Inflammation, essential fatty acids

Fatty acids, such as linoleic, hnolenic, and arachidonic acids, contain two or more cis carbon-carbon double bonds and are referred to as polyunsaturated fatty acids. Several of these fatty acids, including linoleic and linolenic acids, are required nutrients for humans and must be part of a healthy diet. They are termed essential fatty acids, of which there are eight. These fatty acids cannot be synthesized by human beings but are essential to human health. Therefore, they must be consumed in adequate amounts in a healthy diet, specifically in the form of ingested plant-derived foods. A diet devoid of the essential fatty acids eventually results in a fatal condition characterized by inflammation of the skin (dermatitis), failure of wounds to heal, and poor growth. The essential fatty acids serve as precursors for complex molecules termed eicosanoids, to which we return below. 

Oils rich in essential fatty acids have been reported to suppress human granulocyte elastase, a tissue-degenerative enzyme that is released when tissue inflammation occurs (59). Oils rich in essential fatty acids, especially from animal origin, have been reported to suppress inflammation as well. Emu oil, for example, has been reported to have superior moismrizing and cosmetic properties in double-blind studies (60). It has also been reported that emu oil increases the proliferation of cells and the growth of hair follicles in laboratory rats (61). As is the case in pharmaceutical applications, the cosmetic properties of lipids synergistically increase when used in combination with phospholipids. Other oils used in cosmetics such as palm, sesame, safflower, borage, and coconut have been reported to increase the trans-dermal properties when used in combination with emu oil. The blend of ethyl... 

Omega-3 fatty acids are long-chain polyunsaturated fatty acids. The parent fatty acid of this group is alpha-linolenic acid, an essential fatty acid that the body is unable to synthesize alpha-linolenic acid can be converted in the body to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In animals and man, these acids reduce the production of several compounds that are involved in inflammation and thrombosis, such as eicosanoids (prostaglandins, thromboxanes, prostacyclin, and leukotrienes) and cytokines (interleukin II-l) (1). The extent of the conversion of alpha-linolenic acid to EPA and DHA is unclear. The conversion process appears to be inhibited by a high intake of linoleic acid, another essential fatty acid (2). In addition, alpha-linolenic acid is found in dark green vegetables and the oils of certain nuts and seeds, especially rape seeds and soya beans. 

The human body can synthesize all except two of the fatty acids it needs. These two, linoleic acid and linolenic acid, are polyunsaturated fatty acids that contain 18 carbon atoms (Table 8.1). Because they are not synthesized within the body and must be obtained from the diet, they are called essential fatty acids. Both are widely distributed in plant and fish oils. In the body, both acids are used to produce hormonelike substances that regulate a wide range of functions and characteristics, including blood pressure, blood clotting, blood lipid levels, the immune response, and the inflammation response to injury and infection. 

Histidine Essential fatty acids Omega 6 (a)6 or n-6) 28 1-4 % of total calories 8-12 Absolutely required. Enter cell membranes and affect many biochemical processes. The C20 acids are also converted to eicosanoids, signaling molecules that include prostaglandins and leukotrienes. Essential fatty acids protect against cardiovascular disease, disease, inflammation, and autoimmune reactions. 

Recent studies showed that AA, EPA, and DHA could give rise to anti-inflammatory compounds such as hpoxins (LXs) and resolvins that are essential to limit and resolve inflammation (3, 4). These studies imply that a deficiency of LXs and resolvins could lead to the perpetuation of inflammation and tissue damage. In the fight of these facts, it will be interesting to study whether a subclinical deficiency of PUFAs, decreased formation of LXs and resolvins, occurs in subjects who develop the various types of infections and their complications. Because, PUFAs can inactivate enveloped viruses including influenza, it is probably worthwhile to study the effect of various fatty acids on the bird flu virus, specifically, whether increased intake of these fatty acids could reduce the risk of flu. 

Arachidonic acid (20 4n - 6) is one of two major PUFA synthesized by the D6D/D5D pathway (Fig. 4). In many tissues and cell types, 20 4n - 6 is esterified to the sn-2 position of membrane PL, and is used for the eicosanoid-mediated signaling to perform specialized cell functions. Arachidonic acid esterified in PL is a storage form of this fatty acid and is hydrolyzed from the PL by phospholipases prior to enzymatic conversion into eicosanoids (Chapter 13). Eicosanoids are autocrine/paracrine hormones that mediate a variety of localized reactions, such as inflammation, homeostasis, and protection of digestive tract epithelium. D6D deficiency in humans leads to severe food intolerance and growth retardation (J. Nwankwo, 2003). These symptoms are reversed by arachidonic acid supplementation to the diet, which supports the essential role of eicosanoids in the protection of digestive tract mucosa in humans. 

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