Essential fatty acid interactions

There are many fatty acids found in nature. The two essential fatty acids are omega-3 and omega-6, which are necessary for good human health. However, the effects of the ω-3 (omega-3) and ω-6 (omega-6) essential fatty acids (EFAs) are characterized by their interactions. The interactions between these two fatty acids directly effect the signaling pathways and biological functions like inflammation, protein synthesis, neurotransmitters in our brain, and metabolic pathways in the human body. Arachidonic acid (AA) is a 20-carbon omega-6 essential fatty acid. It sits at the head of the "arachidonic acid cascade," which initiates 20 different signaling paths that control a wide array of biological functions, including inflammation, cell growth, and the central nervous system. Most AA in the human body is derived from dietary linoleic acid (18:2 ω-6), which is found in nuts, seeds, vegetable oils, and animal fats. During inflammation, two other groups of dietary essential fatty acids form cascade that compete with the arachidonic acid cascade. EPA (20:5 ω-3) provides the most important competing cascade. EPA is ingested from oily fish, algae oil, or alpha-linolenic acid (derived from walnuts, hemp oil, and flax oil). DGLA (20:3 ω-6) provides a third, less prominent cascade. It is derived from dietary GLA (18:3 ω-6) found in borage oil. These two parallel cascades soften the inflammatory-promoting effects of specific eicosanoids made from AA. The diet from a century ago had much less ω-3 than the diet of early hunter-gatherers but also much less pollution than today, which evokes the inflammatory response. We can also look at the ratio of ω-3 to ω-6 in comparison with their diets. These changes have been accompanied by increased rates of many diseases—the so-called diseases of civilization—that involve inflammatory processes. There is now very strong evidence that several of these diseases are ameliorated by increasing dietary ω-3. There is also more preliminary evidence showing that dietary ω-3 can ease symptoms in several psychiatric disorders.