Essential fatty acid requirements in human nutrition

1993 ◽  
Vol 71 (9) ◽  
pp. 699-706 ◽  
Author(s):  
Sheila M. Innis

Arachidonic acid (20:4ω−6) and docosahexaenoic acid (22:6ω−3) are major acyl components of cell membrane phospholipids, and are particularly enriched in the nonmyelin membranes of the central nervous system. Dietary deficiency of linoleic acid (18:2ω−6) and linolenic acid (18:3ω−3) during development has been shown to result in reduced levels of 20:4ω−6 and 22:6ω−3 in the developing central nervous system, and this has been associated with altered learning behaviour and visual function. Synthesis of 20:4ω−6 and 22:6ω−3 depends on the dietary intake of 18:2ω−6 and 18:3ω−3, respectively, and the activity of the fatty acid desaturase–elongase enzymes. Oxidation of 18:2ω−6 and 18:3ω−3 for energy, or direct acylation of 18:2ω−6 into triglycerides, cholesteryl esters, and phospholipids, could also influence the amount of 20:4ω−6 and 22:6ω−3 formed. The tissue levels of 20:4ω−6 and 22:6ω−3, or other (ω − 6) and (ω − 3) fatty acids, compatible with optimum growth and development or health are not known. The amount of preformed 22:6ω−3 in the diet of adults, infants fed various milks or formulae, or animals is reflected in the circulating lipid levels of 22:6ω−3. Human milk levels of (ω − 6) and (ω − 3) fatty acids vary, depending in part on the mother's diet. A valid, scientific approach to extrapolate dietary essential fatty acid requirements from the composition of human milk or the circulating lipids of infants fed different diets has not been agreed on. Current data suggest that fatty acid requirements for development of term-gestation piglet brain and retina are met with 5.0% dietary kcal (1 cal = 4.1868 J) 18:2ω−6 and > 1.0% kcal 18:3ω−3, As in rodents and non-human primates, a diet source of 20:4ω−6 and 22:6ω−3 does not seem essential for the developing piglet central nervous system. However, studies in very premature infants suggest these infants may benefit from a dietary source of 20:4ω−6 and 22:6ω−3. Whether the low 20:4ω−6 and 22:6ω−3 status is due to oxidation of 18:2ω−6 and 18:3ω−3 for energy, the effects of early intravenous feeding with lipid emulsions, rapid growth, or immaturity of physiological or metabolic pathways in very preterm infants is not yet known.Key words: linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, brain, retina.

2020 ◽  
Vol 21 (14) ◽  
pp. 4871
Author(s):  
Francesco Bordignon ◽  
Silvia Martínez-Llorens ◽  
Angela Trocino ◽  
Miguel Jover-Cerdá ◽  
Ana Tomás-Vidal

The present study evaluated the effects of wash-out on the fatty acid (FA) composition in the muscles of Mediterranean yellowtail. After 109 days during which fish were fed either a fish oil (FO)-based diet (FO 100) or a diet (FO 0) in which FO was completely substituted by vegetable oils, all fish were subjected to a wash-out with FO 100 diet for 90 days. The FA profile of muscles in fish fed FO 0 diet at the beginning of the experiment reflected that of dietary vegetable oils, rich in linoleic acid (LA), and α-linolenic acid (ALA), and was deficient in AA (arachidonic acid), EPA (eicosapentaenoic acid), and DHA (docosahexaenoic acid). No essential FA were fully restored in fish previously fed FO 0 diet on 45th or 90th day of wash-out. At the end of wash-out, the FA composition showed that AA, EPA, and DHA in the white muscles increased by +33%, +16%, and +43% (p < 0.001), respectively. Similarly, AA and DHA in the red muscles increased by +33% and +41% respectively, while EPA remained similar to fish fed FO 0 diet exclusively. Therefore, a 90-d wash-out can partially improve the FA profile in muscles of Mediterranean yellowtail previously fed vegetable oil-based diets.


1978 ◽  
Vol 40 (1) ◽  
pp. 155-157 ◽  
Author(s):  
A. G. Hassam ◽  
M. A. Crawford

1. Rats were fed on either a diet deficient in essential fatty acid (EFA) or one supplemented with dihomo-γ-linolenic acid (20:3,n-6) at levels that represented 0.25, 0.5, 1.0 and 2.0% of the dietary energy.2. Supplementation of the diet of EFA-deficient animals with 20:3,n-6 reversed most of the fatty acid changes induced in the liver phospholipid fraction.3. The EFA potency of 20:3,n-6 was found to be similar to that of γ-linolenic acid (18:3,n-6) which has been shown to be higher than that of linoleic acid (18:2,n-6).


2019 ◽  
Vol 59 (4) ◽  
pp. 1763-1766 ◽  
Author(s):  
Yasutake Tomata ◽  
Susanna C. Larsson ◽  
Sara Hägg

Abstract Purpose Observational studies have suggested that polyunsaturated fatty acids (PUFAs) may decrease Alzheimer’s disease (AD) risk. In the present study, we examined this hypothesis using a Mendelian randomization analysis. Methods We used summary statistics data for single-nucleotide polymorphisms associated with plasma levels of n-6 PUFAs (linoleic acid, arachidonic acid) and n-3 PUFAs (alpha-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, docosahexaenoic acid), and the corresponding data for AD from a genome-wide association meta-analysis of 63,926 individuals (21,982 diagnosed AD cases, 41,944 controls). Results None of the genetically predicted PUFAs was significantly associated with AD risk; odds ratios (95% confidence interval) per 1 SD increase in PUFA levels were 0.98 (0.93, 1.03) for linoleic acid, 1.01 (0.98, 1.05) for arachidonic acid, 0.96 (0.88, 1.06) for alpha-linolenic acid, 1.03 (0.93, 1.13) for eicosapentaenoic acid, 1.03 (0.97, 1.09) for docosapentaenoic acid, and 1.01 (0.81, 1.25) for docosahexaenoic acid. Conclusions This study did not support the hypothesis that PUFAs decrease AD risk.


1964 ◽  
Vol 42 (3) ◽  
pp. 309-316 ◽  
Author(s):  
U. K. Misra ◽  
D. A. Turner

Phosphatidyl ethanolamine and phosphatidyl serine extracted from dog bile have been separated by means of ammonium silicate column chromatography. Concentration of phosphatidyl serine in dog bile is about seven times higher than phosphatidyl ethanolamine. Fatty acid analysis by gas chromatography showed that phosphatidyl ethanolamine contains about 26% palmitic acid, 18% stearic acid, 11% linoleic acid, 2% linolenic acid, 9% arachidonic acid, 3% C22:5 fatty acid, and 6% C22:6 fatty acid. The concentrations of these fatty acids observed in phosphatidyl serine are different; palmitic acid represents about 43%, stearic acid 9%, linoleic acid 24%, linolenic acid a trace amount, and arachidonic acid 5%; C22:5 and C22:6 fatty acids are absent.


2003 ◽  
Vol 56 (1-2) ◽  
pp. 50-53 ◽  
Author(s):  
Vanja Ristic ◽  
Gordana Ristic

Introduction Hyperlipoproteinemia is a key factor in development of atherosclerosis, whereas regression of atherosclerosis mostly depends on decreasing the plasma level of total and LDL-cholesterol. Many studies have reported the hypocholesterolemic effect of linolenic acid. Types of polyunsaturated fatty acids (PUFA) Linoleic and ?-linolenic acids are essential fatty acids. The main sources of linoleic acid are vegetable seeds and of ?-linolenic acid - green parts of plants. ?-linolenic acid is converted to eicosapentaenoic and docosahexaenoic acid. Linoleic acid is converted into arachidonic acid competing with eicosapentaenoic acid in the starting point for synthesis of eicosanoids, which are strong regulators of cell functions and as such, very important in physiology and pathophysiology of cardiovascular system. Eicosanoids derived from eicosapentaenoic acid have different biological properties in regard to those derived from arachidonic acid, i.e. their global effects result in decreased vasoconstriction platelet aggregation and leukocyte toxicity. Role and significant of PUFA The n-6 to n-3 ratio of polyunsaturated fatty acids in the food is very important, and an optimal ratio 4 to 1 in diet is a major issue. Traditional western diets present absolute or relative deficiency of n-3 polyunsaturated fatty acids, and a ratio 15-20 to 1. In our diet fish and fish oil are sources of eicosapentaenoic and docosahexaenoic acid. Refined and processed vegetable oils change the nature of polyunsaturated fatty acids and obtained derivates have atherogenic properties.


1976 ◽  
Vol 36 (3) ◽  
pp. 479-486 ◽  
Author(s):  
C. B. Cowey ◽  
J. M. Owen ◽  
J. W. Adron ◽  
C. Middleton

1. Five groups of juvenile turbot (Scophthalmus maximus) which had been given a diet free of fat for 12 weeks were given diets in which the lipid component (g/kg) was: oleic acid alone 50, oleic acid 40+linoleic acid 10, oleic acid 40+linolenic acid 10, oleic acid 40+arachidonic acid 10 or oleic acid 40+cod-liver oil 10. These five experimental diets were given for 16 weeks.2. Weight gains were highest in the group given the diet containing cod-liver oil and lowest in the groups given diets containing oleic acid alone or oleic acid+linoleic acid. Weight gains in the groups given oleic acid+arachidonic acid or linolenic acid were markedly inferior to those of the group given oleic acid+cod-liver oil. It is concluded that arachidonic acid is inferior to polyunsaturated fatty acids of the ω3 series in maintaining growth rate in turbot.3. Fatty acid analyses of neutral lipids and phospholipids of liver and extrahepatic tissues did not suggest any evidence of desaturation of dietary oleic acid, linoleic acid or linolenic acid by the turbot. These experiments confirm previous isotopic evidence that turbot lack the necessary microsomal desaturases to perform this metabolic transformation.


2012 ◽  
Vol 7 (1) ◽  
pp. 19
Author(s):  
Raden Roro Sri Pudji Sinarni Dewi ◽  
Priadi Setyawan ◽  
Evi Tahapari ◽  
Adam Robisalmi ◽  
Nunuk Listiyowati

The aim of this research was to investigate the nutritive composition (especially fatty acids) in red tilapia that was reared in freshwater and brackishwater. The fatty acid contents were determined by gas chromatography. The fatty acids profile were -3 (linolenic acid, eicosapentaenoic acid/EPA, docosahexaenoic acid/DHA), -6 (linoleic acid, arachidonic acid/AA), and -9 (oleic acid). Red tilapia samples were obtained from Research Institute for Fish Breeding, Sukamandi, West Java (freshwater ponds) and Congot, Yogyakarta (brackishwater ponds; salinity 20 ppt). In this research, red tilapia reared in different ecosystems showed different fatty acid profiles. Red tilapia inhabiting brackishwater ecosystem has EPA (0.26±0.05%), DHA (3.42±0.26%), and linoleic acid (17.20±0.56%) content higher than freshwater ecosystem (EPA = 0%; DHA = 0.67±0.44%; linoleic acid = 9.08±4.76%), except for linolenic acid (0.30±0.15% vs 0.25±0.10%), arachidonic acid (0.77±0.39% vs 0.93±0.13%) and oleic acid (38.67±2.58% vs 37.44±0.74%). The ratio of -6/-3 in red tilapia inhabiting freshwater ecosystem was about 11/1. The culture tilapia in brackishwater ecosystem decrease -6/-3 ratio (4.5:1). So that for human health, it will be better to consume brackishwater red tilapia than freshwater red tilapia.


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