fish oils do not confirm this. The influence of fish-oil consumption on some thrombotic complications of human atherosclerosis is not well documented. So far, the few results reported are not very promising, but it should remembered that this mainly concerns short-term studies. Studies with respect to human fibrinolysis are equivocal. Evidence has been obtained that fish consumption may even have an adverse effect on certain aspects of the fibrinolytic process. The studies performed so far do not provide conclusive evidence as to the importance of fish- and fish-oil-enriched food for prevention and therapy of ischaemic cardiovascular disease. Further research is needed, especially with long-term, high-quality animal models. Moreover, long-term, well-controlled, prospective human intervention studies are required to investigate the effect of feasible fish(oil)-enriched diets on morbidity and mortality of ischaemic cardiac and vascular diseases.