FATTY ACIDS omeg3 & 6

Fatty Acids ……… DEFINITION Fatty acid: a long, unbranched chain carboxylic acid, most commonly of 12 - 20 carbons, derived from hydrolysis of animal fats, vegetable oils, or phosphodiacylglycerols of biological membranes

Fatty acids - are components of triacylglycerols, sphingolipids and glycerophospholipids, Fatty acids differ from one another in: (1) Length of the hydrocarbon tails (2) Degree of unsaturation (double bond) (3) Position of the double bonds in the chain Prentice Hall c2002 Chapter 9 Fig 9.2

Omega-3, omega-6 and omega-9 Long Chain Fatty Acids are typically even numbered SATURATED - no C-C double bonds UNSATURATED - at least one C-C double bond Monounsaturated - only one C-C double bond Polyunsaturated - two or more C-C double bonds Omega-3, omega-6 and omega-9

Omega-3: The Good Fat While excessive fatty food intake can elevate cholesterol and triglyceride levels, not all fats are unhealthy. Omega-3 fatty acids may have significant benefits in lowering the risk of heart disease, the nation’s top killer. They may also protect against depression, dementia, cancer, and arthritis. Omega-3 fatty acids are found in higher amounts in salmon, walnuts, and spinach.

Omega-3 Supplements If you don't care to eat fish, you can use omega-3 supplements. One gram per day is recommended for people with heart disease. Ask your doctor before starting, for high doses can interfere with some medicines or increase the risk of bleeding. Some people taking fish oil supplements notice a fishy taste and breath. Read the label, since the amounts of EPA, DHA, or ALA vary greatly.

Fig. 9.3 Structures of three C18 fatty acids (a) Stearate (octadecanoate) (b) Oleate (cis-D9-octadecenoate) (c) Linolenate (all-cis-D9,12,15-octadecatrienoate) The cis double bonds produce kinks in the tails of unsaturated fatty acids Prentice Hall c2002 Chapter 9

Fatty Acids

Fatty Acids Among the fatty acids most abundant in plants and animals nearly all have an even number of carbon atoms, most between 12 and 20, in an unbranched chain the three most abundant are palmitic (16:0), stearic acid (18:0), and oleic acid (18:1) in most unsaturated fatty acids, the cis isomer predominates; the trans isomer is rare unsaturated fatty acids have lower melting points than their saturated counterparts; the greater the degree of unsaturation, the lower the melting point

Difference between Cis & Trans If the acyl chains are on the same side of the bond, it is cis-, example: oleic acid. if on opposite sides, it is trans-,  example: elaidic acid, the trans  isomer of oleic acid

Basically… “cis” means “same side,” which is the most common structure Basically… “cis” means “same side,” which is the most common structure. But trans fats have the hydrogen atoms on opposite sides, which can be a problem.

Clinical Significance Consumption of trans fatty acids  not good for health. Previously in Margarine  Higher number of Trans FA. Now soft margarine low in trans fatty acids or containing none at all.

Both observational studies and clinical trials have found that trans fats significantly increase your risk of heart disease. It is possible that trans fats cause insulin resistance and drive type II diabetes, but the results from human studies are mixed. Clinical trials and observational studies both indicate that trans fats increase inflammation, especially in people who are overweight or obese. Several review studies have concluded that a moderate intake of ruminant trans fats does not appear to be harmful

Hydrogenation Plant Hydrogenation involves: Heating oil Pressurizing oil hydrogen gas Using platinum catalyst Trans fats are a by product of hydrogenation 0 g trans fats does not mean zero It means <0.5 g per serving!

How Can Fatty Acids Modulate the Immune System? Why do we need immune modulation in the first place? Answer: Similar to avoid excessive, chronic inflammation which leads to tissue destruction. FAs such as DHA and EPA can reduce production of inflammatory cytokines (IL-6, IL-12, IL-23) FAs can increase phagocytic activity FAs can decrease lymphocytic proliferation FAs can influence immune cell migration