1. Understanding Fatty Acids: Omega 3 and Omega 6 Stephen Alajajian, Dietetic Intern

2. In the 1970’s it was discovered that the Inuit had low rates of cardiovascular disease despite eating a high-fat diet. Their diet consisted mainly of fatty fish. A similar phenomenon was observed among the Japanese. Fish and heart health

3.  Omega-3 Fats: definition, function, benefits, chemical structure, food sources  Omega-6 Fats: “  Ratio of n-6/n-3: importance of, optimal ratio, distortions in the American diet, limitations  The bottom line: dietary recommendations  Choosing fish oil supplements  Summary Presentation Outline

4.  Polyunsaturated fats found primarily in fatty fish, grass-fed animal products and some plants  Essential to proper functioning of the body  Must be obtained by diet  Anti-inflammatory  Beneficial for cardiovascular health  Also called n-3 fats  Include ALA, EPA and DHA What are omega-3 fats?

5.  Important component of gray matter in the brain and of sperm  Role in vision  Cell membrane component, contribute flexibility  Precursor to messenger molecules called eicosanoids which can help to reduce inflammation What is the function of omega-3 fats?

6.  Comprised of prostaglandins, leukotrienes and thromboxanes  Fatty acids of 20 carbon length  “Hormone-like” messenger molecules synthesized and active within a cell  Perform various functions such as: lowering blood pressure, gastric secretion, raising body temperature, constricting bronchi, etc. What are eicosanoids?

7.  Omega-3 fatty acids act as precursors to eicosanoids that decrease inflammation  For example, the eicosanoids produced lower blood pressure, decrease body temperature, prevent platelet aggregation (and thus inhibit blood clotting), and down-regulate the immune system  This is what is meant by their “anti-inflammatory” effects Eicosanoids and Omega-3’s

8.  Cardiovascular benefits (hypolipidemic and antithrombotic)  Slows progression of rheumatoid arthritis  Decreases blood pressure  Beneficial for psoriasis (skin condition)  Effectiveness in the prevention and treatment of autoimmune diseases such as lupus and ulcerative colitis  Essential for a healthy pregnancy  Deficiencies correlated with depression  Potential benefits for cancer, kidney disease and other conditions What are the benefits of omega-3?

9.  Antithrombotic (prevent platelets from sticking together – worsening plaque)  Lower triglyceride levels  Lower LDL levels (only at high doses, > 10 g/day)  Reduce the release of pro-inflammatory cytokines which are involved in plaque formation How do omega-3’s prevent atherosclerosis?

10.  A fatty acid is a long chain of carbon atoms bonded to each other and to hydrogen  Omega means “end”  Omega 3 has a double bond on the 3 rd carbon from the end of the chain  Omega 6 fatty acids have a double bond on the 6 th carbon from the end Why are they called “omega-3”?

11. Note: the entire fatty acid is not shown. Why are they called “omega-3”?

12.  ALA is the plant form of omega-3, made in the chloroplasts of green plants such as grass and kale  Animals convert ALA into EPA and DHA which are found in fish and grass-fed animal products  Once converted, EPA and DHA play functional roles in the body as previously discussed  EPA is the precursor to the omega-3 derived eicosanoids What about ALA, EPA and DHA?

13. ALA, DHA and EPA Inefficient conversion in humans Plant sources such as: flax seed and green leafy vegetables Marine sources Eicosanoid production, attenuates inflammation Component of cell membranes, gray matter of brain, sperm, role in vision, etc.

14.  BEST FISH SOURCES: salmon, mackerel, sardines, bluefish, tuna  GOOD FISH SOURCES: herring, anchovy, pilchard, butterfish, rainbow trout  Range-fed meats, eggs and dairy (vs. grain fed)  Wild fish are higher in Omega-3’s and lower in Omega-6’s compared to farm-raised fish (some studies show omega 3 content about 1.5 X greater in wild fish) Best food sources of EPA and DHA

15. Omega-3’s: Wild vs. cultured fish

16.  Ground flax seed, chia seed, hemp seed, pumpkin seed, dark green leafy vegetables such as kale, collard greens and swiss chard, spirulina.  Advantage: fewer contaminants  Disadvantage: less efficient conversion to EPA and DHA Best sources of Omega-3’s: ALA

17.  Like Omega-3’s, absolutely essential in the diet for physiological functioning  Like Omega-3’s, polyunsaturated (multiple double bonds)  Also a component of cell membranes  Also a precursor to eicosanoids  Found ubiquitously in the American diet in the form of vegetable oils, also found in virtually all nuts and seeds Omega-6 fatty acids

18. Comparison of oils NOTE: Every fat or oil contains some of each kind of fat. Olive oil is not pure monounsaturated fat. Butter is not pure saturated fat. Flax is not pure n-3 fat.

19.  Linoleic and arachidonic acid (n-6) are converted into eicosanoids that promote inflammation by gearing up the immune system  NSAIDS (Aspirin and Ibuprofen) suppress these eicosanoids  Too much omega-6 compared to omega-3 causes inflammatory eicosanoids to predominate  Cell membranes reflect dietary intake. Too much n-6 and too little n-3 leads to rigid, inflexible membranes. Why does the ratio of n-6/n-3 matter?

20.  Highly speculative  Hunter-gatherer estimates: between 3:1 to 1:1  Some recent research suggests 4:1 may be an effective ratio for promoting health  4:1  prevention of cardiovascular disease  2-3:1  suppressed inflammation in rheumatoid arthritis  5:1  beneficial effect on asthma What should the n-6/n-3 ratio be?

21. Populationn-6/n-3 Ratio Paleolithic0.79:1 Greece prior to 19601.00-2.00:1 Japan4.00:1 Rural India5-6.1:1 United Kingdom and northern Europe 15.00:1 United States16.74:1 Urban India38-50:1 What is the n-6/n-3 ratio in the US? Source: Simopoulos AP. The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomed Pharmacother. 2008;56(8):365-79.

22.  Ubiquitous use of vegetable oil (cottonseed oil, soybean oil, corn oil, sunflower oil) in processed foods  Grain-fed animal products contain significant amounts of arachidonic acid (an omega-6)  Low intakes of fish, leafy green vegetables and grass- fed animal products  Production-driven agricultural practices Why is the American ratio so high?

23.  Unclear what the optimal ratio should be  Difficult to measure in an individual (food labeling does not specify, oils contain some of each and the ratios vary)  Critics contend that the ratio is of little use and has not been conclusively shown to correlate with inflammatory markers  May encourage people to avoid healthful foods that contain omega-6 What are some limitations of the n-6/n-3 ratio?

24.  Have been shown to lower LDL cholesterol (the “bad cholesterol”)  Linoleic acid converts to gamma- linoleic acid (GLA) before it converts to arachidonic acid and GLA is a precursor to a class of eicosanoids which are anti- inflammatory  Not black and white Omega-6 fats are not bad

25.  American diet is out of balance (n-6 to n-3) which may shift the body towards a state of inflammation  Increase intake of fatty fish (DHA and EPA) and plant sources of omega-3’s (ALA)  Choose grass-fed, free range animal products when possible  Continue eating healthful whole food sources of omega-6 including whole nuts, seeds and avocado  Decrease total omega-6 intake by minimizing processed foods made with vegetable oils, including margarine and fried restaurant food The bottom line

26.  No RDA for omega-3’s or omega-6’s  AHA: eat fatty fish 3.5 oz 2x/week OR up to 3g/day in supplements  WHO: 0.3-0.5g/day  European Food Safety Authority: 2-4g/day to lower triglycerides, 3g/day to lower BP  Estimated US intake: 0.1-0.2g/day (2011) vs. Japan (2g/day)  Anyone taking anticoagulants or with a vitamin K deficiency should exercise caution Omega 3’s: How much is enough?

27. Choosing a supplement

28.  Omega-3’s have many health benefits  Best sources are fatty fish, grass fed animal products, ground flax seeds and leafy greens  Too many n-6’s compared to n-3’s may tilt the body towards a state of inflammation  Increase low-mercury fatty fish in the diet for n-3’s and choose grass-fed animal products  Choose whole food sources of n-6’s like nuts and seeds instead of vegetable oils  Consider an omega-3 supplement In summary

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