Guide to Fats 3: Essential Fatty Acids: Omega-3

About omega-3 fatty acids Omega-3 fatty acids are polyunsaturated. They are found in cold-climate seed and nut oils, the brains of grass-fed ruminants, the oils of carnivorous fish and cold-water plankton. Little fish eat plankton; big fish eat little fish … and omega-3 travels up the food chain. The main forms of omega-3 are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). Converting ALA to EPA, DPA and DHA ALA is found in seeds, nuts and leafy greens. ALA is an 'essential fatty acid' because our bodies can't synthesise it; we must eat it. ALA is the 'parent molecule' for EPA, DPA and DHA – the 'elongated' (or long-chain) forms of omega-3 our bodies can actually use. EPA, DPA and DHA form powerful, anti-inflammatory prostaglandins (type 3 prostaglandins) that influence events throughout the body. Technically, our bodies can convert ALA from plant foods to longer-chain EPA, DPA and DHA. In actuality, conversion is often poor. Why? ALA needs certain enzymes to 'elongate' to EPA, DPA and DHA. But linoleic acid (LA), the parent molecule of the omega-6 family, competes for the same enzymes to elongate to gamma-linolenic acid (GLA) and arachidonic acid (AA) and usually wins through sheer force of numbers. The omega-3:omega-6 ratio The omega-3:6 ratio in the modern diet is 1:10 or greater. However, we evolved to eat a ratio of 1:2. The modern ratio interferes with omega-3 conversion, as do other consequences of our diet, such as insulin resistance, nutrient deficiencies and inflammation. In addition, man-made trans fats inhibit one of the conversion enzymes altogether. The result? More omega-6 LA is converted to arachidonic acid (AA) than it should be. Less omega-3 is converted to EPA, DPA and DHA than it should be. While prostaglandins synthesised from omega-3 are anti-inflammatory, prostaglandins derived from AA promote inflammation in certain tissues. Excess omega-6 + insufficient omega-3 + man-made trans fats = a chronic state of low-grade inflammation that promotes disease. This is why 'pre-converted' EPA, DPA and DHA from fish and krill oils are often recommended for omega-3 fatty acids. EPA, DPA and DHA EPA plays a 'functional' role in the body. EPA prostaglandins are potent, improving mood and reducing pain and inflammation. DHA is more 'structural'. Our brains are built of DHA. DHA levels at birth can predict a child's thinking speed at age eight, so it is vital in pregnancy and early childhood. DHA is also a key component of the myelin sheath that protects neurons. Lesser-known DPA is rich in wild salmon, seal blubber and breast milk. DPA is more effective than EPA and DHA at thinning blood and slowing arterial lesions, so high DPA levels can lower heart disease risk. DPA inhibits the formation of blood supply to tumours. It can even be converted to EPA and DHA. Most fish and supplements contain EPA and DHA. Wild salmon and salmon oil contain DPA too. Benefits and deficiencies According to research, the benefits of omega-3 include: reduced risk of cardiovascular disease due to improved heart rhythm, anti-inflammatory effects and blood thinning; beautiful skin and hair; improved hydration; better energy and stamina; recovery from fatigue; alertness; good memory, focus and concentration; better mood and motivation; better health in pregnancy; good foetal brain development; protection from early childhood illnesses; increased childhood IQ; reduced hyperactivity, anxiety and aggression; reduced hunger and cravings; prevention of leaky gut and allergies; prevention of PMS (with omega-6 GLA); increased fertility; killing infectious organisms; protection from DNA damage; inhibited cancer cell growth; improved wound healing; and anti-inflammatory painkilling. Phew! Omega-3 deficiency, especially when coupled with excessive and/or damaged omega-6 fats, has been shown to increase depression, hostility, aggression, suicide risk and the murder rate (OK, start with the biggies!); and contribute to heart disease, cancer, Alzheimer's, poor concentration, failing memory, rheumatoid arthritis, diabetes, ulcerative colitis, weight gain, joint pain, dry skin, dry hair, brittle nails, allergies, eczema, inflammatory diseases, and a host of other illnesses. Food sources ALA: flax, hemp and chia seeds and their oils; perilla oil; walnuts and walnut oil; leafy greens – especially summer and winter purslane (available from McNally's Family Farm at Temple Bar and Dun Laoghaire markets) NB Hemp and chia offer a fine ratio of omega-3:6 fatty acids. Walnuts contain both in abundance. Udo's Oil sports a good balance of vegetarian omega 3-6-9. (Chia seed also contains valuable antioxidants.) EPA and DHA: anchovies; sardines; herring; mackerel; trout; salmon; fish roe; purified fish oil; salmon oil; krill oil; the flesh and brains of organic, grass-fed ruminant animals; and algae-derived DHA supplements (ask you-know-who for advice). Cod liver oil (CLO) also contains omega-3 fatty acids but there is a danger of getting too much fat-soluble vitamin A and D, especially in early pregnancy. There are purity concerns, too. DPA: wild salmon; Patrick Holford's Essential Omegas; seal oil supplements (forbidden in the EU) NB Big fish, e.g. tuna, king mackerel, swordfish, etc. accumulate mercury, PCBs, dioxins and other pollutants. Nasty stuff. Select smaller fish or – better still – purified fish or krill oil supplements. (Krill oil contains valuable antioxidants and phospholipids for easy absorption.) Food sources should be ultra-fresh and oils should be unrefined and cold-processed. Vegetarians and vegans So important are omega-3 fatty acids that vegetarians and vegans need non-animal sources of these beauts. That means plenty of ALA-rich foods (see above) to convert to EPA, plus DHA supplements sourced from algae. Veg*ns also need small quantities of healthy omega-6 fats (see Omega-6 blog) and zero damaged omega-6s (i.e. refined vegetable oils, partially hydrogenated plant-based spreads, vegetable shortening, etc.). Controlling insulin resistance should help conversion: check out Patrick Holford, The Low-GL Diet Bible for more information. Stability and cooking Heat, light and air trigger rancidity in omega-3. Refrigerate foods and oils and obey the 'use-by' date. Chuck rancid seeds, nuts, oils and smelly fish. Never cook with omega-3 oils (e.g. flax). Whole foods stay fresh longer than oils. Our innards are warm. Antioxidant intake and omega-3 intake need to rise together to stop our fatty acids joining the Free Radical Party inside. Chia seed and krill oil contain antioxidants, as do brightly coloured fruits and veggies, green and white tea … and dark chocolate. Ya gotta have fun…! 😉 Go to… Guide to Fats 4: Essential Fatty Acids: Omega-6