Pain: The Role of Fatty Acid Imbalances
Nutrition has seen many changes since early man, especially in the last 150 years. The dietary intake of modern society is lacking in several essential vitamins and nutrients, especially essential fatty acids (EFA). There are two types of EFAs required through dietary intake since your body cannot produce them; the omega-3 type, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the omega-6s, including linoleic acid (LA), Dihomo-gamma linolenic acid (DGLA) and arachidonic acid (AA).
Throughout the course of history, both types of EFAs (omega-3 and omega-6) were consumed in relatively similar quantities. Hunter-gatherers obtained omega-3s from foods such as fish, meat, wild plants, nuts and eggs. These foods provided plentiful amounts of EPA and DHA which are largely missing from today’s diet. Unfortunately, due to technological advances, the dietary needs of today’s society are met with cereal type grains, such as wheat and rice, which make up a whopping 75% of the worlds grain production. Defectively, cereal grains are extremely high in carbohydrates and omega-6 fatty acids, and severely low in omega-3s. This has led to a tremendous deficiency in omega-3 fatty acids, whereby the ratio of omega-3 to omega-6 is a shocking 1:15 instead of an optimal ratio of 1:1.
Fatty acid imbalances may actually form the foundation on which the proinflammatory state develops, as an excess of omega-6 fatty acids (linoleic acid and arachidonic acid) and a deficiency of omega-3 fatty acids may be involved the development of numerous diseases. For example, Eskimos eating their traditional diet, which is high in omega-3 fatty acids and very low in omega-6 fatty acids, are almost free of the chronic degenerative diseases that plague those in Western societies who consume virtually no omega-3 fatty acids and excessive amounts of omega-6 fatty acids. Eskimos do not suffer from heart disease, cancer, diabetes, appendicitis, diverticulitis, ulcerative colitis, gallstones, psoriasis, multiple sclerosis, or rheumatoid arthritis. Researchers indicate that the anti-inflammatory fatty acid balance of the traditional Eskimo diet provides them with protection from these proinflammatory degenerative diseases.
Notice that linoleic acid is the vegetable oil precursor of arachidonic acid, both of which are omega-6 fatty acids. Although seeds and grains are rich in linoleic acid, they are devoid of arachidonic acid. However, the consumption of seeds, seed oils, and grains will result in the production of arachidonic acid. This is because animal cells readily convert linoleic acid into arachidonic acid. Thus, there are 2 ways in which humans increase tissue concentrations of arachidonic acid. First, we consume foods rich in linoleic acid, which is subsequently converted into arachidonic acid; second, we consume liberal amounts of arachidonic acid-containing animal products, such as beef, chicken, and eggs. In contrast, we consume minimal amounts of foods that are rich in linolenic acid, eicosapentanoic acid (EPA), and DHA, such as green leafy vegetables, fish, and fish oil. The outcome of this eating pattern is an excessive production of proinflammatory eicosanoids from arachidonic acid and a deficiency in the production of anti-inflammatory eicosanoids, that is, a diet-induced proinflammatory state.
Medical research has clearly demonstrated that a decreased amount of omega-3 relative to omega-6 in the diet results in a shift of biochemical homeostasis and an increased risk of degenerative disease. One of the most damaging effects of EFA unbalance is the development of chronic inflammation. Advances in EFA science and extensive clinical research has established a link between chronic inflammation and a broad range of degenerative conditions such as heart disease, cancer, alzheimers, immune dysfunction, arthritis and psychiatric disorders
EFA’s and Chronic Inflammation
The body’s inflammatory response is modulated by the action of essential fatty acids from both the omega-3 family (EPA/DHA) and omega-6 family (AA/DGLA). The fatty acids AA, EPA, and DGLA (but not DHA) are metabolized via specific enzymes to produce a series of hormone-like molecules called eicosanoids which includes a large variety of different compounds consisting of prostaglandins (PG), thromboxanes (TX), leukotrienes (LTs) and lipoxins (LXs). The pathways for eicosanoid synthesis are catalyzed by the enzymes cyclooxygenase (COX) and lipoxygenase (LOX).
When the COX and LOX enzymes act on the omega-6 fatty acid AA they produce primarily inflammatory eicosanoids. EPA and DGLA on the other hand produce eicosanoids that are antiinflammatory. Due to the similar molecular structure of AA and EPA, these two fatty acids directly complete for incorporation into cellular membranes. Clinical investigations and experimental studies confirm that when diets are supplemented with omega-3 fatty acids, they partially replace the omega-6 fatty acids in the membranes of practically all cells
By displacing AA at the cellular level increased intake of EPA leads to a marked reduction of the potent pro-inflammatory AA derived eicosanoids. This is the primary action by which EPA is considered as anti-inflammatory. In addition to this displacement, EPA, and to lesser degree DGLA compete with AA for access to the LOX and COX enzymes, thus lowering the output of AA type eicosanoids.
The relationship between chronic inflammation and several diseased states has been both described and confirmed. In part by exerting anti-inflammatory effects, omega-3 fatty acids have proven to be effective in both the prevention and improvement of inflammatory related illnesses. It is clear that omega-3 fatty acids are extremely beneficial to the human organism, and will remain at the frontier of health research for some time to come.