Omega has many meanings dating back to the original Greek alphabet. From “great” to “the density of the universe,” omega often denotes a significant importance. Omega fatty acids are increasingly well-known as important to good health and, as such, have been infusing their importance into a variety of products, from dietary supplements to functional foods. Crucial to the success of the essential fatty acid (EFA) segment is retailer and consumer understanding of what the different omegas are, where they are found in the diet and in what ways they can balance good health.
As in the Ancient Greek language, where it is the last letter in the alphabet, in nutrition science omega denotes the end. Long chain polyunsaturated fatty acids (PUFAs) feature more than one double bond, which eliminates hydrogen and is thus not “saturated” with hydrogen like a saturated fat is; monounsaturated fats have only one double bond. In PUFAs, where the last double bond is positioned from the tail, or end, of the chain determines the type of omega fat. So a PUFA with a double bond three links from the end is called omega-3; a double bond six spots from the tail is an omega-6. These two PUFAS are considered EFAs, because they cannot be made from the body and must come from dietary sources. Humans do have the enzymes necessary to manufacture omega-9 fatty acids, but this ability can be diminished in certain populations, including seniors, so the 9s are often included in EFA supplements.
Humans may not be able to manufacture EFAs outright but, once digested, certain omega-3s and -6s can be converted to other forms in those categories. For instance, the body uses certain enzymes (desaturases) to change the master omega-3 alpha-linolenic acid (ALA) to the longer-chain PUFA eicosapentaenoic acid (EPA), which can be further “de-saturated” into docosahexaenoic acid (DHA). Likewise, the master omega-6 linoleic acid (LA) can be de-saturated to form gamma-linoleic acid (GLA).
These fatty acids make eicosanoids, which are molecules that help deliver messages in various body systems including the immune, inflammatory and central nervous systems. Each EFA makes a different class of these signaling molecules (prostaglandins, thromboxanes and leukotrienes)—some pro-inflammatory, some anti-inflammatory. The omega-6s tend to produce pro-inflammatory compounds, while omega-3s are more anti-inflammatory. Both types are important, as the body often uses inflammation to address certain acute issues, such as injury or infection. However, when the problem is under control, the body needs anti-inflammatory compounds to return things to normal.
Thus, both types of omegas are important to human health. However, many scientists, including nutritionists, have reported the modern diet has overloaded on omega-6s, which primarily come from vegetable oils—canola, safflower, corn, etc.—and contains less than ideal amounts of omega-3s, which come from marine food sources (fish, krill, etc.) and some plants (flax, kiwi, perilla, chia and others).