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Polyunsaturated Fats Liquid at room temperature Two or more pairs of double bonds Lack four or more hydrogen atoms Unpaired electrons at the double bonds makes polyunsaturated fats highly reactive Largely found in safflower, sesame, corn, cottonseed, and soybean oils See on Exchange List Also found in meats, milk, eggs in form of Arachidonic Acid Large intake may increase the risk for some types of cancer (Enig 1978) linked to decrease in mortality (Hu 2005) Linolenic Acid (Omega-3 Fatty Acids) and Linoleic acid (Omega-6 Fatty Acids) Considered essential since our body's cannot make these fatty acids Polyunsaturated fatty acids are NOT resistant to heat-induced degradation, unlike Saturated fats (Grootveld 2001, Halvorsen 2011) Heat degrades polyunsaturated fatty acids to toxic compounds See Smoke Point and Heating Unsaturated Fats Also see Storing Unsaturated Fats. Omega-3 fatty acids Linolenic acid Type of Polyunsaturated fatty acid Triple unsaturated with three double bonds Omega number indicates position of first double bond Recommended intakes range is from 7 to 11 grams of omega-3 fatty acids each week Forms ALA (alpha-linolenic acid) produced by plants Animals convert ALA to DFA and EFA our ability utilize ALA diminishes with age DFA and EFA are animal forms Benefits Maintains cardiovascular health reduce triglyceride levels May be important in preventing many health problems including heart disease, rheumatoid arthritis, and cancer Maintains mental clarity Anti-inflammatory properties maintaining proper balance in prostaglandin production may help arthritis and lupus helps lubricate joints Metabolizing important sulphur-containing amino acids Omega-3 sources Fish and fish oils Salmon, mackerel, lake trout, herring, sardine, white (albacore) tuna, cod, halibut, mahi-mahi, catfish, flounder, tilapia, bluefish, whitefish Particularly wild caught Up to 12 oz (340 g) of fatty fish (low mercury) per week recommended Oily fish may contain harmful chemicals, such as dioxins and PCBs UK Food Standards Agency recommendation (FSA 2004) men eat no more than four portions of oily fish per week women and children no more than two Krill oil See Omega-3 content in Seafoods Walnuts, soybeans, beans, winter squash, avocados Seeds Flaxseed, kiwi seed, perilla seed, sacha inchi seed, and chia seeds Oils Canola, soybean, walnut, echium, and flaxseed oils High lignan flaxseed oil Canola Oil contain precursors of Omega-3 Fatty acids (DHA and EPA) See Comparison of Dietary and Cooking Oils Small concentrations in green leafy vegetables (kale, collard greens) and certain algae Foods fortified with DHA from algae fish get their DHA from algae Grass-feed animals Grass-feed animals provide more omega-3 fats, whereas grain fed animals provide more omega-6 fats Organic or flax eggs (Artemis 1992) organic eggs from free range hens allowed to feed on insects and green plants eggs from hens feed flax Supplements Consider taking fish oil or flaxseed oil if diet is insufficient in Omega-3 No mercury, dioxin, and PCBs often found in fish Patients with congestive heart failure or chronic recurrent angina should not be urged to consume fish oil or more fish (Leaf 2006) Omega-6 fatty acids Linoleic acid Family of unsaturated fatty acids Double unsaturated with two double bonds Omega number indicates position of first double bond Too much Omega-6 promotes inflammation Metabolites of omega-6 are more inflammatory (esp. arachidonic acid) than those of omega-3 Increases risk of coronary heart disease and other chronic illnesses may counter anti-inflammatory effects of omega-3 fatty acids must be accompanied by adequate Omega-3 to provide protective effects Possible increase risk for cancer May increase the likelihood of development of breast cancer in postmenopausal women (Sonestedt 2008). Sources Plant based cereals, some nuts, whole grains, and vegetable oils Animal based (Arachidonic Acid) meats, eggs, milk Grain feed animals contain more omega-6 fats and less omega-3 fats than grain feed animals Standard store bought eggs contain higher ration of Omega-6 to Omega-3 fats Farm raised fish contain more Omega-6 fatty acids compared to wild caught fish Omega-6 & Omega-3 Fatty Acid Balance Ratio of Omega-6 to Omega-3 in diet (Simopoulos 2012) Recommended ratio is 2:1 to 4:1 for overall diet Average Western Diet is 15:1-16.7:1 Early man's diet was approximately 1:1 Average modern diet contain too much Omega-6 and too little Omega-3 Partly due to modern farming and food production practices Omega-6 to Omega-3 ratios in oils: Flaxseed Oil (1:3) Canola Oil (2:1) Olive Oil (13:1) Corn Oil (46:1) Regulates cardiac pro inflammatory pathways A study using pigs suggests the potential cardiovascular benefit of Omega-3 fatty acid is achieved only when Omega-6 fatty acid is reduced concomitantly rather than fed with a high Omega-6 fatty acid diet (Ghosh 2007). Mental Health Possible link between depression and suicide and low omega-3 levels and/or higher omega 6/omega 3 ratio. (Colin 2003). Also see possible link between low blood cholesterol and risk of suicide Arachidonic Acid Arachidonic Acid is Omega-6, polyunsaturated fat Regulator of localized muscle inflammation and is necessary for the repair and growth of skeletal muscle tissue via conversion to active components such as prostaglandin PGF2alpha. Found in animal food including meats, organ meats, and eggs. Arachidonic Acid can be produced by the body from linoleic acid, an essential fatty acid. Other studies show that dietary linoleic acid intake does not appear to result in increased Arachidonic Acid in adipose tissue (Baylin 2004) In some mammals, such as cats, lack the ability to produce significant amounts of arachidonic acid, making it an essential part of their diet. Arachidonic acid in adipose had been correlated with incidence of myocardial infarctions (Baylin 2004) This relationship does not appear to be related to dietary intake of omega-6 fatty acids including linoleic acid. References Baylin A, Campos H (2004). Arachidonic acid in adipose tissue is associated with nonfatal acute myocardial infarction in the central valley of Costa Rica. J Nutr. 134(11),3095-9. Colin A, Reggers J, Castronovo V, Ansseau M (2003). Lipids, depression and suicide. Encephale. 29(1), 49-58. Ghosh S, Novak EM, Innis SM (2007). Cardiac proinflammatory pathways are altered with different dietary n-6 linoleic to n-3 alpha-linolenic acid ratios in normal, fat-fed pigs. Am J Physiol Heart Circ Physiol. 293(5), H2919-27 Simopoulos AP (2002). The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomed Pharmacother. 56(8),365-79. Sonestedt E, Ericson U, Gullberg B, Skog K, Olsson H, Wirfält E (2008). Do both heterocyclic amines and omega-6 polyunsaturated fatty acids contribute to the incidence of breast cancer in postmenopausal women of the Malmö diet and cancer cohort?. The International Journal of Cancer (UICC International Union Against Cancer) 123 (7), 1637–1643. Trappe TA, Fluckey JD, White F, Lambert CP, Evans WJ (2001). Skeletal muscle PGF(2)(alpha) and PGE(2) in response to eccentric resistance exercise: influence of ibuprofen acetaminophen. The Journal of Clinical Endocrinology and Metabolism 86 (10): 5067–70.