scholarly journals Dietary linoleic acid at high and reduced dietary fat level decreases the faecal excretion of vitamin E in young rats

1997 ◽  
Vol 77 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Lilian B. M. Tuburg ◽  
Edward Haddeman ◽  
Gerard A. A. Kivits ◽  
Jan A. Weststrate ◽  
Elizabeth J. Brink
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Vitamin E ◽  
Dietary Fat ◽  
High Fat ◽  
Dietary Linoleic Acid ◽  
Dietary Pufa ◽  
Faecal Excretion ◽  
Reduced Fat ◽  
Fat Diets

Vitamin E is the major lipid-soluble antioxidant in human subjects and is crucial in protecting polyunsaturated fatty acids (PUFA) against lipid peroxidation. Dietary PUFA have been suggested to inhibit the absorption of vitamin E. The present study in young male rats was designed to investigate the effect of increasing concentrations of dietary linoleic acid on the faecal excretion of vitamin E. The rats were fed on semi-synthetic diets containing two concentrations of fat (59 g/kg diet, 15 energy % (en%) or 131 g/kg, 30 en%) for 3 weeks. Triacylglycerol rich in linoleic acid was added at the expense of triacylglycerol rich in saturated fatty acids to obtain dietary concentrations of 13,39 or 66 g linoleic acid/kg diet for the high-fat diet (131 g fat/kg) and 12, 24 or 36 g linoleic acid/kg diet for the reduced-fat diet (59 g fat/kg). The results from the present study demonstrate that the faecal excretion of vitamin E was significantly lower in rats fed on diets with high levels of linoleic acid compared with rats fed on lower levels of linoleic acid irrespective of the dietary fat content. The concentration of vitamin E in liver and plasma was significantly lower in animals fed on the highest concentration of linoleic acid compared with those fed on the lowest level. Results from the present study also demonstrate that at the same concentration of linoleic acid, the faecal excretion of vitamin E in rats fed on reduced-fat diets was significantly lower than in rats fed on high-fat diets. Our findings indicate that the apparent absorption of vitamin E is not inhibited by dietary PUFA. Results from the present study also demonstrate that a reduction of dietary fat content from 30 en% to 15 en% does not lower the apparent absorption of vitamin E

scholarly journals Vitamin E function and requirements in relation to PUFA

2015 ◽  
Vol 114 (8) ◽  
pp. 1113-1122 ◽  
Author(s):  
Daniel Raederstorff ◽  
Adrian Wyss ◽  
Philip C. Calder ◽  
Peter Weber ◽  
Manfred Eggersdorfer
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Vitamin E ◽  
Animal Studies ◽  
Published Data ◽  
Dietary Linoleic Acid ◽  
Dietary Pufa ◽  
Pufa Intake ◽  
Degree Of Unsaturation ◽  
Lipophilic Antioxidant

AbstractVitamin E (α-tocopherol) is recognised as a key essential lipophilic antioxidant in humans protecting lipoproteins, PUFA, cellular and intra-cellular membranes from damage. The aim of this review was to evaluate the relevant published data about vitamin E requirements in relation to dietary PUFA intake. Evidence in animals and humans indicates a minimal basal requirement of 4–5 mg/d of RRR-α-tocopherol when the diet is very low in PUFA. The vitamin E requirement will increase with an increase in PUFA consumption and with the degree of unsaturation of the PUFA in the diet. The vitamin E requirement related to dietary linoleic acid, which is globally the major dietary PUFA in humans, was calculated to be 0·4–0·6 mg of RRR-α-tocopherol/g of linoleic acid. Animal studies show that for fatty acids with a higher degree of unsaturation, the vitamin E requirement increases almost linearly with the degree of unsaturation of the PUFA in the relative ratios of 0·3, 2, 3, 4, 5 and 6 for mono-, di-, tri-, tetra-, penta- and hexaenoic fatty acids, respectively. Assuming a typical intake of dietary PUFA, a vitamin E requirement ranging from 12 to 20 mg of RRR-α-tocopherol/d can be calculated. A number of guidelines recommend to increase PUFA intake as they have well-established health benefits. It will be prudent to assure an adequate vitamin E intake to match the increased PUFA intake, especially as vitamin E intake is already below recommendations in many populations worldwide.

scholarly journals Phospholipid fatty acids of brain and liver are modified by α-tocopherol and dietary fat in growing chicks

1996 ◽  
Vol 76 (1) ◽  
pp. 109-122 ◽  
Author(s):  
H. Fuhrmann ◽  
H. P. Sallmann
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Vitamin E ◽  
Dietary Fat ◽  
Phospholipid Fatty Acid ◽  
Tocopherol Content ◽  
Phospholipid Fatty Acids ◽  
Dietary Fatty Acids ◽  
Phospholipid Fatty Acid Composition ◽  
Liver Membranes

Dietary fatty acids modify phospholipid fatty acids in brain and liver of growing chickens post-hatching.The effect of vitamin E deficiency on this process is unknown and may be relevant to the pathogenesis of chick nutritional encephalomalacia (NE). Therefore laying hens received a diet low in vitamin E (10 mg α-tocopherol/kg feed). Resulting chicks were assigned to nine dietary groups each fed with either oleic (18:ln-9, 58 g/kg), linoleic (18:2n-6, 57 g/kg) or linolenic (18:3n-3, 56 g/kg) acid together with 5, 25 or 125 mg α-tocopherol/kg feed. NE affecting the cerebellum only occurred in the group given linoleic acid and 5 mg α-tocopherol/kg.In l-d-old chicks and after 1 and 2 weeks the phospholipid fatty acid composition of liver, cerebrum and cerebellum (additionally after 3 weeks) was determined. The feed fatty acids were incorporated into the liver very efficiently during the first week of life. Unsaturation of liver membranes decreased in the orderdietary linolenic >linoleic >oleic acid. In liver, also, the effect of α-tocopherol supplementation on phospholipid fatty acids was most pronounced. Theunsaturation index increased during deficiency, whereas n-9 fatty acids decreased. In the chicken brain the alterations were delayed and less distinct. The cerebellum phospholipids were rich in n-9 fatty acids and as a whole more saturated in comparison with the cerebrum. Cerebellar unsaturation increased when linolenic or linoleic acid was given. However, NE-producing dietary conditions were not accompanied by specific alterations in cerebellar phospholipid fatty acids due to the α-tocopherol content of the diet. Rather the alterations of membrane fatty acids in the liver seem to play a role in the pathogenesis of NE.

scholarly journals Effects of dietary fat and conjugated linoleic acid on plasma metabolite concentrations and metabolic responses to homeostatic signals in pigs

2002 ◽  
Vol 88 (6) ◽  
pp. 625-634 ◽  
Author(s):  
E. Ostrowska ◽  
R. F. Cross ◽  
M. Muralitharan ◽  
D. E. Bauman ◽  
F. R. Dunshea
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Plasma Glucose ◽  
Dietary Fat ◽  
De Novo ◽  
Lipid Synthesis ◽  
High Fat ◽  
Triacylglycerol Synthesis ◽  
High Fat Diets ◽  
Fat Diets

Sixteen female cross-bred (Large White × Landrace) pigs (initial weight 65 kg) with venous catheters were randomly allocated to four treatment groups in a 2×2 factorial design. The respective factors were dietary fat (25 or 100 g/kg) and dietary conjugated linoleic acid (CLA; 0 or 10 g CLA-55/kg). Pigs were fed every 3 h (close to ad libitum digestible energy intake) for 8 d and were bled frequently. Plasma glucose and non-esterified fatty acid (NEFA) responses to insulin and adrenaline challenges were determined on day 8. Plasma concentrations of NEFA were significantly increased (10·5 and 5·4 % for low- and high-fat diets respectively, P=0·015) throughout the experiment, suggesting that there was a possible increase in fat mobilisation. The increase in lipolysis, an indicator of ß-adrenergic stimulated lipolysis, was also evident in the NEFA response to adrenaline. However, the increase in plasma triacylglycerol (11·0 and 7·1 % for low- and high-fat diets respectively, P=0·008) indicated that CLA could have reduced fat accretion via decreased adipose tissue triacylglycerol synthesis from preformed fatty acids, possibly through reduced lipoprotein lipase activity. Plasma glucose, the primary substrate for de novo lipid synthesis, and plasma insulin levels were unaffected by dietary CLA suggesting that de novo lipid synthesis was largely unaffected (P=0·24 and P=0·30 respectively). In addition, the dietary CLA had no effect upon the ability of insulin to stimulate glucose removal.

Dietary Fat Intake, Supplements, and Weight Loss

2000 ◽  
Vol 25 (6) ◽  
pp. 495-523 ◽  
Author(s):  
David J. Dyck
Keyword(s):  
Weight Loss ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Dietary Fat ◽  
Fat Oxidation ◽  
Fat Content ◽  
High Fat ◽  
Underlying Assumption ◽  
High Fat Diets ◽  
Fat Diets

Although there remains controversy regarding the role of macronutrient balance in the etiology of obesity, the consumption of high-fat diets appears to be strongly implicated in its development. Evidence that fat oxidation does not adjust rapidly to acute increases in dietary fat, as well as a decreased capacity to oxidize fat in the postprandial state in the obese, suggest that diets high in fat may lead to the accumulation of fat stores. Novel data is also presented suggesting that in rodents, high-fat diets may lead to the development of leptin resistance in skeletal muscle and subsequent accumulations of muscle triacylglycerol. Nevertheless, several current fad diets recommend drastically reduced carbohydrate intake, with a concurrent increase in fat content. Such recommendations are based on the underlying assumption that by reducing circulating insulin levels, lipolysis and lipid oxidation will be enhanced and fat storage reduced. Numerous supplements are purported to increase fat oxidation (carnitine, conjugated linoleic acid), increase metabolic rate (ephedrine, pyruvate), or inhibit hepatic lipogenesis (hydroxycitrate). All of these compounds are currently marketed in supplemental form to increase weight loss, but few have actually been shown to be effective in scientific studies. To date, there is little or no evidence supporting that carnitine or hydroxycitrate supplementation are of any value for weight loss in humans. Supplements such as pyruvate have been shown to be effective at high dosages, but there is little mechanistic information to explain its purported effect or data to indicate its effectiveness at lower dosages. Conjugated linoleic acid has been shown to stimulate fat utilization and decrease body fat content in mice but has not been tested in humans. The effects of ephedrine, in conjunction with methylxanthines and aspirin, in humans appears unequivocal but includes various cardiovascular side effects. None of these compounds have been tested for their effectiveness or safety over prolonged periods of time. Key words: carnitine, conjugated linoleic acid, ephedrine, pyruvate, hydroxycitrate

scholarly journals Metabolism and secretory function of white adipose tissue: effect of dietary fat

2009 ◽  
Vol 81 (3) ◽  
pp. 453-466 ◽  
Author(s):  
Cláudia M. Oller do Nascimento ◽  
Eliane B. Ribeiro ◽  
Lila M. Oyama
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
White Adipose Tissue ◽  
Dietary Fat ◽  
Dietary Fatty Acids ◽  
Secretory Function ◽  
High Fat ◽  
Adipose Tissue Metabolism ◽  
Tissue Metabolism

Approximately 40% of the total energy consumed by western populations is represented by lipids, most of them being ingested as triacylglycerols and phospholipids. The focus of this review is to analyze the effect of the type of dietary fat on white adipose tissue metabolism and secretory function, particularly on haptoglobin, TNF-α, plasminogen activator inhibitor-1 and adiponectin secretion. Previous studies have demonstrated that the duration of the exposure to the high-fat feeding, amount of fatty acid present in the diet and the type of fatty acid may or may not have a significant effect on adipose tissue metabolism. However, the long-term or short-term high fat diets, especially rich in saturated fatty acids, probably by activation of toll-like receptors, stimulated the expression of proinflammatory adipokines and inhibited adiponectin expression. Further studies are needed to investigate the cellular mechanisms by which dietary fatty acids affect white adipose tissue metabolism and secretory functions.

Effects of high- and low-fat diets on the bioavailability of selected fatty acids, including linoleic acid, in adult men

1986 ◽  
Vol 6 (8) ◽  
pp. 931-955 ◽  
Author(s):  
Olukemi Olubajo ◽  
Mary W. Marshall ◽  
Joseph T. Judd ◽  
James T. Adkins
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Low Fat ◽  
Adult Men ◽  
Fat Diets

scholarly journals Effects of dietary fat quantity and composition on fasting and postprandial levels of coagulation factor VII and serum choline-containing phospholipids

2003 ◽  
Vol 90 (2) ◽  
pp. 329-336 ◽  
Author(s):  
Anja Schou Lindman ◽  
Hanne Müller ◽  
Ingebjørg Seljeflot ◽  
Hans Prydz ◽  
Marit Veierød ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Dietary Fat ◽  
High Fat Diet ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Coagulation Factor ◽  
Factor Vii ◽  
High Fat ◽  
Coagulation Factor Vii ◽  
Low Fat Diet

Dietary fat influences plasma levels of coagulation factor VII (FVII) and serum phospholipids (PL). It is, however, unknown if the fat-mediated changes in FVII are linked to PL. The present study aimed to investigate the effects of dietary fat on fasting and postprandial levels of activated FVII (FVIIa), FVII coagulant activity (FVIIc), FVII protein (FVIIag) and choline-containing PL (PC). In a randomized single-blinded crossover-designed study a high-fat diet (HSAFA), a low-fat diet (LSAFA), both rich in saturated fatty acids, and a high-fat diet rich in unsaturated fatty acids (HUFA) were consumed for 3 weeks. Twenty-five healthy females, in which postprandial responses were studied in a subset of twelve, were included. The HSAFA diet resulted in higher levels of fasting FVIIa and PC compared with the LSAFA and the HUFA diets (all comparisonsP≤0·01). The fasting PC levels after the LSAFA diet were also higher than after the HUFA diet (P<0·001). Postprandial levels of FVIIa and PC were highest on the HSAFA diet and different from LSAFA and HUFA (all comparisonsP≤0·05). Postprandial FVIIa was higher on the HUFA compared with the LSAFA diet (P<0·03), whereas the HUFA diet resulted in lower postprandial levels of PC than the LSAFA diet (P<0·001). Significant correlations between fasting levels of PC and FVIIc were found on all diets, whereas FVIIag was correlated to PC on the HSAFA and HUFA diet. The present results indicate that dietary fat, both quality and quantity, influences fasting and postprandial levels of FVIIa and PC. Although significant associations between fasting FVII and PC levels were found, our results do not support the assumption that postprandial FVII activation is linked to serum PC.

Effect of the physical form of a lipid supplement on the polyunsaturated fatty acids, including conjugated linoleic acid, in muscle tissues of red deer and sheep

2007 ◽  
Vol 2007 ◽  
pp. 15-15
Author(s):  
G. A. Romero-Perez ◽  
R. W. Mayes ◽  
J. R. Scaife ◽  
J .A. Milne
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Dietary Pufa ◽  
Lipid Source ◽  
Ruminant Species ◽  
Physical Form ◽  
Beet Pulp ◽  
Source Form ◽  
Lipid Supplement

Proportions of polyunsaturated fatty acid (PUFA) in ruminant tissues are generally low as dietary PUFA including linoleic acid (LA) and α-linolenic acid (ALA) undergo biohydrogenation to stearic acid in the rumen. Conjugated linoleic acid (CLA) is formed during biohydrogenation as an intermediate metabolite. Feeding PUFA-rich sources can enhance deposition in the tissues of ruminants (Bolte et al, 2002), but the degree of lipid hydrogenation may depend on the source form and the ruminant species (Rowell-Schäffer et al, 2001). Bolte et al, (2002) showed that oilseed-fed sheep had higher PUFA proportions in their tissues than sheep fed a beet pulp-based diet but Rowell-Schäffer et al (2001) found in deer tissues higher PUFA proportions than in those of sheep. Possible effects of the form of the lipid source and the ruminant species on the fatty acids deposited were tested.

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