What oils are best to get our omega 369s?
Before I answer your question directly, let’s do a little review. When we talk about dietary fats, most of the time we are referring to triglycerides, which are three fatty acids attached to a glycerol backbone.
Sometimes the fatty acids are all the same type, but most often there is some natural variation. Fatty acids are made up of carbon chains bonded to together, and due to the unique properties of carbon, leaves a space on the sides of the carbon atoms to accept hydrogen atoms on either side of the chain. A fatty acid carbon chain with all the side spots filled with hydrogen is a saturated fatty acid, whereas if one spot is empty, the fatty acid is unsaturated. If there is only one spot available, then the fatty acid is a monounsaturated fatty acid, and if there is more than one spot open it becomes a polyunsaturated fatty acid. Where there is no hydrogen bond to the a carbon, the two adjacent carbons will form a weak double bond. Thus for omega 3 fatty acids, which are polyunsaturated, the first double-bond occurs at the third carbon from the end, whereas for omega 6 it is at the sixth carbon, and for omega 9, indicates that the first double-bond in the fatty acid chain is at the ninth carbon. So let us not make too much hay from these terms.
What is more important is the fact that we do not synthesize the omega 3 and omega 6 fatty acids, and thus need to get them in our diet. Omega 9, however, which is oleic acid, is typically found in abundance in our diet in the form of fats like olive oil, so taking a supplement of omega 9 is not only silly but a very expensive way to get something which is easy to find. Omega 3 and 6 oils refer to linolenic and linoleic acid respectively, each the mother of two biosynthetic pathways that result in a number of different types of fatty acid. Linolenic acid, or the omega 3 fatty acid, gives rise to both eicosapentaenoic (EPA) and docosahexaenoic acids (DHA), whereas omega 6, or linoleic acid, is the mother of gamma linoleic acid (GLA).
All of these fatty acids have been well-studied, and apart from the fact that we need them in our diet, a number of effects have been noted in our physiology, particularly in the synthesis of locally acting hormone-like compounds called eicosanoids, which include a diverse group of compounds including prostaglandins, leukotrienes and thromboxanes. Both omega 3 and 6 oils have been shown to exert regulatory activities on eicosanoid production, and hence are regulators of physiological elements such as inflammation.
While both linolenic acid (omega 3) and linoleic acid (omega 6) have antiinflammatory properties, the omega 6 fatty acids can also be converted to arachidonic acid (AA), which is generally pro-inflammatory. What prevents the omega 6 oils from being converted into AA are numerous, but the key factor is the presence of omega 3s in our diet that act as a counter balance. The traditional human diet contained about equal proportions of omega 3 and 6 fatty acids, all in all, about 2:1 in favor of omega 6. Nowadays, with the advent of industrial agriculture and the modern diet, this ratio is skewed in favor of omega 6 fats such that many people are consuming 5, 10, 25 and even 50 times too much omega 6 fatty acids relative to omega 3s. This huge imbalance means that we really only need to supplement for omega 3s in a diet that is otherwise rich in omega 6s, which are found in most seed oils (e.g. safflower, sunflower), grains and cereals, as well as all animal produce that has been fed grain. Consuming a “balanced” 3-6-9 oil only makes sense (minus the omega 9) if this is our only source of fat – otherwise, it won’t function to balance essential fatty acid intake ratios that have been skewed through the modern diet. Once we avoid the pitfalls of the modern diet, and switch back to eating grass-fed animal products, small oily fish (smelts, sardines, herring), as well as lots of leafy greens and sea vegetables, our EFA ratios will be naturally balanced, and we can dispense with the EFA supplements all together.