Essential fatty acids fish requirements

Although most hpids required for cell structure, fuel storage, or hormone synthesis can be synthesized from carbohydrates or proteins, we need a minimal level of certain dietary hpids for optimal health. These hpids, known as essential fatty acids, are required in our diet because we cannot synthesize fatty acids with these particular arrangements of double bonds. The essential fatty acids a-linoleic and a-linolenic acid are supphed by dietary plant oils, and eicosapentaenoic acid (ERA) and docosa-hexaenoic acid (DHA) are supplied in fish oils. They are the precursors of the eicosanoids (a set of hormone-like molecules that are secreted by cells in small quantities and have numerous important effects on neighboring cells). The eicosanoids include the prostaglandins, thromboxanes, leukotrienes, and other related compounds. 

TABLE 16 Essential Fatty Acid Requirements of Fish d ... 

Similar reversals of biochemical deficiencies of n-3 fatty acids or of total essential fatty acids have been studied in the rodent brain under somewhat different experimental conditions (Walker, 1967, Sanders etal., 1984, Youyou etal., 1986, Homo mayoun etal., 1988, Leyton et al., 1987). In the experiments by Youyou et al., complete recovery from the n-3 fatty acid deficiency, as measured by an increase of DHA and a decrease of 22 5n-6, required 13 wk as compared to 6-12 wk in our monkeys. There were major differences between this study and ours, which may be responsible for the different recovery rates observed. Most importantly, we fed monkeys fish oil, which is high in... 

However, replacement of marine fish oils with alternate oils of plant origin in the farmed fish feeds should occur not only to provide the sufficient quantities of lipids that meet fish essential fatty acid requirements for optimum growth, but also to maintain proper immune function in fish (Montero et al., 2003). Thus, the use of vegetable oils as a sole lipid source is limited. 

Although the use of Anemia in marine finfish larval rearing is almost ubiquitous, they are not a natural food source for any species and lack certain key nutrients required for the growth and development of marine fish larvae. The deficiency of Anemia in essential fatty acids has been long... 

Although not produced by the human body, these Essential Fatty Acids (EFAs) are required for normal brain function, growth, development, bone health, stimulation of skin and hair growth, regulation of metabolism, and maintenance of reproductive processes (University of Maryland Medical Centre, 2008). The health benefit provided by PUFAs is dependent on the precise PUFA being taken. The health benefits of the fish derived PUFAs eicosapentanoic acid and docosahexanoic acid are well described (Sanderson et al., 2002). There is interest in... 

Fatty acids that are required by the body but cannot be made in sufficient quantity from other substrates, therefore must be obtained from food and are called essential fatty acids. Essential fatty acids are polyunsaturated fatty acids and are the parent compounds of the omega-6 and omega-3 fatty acid series, respectively. Humans lack the ability to introduce double bonds in fatty acids beyond carbons 9 and 10, Two fatty acids are essential in humans, linoleic acid (LA) and alpha-linolenic acid (ALA). They are widely distributed in plant oils. In addition, fish, flax, and hemp oils contain the longer-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). 

Alpha-linolenic acid (18 3n-3) is an 18-carbon fatty acid with three double bonds at carbons 9, 12, and 15. It is an essential n-3 fatty acid that is a required nutrient for human beings and can be obtained through diets including both plant and animal sources. Alpha-linolenic acid can be converted by elongases and desaturases to other beneficial n-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosa-hexaenoic acid (DHA), which are implicated in normal brain development, normal vision, and a decreased risk of heart disease. Novel dietary sources of n-3 fatty acids are desired for those who do not consume adequate amounts of fish or fish-based food products rich in long-chain n-3 fatty acids. This section summarized fruit, spice, and herb seed oils rich in a-linolenic acid (18 3n-3). These include black raspberry, red raspberry, boysenberry, marionberry, blueberry, cranberry, sea buckthorn, basil, and hemp seed oils. 

The precursors of both n-6 and n-3 polyunsaturated fatty acids (PUFAs), linoleic acid and (/.-linolenic acid, respectively, are essential for mammals as they are required for normal physiological function and cannot be synthesized de novo (Holman, 1968). They can only be accumulated by placental transfer or by dietary intake. Once accretion of these fatty acids has occurred, metabolic, conservation and recycling pathways sustain them (B azan et al., 1994). Unlike mammals, plants can synthesize these precursor PUFAs (linoleic and a-linolenic acids) so they are found in abundance in the chloroplast membranes of plants, in certain vegetable oils, and in the tissues of plant-eating animals (Nettleton, 1991). The best sources of a-linolenic acid are vegetable oils, such as perilla (Yoshida et al., 1993) rapeseed (canola), linseed, walnut, and soybean (Nettleton, 1991). They are also abundant in shellfish, fish, and fish products and can be found in low amounts in green, leafy vegetables and baked beans (Nettleton, 1991 Sinclair, 1993). 

Omega-3 fatty acids are an essential form of polyunsaturated fat, meaning they are required for a healthy body but are not produced by the body. As a result, we must obtain omega-3 fatty acids from foods such as flaxseed, pumpkin seeds, soybeans, purslane, walnuts, algae, and hsh—particularly fatty fish (salmon, alba-core tuna, mackerel, sardines, herring, halibut, and lake trout). Alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are the three main types of omega-3 fatty acids consumed in foods. Of the three, EPA and DHA are easier for the body to use, therefore ALA is converted to either EPA or DHA by the body. 

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