Showing papers on "Fish oil published in 1991"
Journal Article•
TL;DR: Results suggest that EPA as the pure fatty acid should be considered for clinical investigation as both an anticachectic and antitumor agent, since prior work has shown that the other major component of fish oil docosahexaenoic acid is without pharmacological activity in this system.
Abstract: The effect of the polyunsaturated fatty acids eicosapentaenoic acid (EPA) and gamma-linolenic acid (GLA) on host body weight loss and tumor growth has been investigated in mice bearing a cachexia-inducing colon adenocarcinoma, the MAC16. EPA effectively inhibited both host weight loss and tumor growth rate in a dose-related manner with optimal effects being observed at a dose level of 1.25 to 2.5 g/kg. At these concentrations host body weight was effectively maintained, and there was a delay in the progression of growth of the tumor, such that overall survival was approximately doubled in EPA-treated animals, using the criteria dictated by the United Kingdom Coordinating Committee for the welfare of animals with neoplasms. Even when tumor growth resumed, weight loss did not occur. Animals bearing the MAC16 tumor showed a decreased protein synthesis and an increased degradation in skeletal muscle. Treatment with EPA significantly reduced protein degradation without an effect on protein synthesis. The effect of GLA on both host body weight loss and tumor growth was much less pronounced than that of EPA, with an effect only being seen at a dose of 5 g/kg, at which some toxicity was observed. In vitro studies showed that while EPA was effective in inhibiting tumor-induced lipolysis, GLA was ineffective in this respect. However, prostaglandin E1, which is formed from GLA in vivo, showed partial reversal of tumor-induced lipolysis and probably accounted for the anticachectic effect of GLA. These results suggest that EPA as the pure fatty acid should be considered for clinical investigation as both an anticachectic and antitumor agent, since prior work has shown that the other major component of fish oil docosahexaenoic acid is without pharmacological activity in this system.
235 citations
TL;DR: Although long-term fish oil supplementation may be beneficial in reducing plasma total TG, susceptibility of plasma lipids to free radical attack is potentiated.
Abstract: Fifteen young (22-35 y) and 10 older (51-71 y) women received six capsules of fish oil (Pro-Mega)/d, providing a total of 1,680 mg eicosapentaenoic (EPA), 720 mg docosahexaenoic (DHA), 600 mg other fatty acids, and 6 IU vitamin E. Blood was collected before and after 1, 2 and 3 mo of supplementation. Compliance was confirmed by the significant increase in plasma EPA and DHA in all women. Older women had a significantly higher increase in EPA and DHA than did young women (10-fold increases in EPA and 2.5-fold increases in DHA vs. 8-fold in EPA and 2-fold in DHA for older and young women, respectively). The decrease in the arachidonic acid:EPA ratio was more dramatic in the older women. Plasma total triglycerides (TG) decreased significantly, and the ratio of polyunsaturated fatty acids to saturated fatty acids was significantly (P less than 0.01) increased. Plasma vitamin E levels did not change significantly after supplementation; however, after 3 mo of supplementation by young women, plasma vitamin E was significantly lower than after 1 mo. The vitamin E: TG ratio was significantly increased and vitamin E:(EPA + DHA) significantly decreased. All women showed a significant increase in plasma lipid peroxide through mo 2 of supplementation. After 2 mo, older women had significantly higher lipid peroxide levels than young women. The lipid peroxide:TG ratio, which declined by mo 3, was still significantly higher than baseline. These data indicate that although long-term fish oil supplementation may be beneficial in reducing plasma total TG, susceptibility of plasma lipids to free radical attack is potentiated.(ABSTRACT TRUNCATED AT 250 WORDS)
218 citations
TL;DR: It is established that a diet with a low (n-3)/(n-6) ratio can cause changes in fatty acid metabolism that are deleterious to the health of salmonid fish, especially when subjected to stress.
Abstract: For 16 wk Atlantic salmon (Salmo salar) post-smolts were fed practical-type diets that contained either fish oil (FO) or sunflower oil (SO) as the lipid component. Both diets contained adequate (n-3) polyunsaturated fatty acids (PUFA). All the phospholipids of heart and liver from SO-fed fish had increased levels of 18:2(n-6), 20:2(n-6) and 20:3(n-6); phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) also had increased 20:4(n-6). There was a general decrease in 20:5(n-3) in the phospholipids, reflected in an increase in the 20:4(n-6)/20:5(n-3) ratio, especially in PC and PE. The fatty acid compositions of phospholipids from brain and retina were much less affected by dietary linoleate than those of heart and liver. Fish fed SO developed severe heart lesions that caused thinning of the ventricular wall and muscle necrosis. The fish fed SO also were susceptible to a transportation-induced shock syndrome that caused 30% mortality. These results establish that a diet with a low (n-3)/(n-6) ratio can cause changes in fatty acid metabolism that are deleterious to the health of salmonid fish, especially when subjected to stress.
216 citations
TL;DR: This study showed that n-3 fatty acids in fish oil given as ethyl esters or triglycerides were equally well absorbed and Eicosapentaenoic and docosahexaenoic acids were also equally absorbed.
156 citations
TL;DR: The type of dietary fat can clearly affect the growth of human breast carcinomas (MCF-7 and MDA-MB231) maintained in athymic nude mice.
Abstract: Human breast carcinoma cell lines MCF-7 and MDA-MB231 were transplanted s.c. to female athymic nude mice at 3-4 weeks of age. At 7-10 days after transplantation, the mice were divided into groups and fed for 6-8 weeks one of the following semi-purified diets containing different amounts and types of fat, i.e. 5% corn oil, 20% corn oil, 20% butter, 19% beef tallow/1% corn oil and 19% fish (Menhaden) oil/1% corn oil. In addition experiments, the fish oil diets were supplemented with antioxidants (vitamin E, 8 g or 2000 IU/kg diet plus tertiary butyl hydroquinone, TBHQ, 4 g/kg diet) or ferric citrate (3 g/kg diet). Tumor peroxidation product levels were assessed by measuring 2-thiobarbituric acid reactants (TBA assay). At the termination of the studies (6-8 weeks of diet feeding) mean human breast carcinoma volume (MCF-7 and MDA-MB231) was the largest in mice fed the 20% corn oil diet, intermediate in mice fed the butter or beef tallow diets and the least in mice fed the fish oil diet. The difference in mean tumor volumes among mice fed the 20% corn oil diet and those fed the fish oil diet was significant (P less than 0.01). When comparing low (5% corn oil) and high (20% corn oil) fat diets, numerical increases in human breast carcinoma volume (MCF-7 and MDA-MB231) were consistently observed in the high-fat diet groups but these differences were not always significant. Tumor lipid peroxidation product levels were determined on the MDA-MB231 tumors; tumor lipid peroxidation levels were significantly (P less than 0.01) increased only in mice fed the fish oil diets. Supplementation of the fish oil diets with antioxidants (vitamin E + TBHQ) significantly reduced the level of tumor peroxidation products and significantly increased tumor volume (P less than 0.05). When tumor lipid peroxidation product levels in the fish oil plus antioxidant fed mice were reduced to the level of that observed in the tumors of the corn oil fed mice, no significant differences in tumor volumes were observed in these two groups. In contrast, supplementation of the fish oil diets with ferric citrate, significantly (P less than 0.05) increased tumor lipid peroxidation product levels and decreased tumor volume. Thus, the type of dietary fat can clearly affect the growth of human breast carcinomas (MCF-7 and MDA-MB231) maintained in athymic nude mice.(ABSTRACT TRUNCATED AT 400 WORDS)
154 citations
TL;DR: Investigators examining variables that are influenced by altered membrane fatty acid composition should be aware of these prolonged effects when designing studies and a parallel design becomes essential.
149 citations
TL;DR: The effect of vitamin E may be due to inhibition of fatty acid peroxidation with less formation of malondialdehyde and a larger amount of active (n-3) fatty acids in their sites of action in the liver, resulting in a greater decrease in the synthesis of triglycerides and fibrinogen.
Abstract: The effects of fish oils supplemented with 0.3 IU/g and 1.5 IU/g of vitamin E were compared in a double-blind, cross-over study. Twelve healthy volunteers were given 30 mL/day of either oil for 3 wk. Intake of the vitamin E-rich fish oil resulted in a marked decrease in serum triglycerides (48%) and in fibrinogen (11%). After administration of the low vitamin E-containing oil there was a considerably smaller reduction of serum triglycerides and no significant reduction of fibrinogen. Both oils caused an increase in high density lipoprotein cholesterol and a decrease in the atherogenic index, but neither oil altered the total cholesterol level. Serum vitamin E was decreased by 9% and plasma malondialdehyde was increased by 122% after intake of the low vitamin E-containing oil, but both remained normal after intake of the other oil. The effect of vitamin E may be due to inhibition of fatty acid peroxidation with less formation of malondialdehyde and a larger amount of active (n-3) fatty acids in their sites of action in the liver, resulting in a greater decrease in the synthesis of triglycerides and fibrinogen.
147 citations
TL;DR: The rat liver microsomal fatty acid desaturases were measured and it was found that with pellet fed rats the rates were highest for delta 9-desaturase and in decreasing order lower for delta 5-desaturation, delta 6-Desaturation with 18:3 (n-3) as substrate and finally delta 6:2(n-6) as substrates.
144 citations
TL;DR: Ingestion of fish oil resulted in a significant rise in TBARS in plasma, LDL, conditioned LDL, and metabolism of conditioned LDL by macrophages and in nonsmokers, the baseline values of the above parameters were lower than in smokers.
141 citations
TL;DR: This review highlights these and other potentially antiatherogenic properties of marine lipids in diabetic subjects and several short-term clinical trials in which fish-oil concentrates have been administered to various populations at risk for coronary heart disease, including patients with diabetes mellitus.
Abstract: Fish oils exert important biological effects on several pathways predisposing to atherosclerosis. Epidemiological studies provided the initial evidence that omega-3 fatty acids may be the principal factor in fish oils responsible for these effects and have led to several short-term clinical trials in which fish-oil concentrates have been administered to various populations at risk for coronary heart disease, including patients with diabetes mellitus. omega-3 Fatty acids reduce serum lipids and lipoproteins, impair platelet aggregation, increase cell membrane fluidity, and lower blood pressure in humans. In this review, we highlight these and other potentially antiatherogenic properties of marine lipids in diabetic subjects.
139 citations
TL;DR: The data suggest that free radical stress occurs during BDL in the rat and may result in mitochondrial lipid peroxidation, and that diets high in lipid may increase free radical damage to hepatic mitochondria.
TL;DR: Several digestion and absorption specific steps are worth studying with reference to the crucial role of polyunsaturated fatty acids in the organism, and for example adaptation of possible dietary supplements.
Abstract: Polyunsaturated fatty acids play an important part in the structure and function of cellular membranes and are precursors of lipid mediators which play a key role in cardiovascular and inflammatory diseases. Dietary sources of essential fatty acids are vegetable oils for either linoleic or alpha-linolenic acids, and sea fish oils for eicosapentaenoic and docosahexaenoic acids. Because of the specificity of the pancreatic lipid hydrolases, triglyceride fatty acid distribution is an essential parameter in the digestibility of fats. The efficiency of the intestinal uptake depends on the hydrolysis and especially on their micellarization. n-3 polyunsaturated fatty acid ethyl ester digestion is recognized to be impaired, but n-3 polyunsaturated fatty acid triglyceride hydrolysis remains a controversial point, and to some authors explains differences observed between vegetable and fish oil absorption. So additional studies are required to investigate this intestinal step. In enterocytes, morphological and biochemical absorption processes involve reesterification of long-chain fatty acids and lipoprotein formation. At this level, specific affinity of I- and L-FABPc (cytosolic fatty acid binding proteins) to polyunsaturated fatty acids requires further investigation. A better understanding of the role of these FABPc might bring to light the esterification step, particularly the integration of polyunsaturated fatty acids into phospholipids. With reference to differences published between fish and vegetable oil absorption, longer-term absorption studies appear essential to some authors. Polyunsaturated fatty acid absorption is thought to be not very dissimilar to that of long-chain mono-unsaturated fatty acid absorption. However, several digestion and absorption specific steps are worth studying with reference to the crucial role of polyunsaturated fatty acids in the organism, and for example adaptation of possible dietary supplements.
TL;DR: It is concluded that colonic lipids and prostaglandin and thromboxane synthesis can be readily altered by dietary supplementation with fish oil.
Abstract: The incorporation of the fatty acids in fish and olive oil into the colonic mucosa of patients with inflammatory bowel disease was examined during 12 weeks' dietary supplementation with the oils, and the influence on colonic mucosal prostaglandin and thromboxane generation was measured. With a dietary supplement of 18 g fish oil daily, concentrations of the major polyunsaturated fatty acids in fish oil, eicosapentaenoic acid and docosahexaenoic acid, were significantly raised in mucosal lipids. The first time these were measured, after three weeks' supplementation, the mean increases in eicosapentaenoic and docosahexaenoic acid were seven fold and 1.5 fold respectively, and these increases were maintained during the 12 week study. Arachidonic acid values fell throughout the study and this reduction was significant at 12 weeks. Mucosal prostaglandin E2 (PGE2), thromboxane B2, and 6-keto prostaglandin F1 alpha synthesis were suppressed, and this reached significance (p less than 0.05) at three and 12 weeks for PGE2 and at 12 weeks for thromboxane B2. The predominant fatty acid in olive oil is oleic acid. Supplementation with 18 g/day resulted in a significant increase in oleic acid in colonic mucosa at 12 weeks (p less than 0.05) and a fall in stearic acid and docosahexaenoic acid; there was no significant change in eicosanoid synthesis. It is concluded that colonic lipids and prostaglandin and thromboxane synthesis can be readily altered by dietary supplementation with fish oil. The extent of incorporation of the fatty acids present in oils is dependent upon the individual fatty acid.
TL;DR: A measure of the overall potential of dietary oils to exert local anti-inflammatory effect was evolved, for example, the leukotriene inhibition potentials of both fish oil and borage oil were greatly enhanced when compared to controls.
TL;DR: Dietary fish oil might suppress triglyceride secretion by decreasing glycerolipid synthesis, an effect mediated by changes in one or more enzymes involved in phosphatidate catabolism.
Abstract: Studies were conducted to explore the mechanisms by which dietary fish oil decreases hepatic triglyceride secretion. Forty-five rats (15/group) were fed purified diets containing 10% fat as either fish oil, safflower oil or palm oil for 10 d. Plasma triglyceride concentration was lowest in the fish oil-fed group followed by the groups fed safflower oil and palm oil. The liver's capacity to oxidize fatty acids was assessed by assays of mitochondrial and peroxisomal beta-oxidation pathways in whole homogenates. Additionally, key enzymatic activities in the biosynthesis of triglyceride (diacylglycerol acyltransferase, phosphatidate hydrolysis) and phosphatidylcholine (CTP:phosphocholine cytidylyltransferase) were assayed. Compared with those fed palm oil the fish oil-fed animals showed 25% greater mitochondrial beta-oxidation but this difference was not statistically significant (P = 0.1). Fish oil feeding led to 45% greater (P less than 0.05) peroxisomal beta-oxidation. Diacylglycerol acyltransferase activity was unaffected by the type of dietary fat and slightly (13%) but significantly (P less than 0.02) lower cytidylyltransferase activity due to fish oil feeding was observed. More strikingly, both fish oil and safflower oil diets significantly lowered phosphatidate hydrolysis by 37 and 22%, respectively, compared with the palm oil diet. This activity directly correlated (r = 0.68; P less than 0.001) with plasma triglyceride concentration. Thus, dietary fish oil might suppress triglyceride secretion by decreasing glycerolipid synthesis, an effect mediated by changes in one or more enzymes involved in phosphatidate catabolism.
TL;DR: The studies indicate that the incorporation of EPA in the diet as a substitute metabolic pathway could be a unique way of correcting the biochemical abnormalities of idiopathic urolithiasis.
TL;DR: It is suggested that the constitutive P450 enzyme level is regulated by dietary fat/carbohydrate ratios, and both the quantity and the extent of unsaturation of dietary lipids affected P450IIE1 regulation.
Abstract: The present work tests the hypothesis that high fat/low carbohydrate diets elevate the level of liver microsomal cytochrome P450IIE1. Male Sprague-Dawley rats were fed liquid diets containing varied ratios of corn oil/carbohydrate for 4 d. Rats fed diets with higher fat/carbohydrate ratios produced higher serum acetone levels and higher hepatic microsomal P450IIE1 content and N-nitrosodimethylamine demethylase activity than those fed diets with lower fat/carbohydrate ratios. This dietary fat/carbohydrate effect on P450IIE1 also was observed with modified semipurified AIN-76A diets. In addition, both the quantity and the extent of unsaturation of dietary lipids affected P450IIE1 regulation. At moderate fat levels (5 and 20% diet), rats fed corn oil and menhaden oil diets produced higher P450IIE1 activity than those fed lard and olive oil diets. Rats fed a diet containing 20% corn oil or an amount of linoleic acid equivalent to the 20% corn oil diet showed twofold to threefold increases in the level of P450IIE1 over those fed a fat-free diet. Rats fed a 25% corn oil diet showed twofold higher enflurane metabolism in vivo than those fed a 0.5% corn oil diet. The present results suggest that the constitutive P450 enzyme level is regulated by dietary fat/carbohydrate ratios.
TL;DR: Because whole-blood viscosity consistently fell, probably due to an increased erythrocyte deformability, the observed changes in lipid metabolism and blood rheology may also help reduce cardiovascular risk factors in subjects with IGT.
Abstract: To determine the impact of fish-oil supplementation on glucose and lipid metabolism in patients with impaired glucose tolerance (IGT), 30 ml fish oil containing 3.8 g eicosapentaenoic acid (EPA; 20:5 ω 3) and 2.5 g docosahexaenoic acid (DHA; 22:5 ω 3) were given to eight obese subjects with IGT (mean ± SD age 50.3 ± 8.0 yr) in addition to their regular diet for 2 wk. Studies were performed in randomized order versus an isocaloric control period with a washout phase of 3 wk. Hyperinsulinemic clamp examinations (1 and 10 mU · kg −1 · min −1 ) were performed. Glucose disposal rate (M value) rose from basal 14.3 ± 5.1 to 17.9 ± 4.4 μmol · kg −1 · min −1 after fish oil ( P −1 · min −1 ; with fish oil, 45.1 ± 9.8 μmol · kg −1 · min −1 ;NS). Basal hepatic glucose output remained unaffected by fish oil, whereas fractional glucose clearance after intravenous glucose loading (2.4 mmol/kg body wt, t = 30 min) tended to increase ( K value: without fish oil, 2.15 ± 1.02%/min; with fish oil, 2.74 ± 1.26%/min; NS). Neither the fasting concentrations of glucose and insulin nor induced glycemia and insulin response during intravenous glucose loading calculated as incremental area under the curve changed after fish-oil supplementation. Supplementation of ω-3 fatty acids led to a mean decrease in total cholesterol of 15.2% (5.78 ± 1.19 to 4.90 ± 0.83 mM, P P P P
TL;DR: It is shown that a dietary supplement of fish oil decreases plasma triglyceride levels in non-insulin-dependent diabetic patients, an increased conversion rate of VLDL to LDL playing a role in this change.
TL;DR: Eating fatty fish and fish oil produced comparable lipid and lipoprotein changes, but only the fish improved hemostatic factors.
TL;DR: The results indicate that the ratio of n-3 to n-6 fatty acids in the diets, rather than the absolute amount ofn-3 fatty acids, is the determining factor in inhibiting eicosanoid biosynthesis from AA.
TL;DR: The dietary supplement of pure E-EPA was more effective in limiting platelet reactivity than a concentrated fish oil extract providing an equivalent amount of omega-3 fatty acids.
TL;DR: Findings indicate that n-3 PUFA are differentially incorporated into macrophage phospholipid subclasses after dietary fish oil supplementation, and suggest that phospholIPid remodeling enzymes selectively discriminate between substrates based on compatibility of sn-1 covalent linkage and the composition of thesn-1 and sn-2 aliphatic chains.
TL;DR: It is suggested that oxidation of fatty acids can occur until a critically low level of intact phospholipid in the RBC membrane is reached, after which the membrane destabilizes and hemolysis occurs, and the increased n-3 PUFA content of +FO RBCs serves as an oxidizable buffer.
TL;DR: Low doses of fish oil may have a mild immunosuppressive effect affecting both T and B cell functions, and the need for more extensive trials designed to determine whether immunOSuppressive effects can be consistently elicited is stressed.
TL;DR: The incorporation of fatty acids from dietary fish oil was measured in obstructive atherosclerotic plaques removed from 11 patients fed fish oil, rich in omega-3 fatty acids, for 6-120 days before a planned arterial endarterectomy to find out whether changes in fatty acid composition led to a higher unsaturation index in the fish oil-fed group.
Abstract: The incorporation of fatty acids from dietary fish oil was measured in obstructive atherosclerotic plaques removed from 11 patients fed fish oil, rich in omega-3 fatty acids, for 6-120 days before a planned arterial endarterectomy. The fatty acids of plasma and atheroma were analyzed with special reference to docosahexaenoic acid (DHA, 22:6) and eicosapentaenoic acid (EPA, 20:5), the principal omega-3 fatty acids of fish oil. The omega-3 fatty acid content increased greatly in plasma from 0.9% of fatty acids to 14.8% in cholesteryl esters, from 3.8% to 22.1% in phospholipids, and from 1.3% to 21.9% in triglycerides. The omega-3 fatty acid content of the atherosclerotic plaques was also greater when compared with that of plaques removed from 18 non-fish oil-fed controls. The omega-3 fatty acid in cholesteryl esters of the plaques was 4.9% in the experimental group versus 1.4% in control plaque, in phospholipids it was 8.8% versus 1.8%, and in triglycerides it was 4.7% versus 0.7% (p less than 0.001 for each lipid class). The two major omega-3 fatty acids (DHA and EPA) behaved differently. Compared with their respective plasma levels, relatively more DHA than EPA was deposited into the plaques. Whereas the increase of omega-3 fatty acids in plasma reached a plateau 3 weeks after initiation of fish oil feeding, a linear increase in plaque omega-3 fatty acids continued with time. As a result of the changes in fatty acid composition, the lipid classes of both plasma and plaque had a higher unsaturation index in the fish oil-fed group.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: The results indicate that fish oil feeding may reduce blood pressure by decreasing vascular smooth muscle reactivity to noradrenaline in resistance vessels by inhibition of an endothelium‐derived cyclo‐oxygenase product, such as TxA2 or PGH2 in conduit vessels.
Abstract: 1. To examine possible mechanisms of antihypertensive effects of feeding fish oil rich in n-3 fatty acids, we have studied vascular reactivity of aortic rings and perfused mesenteric resistance vessels of spontaneously hypertensive rats (SHR) given such a diet. 2. In two experiments, rats were fed a semi-synthetic diet containing either 'fish oil' (10 and 20% by weight) or hydrogenated coconut oil (control) (10 and 20%) for 4 weeks. 3. Blood pressure rose significantly less in the fish oil group than in controls in both experiments. 4. Aortic rings from control rats showed endothelium-dependent relaxations to low concentrations of acetylcholine (ACh) but relaxed less at higher concentrations. In contrast, rings from the fish oil group had relaxations which increased through the range of concentrations used. Indomethacin (10 microM) also increased the relaxation responses seen in rings from control rats, suggesting that fish oil inhibits a contractile cyclo-oxygenase product. This contractile substance may be thromboxane A2 (TxA2) or its endoperoxide precursor, prostaglandin H2 (PGH2) as aortic incubates and serum levels of TxB2 (the stable product of TxA2) were greatly reduced in fish oil-fed rats, and the decrease of relaxant responses to high concentrations of ACh were also blocked by a TxA2/PGH2 receptor blocker (SQ 29548). 5. In contrast to aortic rings, perfused preconstricted mesenteric resistance vessels of control rats relaxed to ACh in a similar fashion to tissues from fish oil-fed rats. However, in this preparation, fish oil feeding enhanced relaxations to sodium nitroprusside (SNP) and contractile responses to noradrenaline were less than controls.(ABSTRACT TRUNCATED AT 250 WORDS)
01 Oct 1991
TL;DR: In short-term clinical studies, omega-3 polyunsaturated fatty acids seem to diminish cyclosporine-induced nephrotoxicity and the attendant complication of hypertension, to inhibit inflammatory and atherogenic mechanisms in lupus nephritis, and to preserve renal function and reduce proteinuria in IgA nephropathy.
Abstract: Omega-3 polyunsaturated fatty acids are among new treatments being tested for efficacy in immune renal disease. The principal omega-3 polyunsaturated fatty acids are eicosapentaenoic acid and docosahexaenoic acid. They are derived from alpha-linolenic acid, which is found mainly in marine lipids. Eicosapentaenoic acid and docosahexaenoic acid undergo biologic transformation into trienoic eicosanoids that alter inflammatory mediators and vascular reactivity, both of which are important in the pathogenesis of certain glomerular immune diseases. Investigators have shown that proteinuria was prevented and survival was prolonged in autoimmune models of nephritis after dietary supplementation with fish oil. Furthermore, vascular damage may be modified by the influence of eicosapentaenoic acid and docosahexaenoic acid on blood rheology, aggregation of platelets, and plasma lipids. In short-term clinical studies, omega-3 polyunsaturated fatty acids seem to diminish cyclosporine-induced nephrotoxicity and the attendant complication of hypertension, to inhibit inflammatory and atherogenic mechanisms in lupus nephritis, and to preserve renal function and reduce proteinuria in IgA nephropathy. Long-term clinical trials for testing fish oil in these three clinical conditions are under way to confirm or refute these apparent beneficial therapeutic results.
TL;DR: It is suggested that a diet high in fish oil was associated with less colon cancer and monounsaturated fat promotes colon tumors and N-3 polyunsaturated fat inhibits colon tumors.
Abstract: High‐fat, high‐cholesterol diets have been linked to colon cancer in both epidemiological and animal studies. Saturated and N‐6 polyunsaturated fats have both been implicated as playing causative roles. Epidemiological studies have shown a reduced colon cancer incidence in populations consuming a large quantity of N‐3 polyunsaturated fat. This study asked whether N‐3 polyunsaturated fat found in fish oil would also be associated with reduced colon cancer in animal studies. 1,2‐Dimethylhydrazine was used to induce colon cancer in mice fed three high‐fat, high‐cholesterol diets (beef tallow, safflower oil, and fish oil) and one low‐fat, cholesterol‐free diet (soybean oil). Colon adenocarcinomas developed in 55% of mice fed tallow, 48% of those fed low‐fat diets, 33% of those fed safflower oil, and 18% of those fed fish oil (p < 0.05). Tumors per animal were also greatest in mice fed tallow and fewest in those fed fish oil (p < 0.05). Plasma cholesterol levels were significantly higher in mice fed t...
TL;DR: In this paper, individual and combined effects of ascorbic acid and δ-tocopherol on the autoxidation of fish oil have been evaluated with the induction period monitored by Rancimat.
Abstract: Individual and combined effects of ascorbic acid andδ-tocopherol on the autoxidation of fish oil have been evaluated with the induction period monitored by Rancimat. The antioxidative efficiency of them was found to increase with increasing concentration.δ-Tocopherol and ascorbic acid acted highly synergistic with each other. Whenδ-tocopherol content was varied at a fixed content of ascorbic acid, the synergistic efficiency was generally 100% or more. On the other hand, when ascorbic acid content was varied at a fixed content ofδ-tocopherol, the synergistic efficiency rose sigmoidally with increasing concentration. We concluded that at least 0.01–0.02% ascorbic acid is required to obtain a considerable synergistic effect withδ-tocopherol in stabilizing fish oil.