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Alpha-linolenic Acid (alpha-linolenic + acid)
Selected AbstractsPostprandial lipemic response to alpha-linolenic acid rich oil, butter, and olive oilEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 9 2010Julia Svensson Abstract Postprandial lipemia varies with composition of dietary fat due to partitioning of fatty acids between ,-oxidation, incorporation into TAG, and tissue lipids. Effects of alpha-linolenic acid (ALA) are poorly characterized. Lipase-catalyzed transesterification was used to produce a novel ALA-oil (35% ALA) from rapeseed and linseed oil. We hypothesized a lower postprandial lipemic response with ALA-oil than with olive oil and butter due to higher ,-oxidation of ALA. A randomized crossover study with 26 healthy men compared the effects on plasma lipids 7,h after a breakfast containing 35,g ALA-rich oil, butter fat, or olive oil. The incremental area under curve for plasma TAG was lower with butter than with olive oil (34%, p<0.05) and ALA-oil (25%, ns). After ALA-oil percentage ALA increased, in TAG to a constant level of 7,mol% and in NEFA to 6% after 7,h. Since total NEFA increased with time the amount of exogenous ALA in NEFA also increased. Butter resulted in lower postprandial lipemia than the oils, the difference exceeding what is expected from the presence of short and medium chain fatty acids in butter. There was a considerable recirculation of ALA into the NEFA pool available for oxidation. Practical application: Enzymatic transesterification was used to produce a dietary oil rich in ALA. By randomizing the partitioning of ALA more evenly between the TAG molecules the risk of oxidation could be reduced. Analyses showed that the ALA-oil was stable during storage for at least 3 months. Enzymatic transesterification could be used as an advantageous method to design an ALA rich dietary oil with new properties regarding fatty acid composition, susceptibility to oxidation, and effects on blood lipids. [source] Fatty acid status in captive and free-ranging black rhinoceroses (Diceros bicornis)*JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3 2008M. Clauss Summary The fatty acid (FA) patterns of plasma/serum triglycerides (TG), phospholipids (PL) and cholesteryl esters (CE) of captive and free-ranging black rhinoceroses (Diceros bicornis) were investigated. Free-ranging animals (n = 28) stemmed from four different regions. Captive animals sampled included specimens from North American (n = 11) and three different European facilities (n = 6). The European animals were tested on 1,4 different diets, resulting in a total of 15 blood samples. Regardless of differences between the free-ranging animals from different regions, differences between captive and free-ranging animals were relatively uniform: captive animals had higher overall proportions of polyunsaturated fatty acid (PUFA), due to levels of linoleic acid (LA, 18:2n6) that were drastically increased as compared to free-ranging animals. In contrast, levels of alpha-linolenic acid (ALA, 18:3n3) were consistently lower on conventional zoo diets. n6/n3 ratios for TG, PL and CE were 1.6, 10 and 8 in samples from free-ranging animals, respectively, as compared to 4.1,16.3, 16,148 and 40,277 in samples from captive animals. There was a distinct correlation between the proportion of grain-based products (commercial concentrates, plain grains and bread) in the diets of the European animals and the measured levels of n6 PUFA. An animal from a facility with a very low proportion of grain products in the diet nevertheless had high LA readings, most probably due to the use of sunflower oil as 2% (dry matter basis) of its diet. One animal that received a high proportion of grass meal pellets due to an oral disease had increased ALA contents after the diet change. These results allow conclusions on the suitability of diets fed in captivity: the black rhinoceros is prone to several uncommon diseases that have been suspected to be linked to oxidative damage, possibly due to the disposition of this species to excessive iron storage. An unnatural dietary loading with PUFAs would exacerbate this problem. Additionally, n6 FAs are known as precursors of pro-inflammatory mediators, and their overrepresentation could therefore exacerbate any inflammatory processes. Therefore, the current practice of using grain-based feeds as major ingredients in captive rhinoceros diets is discouraged. Diet items containing ALA (a precursor of anti-inflammatory mediators) such as, fresh grass, fresh browse, the respective silages should be included at higher levels in diets for captive black rhinoceroses. Grass meal pellets, although a good source of ALA and linked with high levels of ALA in an animal of this study, must be chosen with care for black rhinoceroses due to their particular proneness for high iron contents. [source] Long-chain polyunsaturated fatty acids in a diabetic teenager during and after nine repeated episodes of diabetic ketoacidosisPEDIATRIC DIABETES, Issue 3 2009Éva Szabó Abstract:, Type 1 diabetes is often accompanied with acute hypoinsulinemia that may theoretically inhibit the conversion of essential fatty acids to their longer-chain metabolites. Previously, we found significant reduction in plasma arachidonic (C20:4n-6) and docosahexaenoic (C22:6n-3) acid values in a group of diabetic children during diabetic ketoacidosis. Here we report data on the changes of fatty acids in plasma phospholipids in a diabetic teenager during and after nine subsequent episodes of diabetic ketoacidosis (DKA). Plasma phospholipid linoleic acid (C18:2n-6) values significantly decreased [23.05 (1.05) versus 19.22 (3.22), % w/w, median (IQR), p < 0.01], while values of dihomo-gamma-linolenic acid (C20:3n-6) and docosatetraenoic acid (C22:4n-6) significantly increased [1.72 (0.44) versus 1.80 (0.63) and 0.40 (0.01) versus 0.45 (0.07), respectively, p < 0.05]. Values of alpha-linolenic acid (C18:3n-3) did not change, while values of docosahexaenoic acid were significantly higher after than during the ketoacidosis [1.57 (0.67) versus 1.87 (0.32), p < 0.05). These data obtained in the same patient during repeated episodes of diabetic ketoacidosis support the concept that hypoinsulinemia plays an important role in disturbances of essential fatty acid metabolism in diabetes. [source] Docosahexaenoic acid, the aquatic diet, and hominin encephalization: Difficulties in establishing evolutionary linksAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2007Bryce A. Carlson Distinctive characteristics of modern humans, including language, tool manufacture and use, culture, and behavioral plasticity, are linked to changes in the organization and size of the brain during hominin evolution. As brain tissue is metabolically and nutritionally costly to develop and maintain, early hominin encephalization has been linked to a release of energetic and nutritional constraints. One such nutrient-based approach has focused on the n -3 long-chained polyunsaturated fatty acid docosahexaenoic acid (DHA), which is a primary constituent of membrane phospholipids within the synaptic networks of the brain essential for optimal cognitive functioning. As biosynthesis of DHA from n -3 dietary precursors (alpha-linolenic acid, LNA) is relatively inefficient, it has been suggested that preformed DHA must have been an integral dietary constituent during evolution of the genus Homo to facilitate the growth and development of an encephalizing brain. Furthermore, preformed DHA has only been identified to an appreciable extent within aquatic resources (marine and freshwater), leading to speculation that hominin encephalization is linked specifically to access and consumption of aquatic resources. The key premise of this perspective is that biosynthesis of DHA from LNA is not only inefficient but also insufficient for the growth and maturation demands of an encephalized brain. However, this assumption is not well-supported, and much evidence instead suggests that consumption of LNA, available in a wider variety of sources within a number of terrestrial ecosystems, is sufficient for normal brain development and maintenance in modern humans and presumably our ancestors. Am. J. Hum. Biol. 19:132,141, 2007. © 2006 Wiley-Liss, Inc. [source] Optimization of flaxseed oil feeding time length in adult Nile tilapia (Oreochromis niloticus) as a function of muscle omega-3 fatty acids compositionAQUACULTURE NUTRITION, Issue 6 2009I.B. TONIAL Abstract This study evaluated the omega-3 (n-3) fatty acids and the proximate composition of muscle tissue of adult Nile tilapias to select the best feeding time length with a diet containing 70 (g kg,1 wt) flaxseed oil (FO). The results showed that dietary complementation with FO for 45 days is suitable for obtaining high levels of protein (164 g kg,1), total lipids (94 g kg,1), and ash (18 g kg,1). Furthermore, there was a significant difference (P < 0.05) in the reduction of n-6 and an increase in the concentration of n-3. With 45 days' time of FO feeding, fish weight was 532 g and it was improved by the incorporation of total n-3 (9.8%), consisting of alpha-linolenic acid (LNA; 6.3%), and n-3 very long-chain polyunsaturated fatty acid (n-3 VLC-PUFA; 3.5%), and including docosahexaenoic acid (DHA; 1.2%). This gave a better n-6/n-3 ratio (1.1) of muscle tissue, a more desirable ratio than the present ratio sometimes as high as 1 : 20 in human diets. The concentrations of n-3 VLC-PUFA were higher than those of native Brazilian freshwater fish. Thus, 45 days is the shortest time period required for the inclusion of FO oil in tilapia feed to raise the nutritional value of adult Nile tilapia. [source] | ||||||||||