From a historical perspective, wild dogs have survived for thousands of years on a natural selection of foods including wild game, plants and fish, providing a diet that was rich in a special group of fats containing 'Essential Fatty Acids'. This information is highly relevant as it is the same diet our modern pets were born to consume.
What are Essential Fatty Acids?
There are two types of essential fatty acids or EFAs - omega-3 and omega-6. Research is now suggesting there is also an essential balance of these EFAs, which means they are not only required for health, but they are required in a particular ratio to each other. For instance, the brain consists of an equal 1:1 ratio of omega 3 to omega 6 to maintain optimal functioning.
Both omega-3 (alpha-linolenic acid) and omega-6 (linoleic acid) are bountiful in the leafy plants consumed by roaming animals, providing nearly equal ratios of these EFAs. The fat in wild game and grazing ruminant contains roughly seven times more omega-3 fatty acids than animals raised for commercial meat. When domestic ruminants and chickens are deprived of greens, their meat and eggs also become low in omega-3s. Switching livestock from their natural diet of grass to large amounts of grain is one of the reasons our pet's modern diet is deficient in these essential fats. The other reason involves the fact that processing or cooking distorts EFAs into trans-fatty acids. High temperatures force unsaturated fat molecules to change from their healthy cis-forms (curved) to harmful trans-forms (straight). The trans fatty acid is unable to function naturally, resulting in a poisonous molecular change in the biological system.
There is another newly discovered "good" fat called "conjugated linoleic acid." The most abundant source of CLA in nature is also found in the meat and bone of ruminant grazing animals. Animals that naturally graze have from 3-5 times more CLA than animals fattened on grain. Superficially, CLA resembles linoleic acid however, they appear to have opposite effects. Whereas an overabundance of linoleic fatty acid promotes tumor growth, CLA blocks it. In fact, CLA may be one of our most potent cancer fighters.
Essential fatty acids are indispensable, because they provide the building blocks for numerous 'eicosanoids'. Many of these hormone-like chemicals are also called prostaglandins. Eicosanoids can lower blood pressure, raise body temperature, open or constrict bronchial passages, stimulate hormone production and sensitize nerve fibers. They are so dependent on dietary fat that we can directly attribute the specific activity of a particular eicosanoid to the class of fats from which it is derived. As such, we have the power to greatly enhance health by picking fats that in turn create beneficial eicsanoids. The secret is in keeping a dietary balance between the two major fatty acids, so that the body's eicosanoids are balanced.
Essential Fatty Acids & Their Function
Fatty acids are composed of long carbon chains with a methyl group at one end, and an acid group at the other. Saturated fatty acids contain no double bonds, whereas polyunsaturated fatty acids (PUFAs) have multiple double bonds. The more double bonds that an EFA contains, the greater the degree of unsaturation. The specific chemistry of the fatty acid, including the number of carbons and double bonds, affects how it functions in the animal body. PUFAs are categorized as either omega-6 or omega -3 depending upon the position of their first double bond from the methyl end. The most important PUFAs for animal nutrition in each series are as follows:
|Omega-6 Fatty Acid:
|Omega-3 Fatty Acid:
|Dihomogamma Linolenic Acid
Of the listed fatty acids, only omega-6 and omega-3 are categorized as "essential" because they cannot be synthesized in the body and therefore must be derived from the diet. Under optimal conditions, the remaining omega-3 and omega-6 fatty acids can be synthesized from linoleic acid and alpha-linolenic acid and may informally be referred to as "conditionally essential". After dietary ingestion of omega-6 and omega-3, mammalian tissue enzymes catalyze the conversion of these shorter chain PUFA into longer chain fatty acids through an alternating sequence of desaturation and elongation steps via the body's metabolic pathways. Under optimal conditions, the conversion to the longer chain PUFAs is efficient. However, in some situations commonly observed in dogs, the process is slow or totally lacking and dietary supplementation with longer PUFAs is necessary.
Cancer, arthritis, other inflammatory conditions, and immune system weaknesses are some of the most serious health problems associated with a lack of omega-3 fats. The best dietary sources are fish and fish oils or flaxseed. Three specific essential fatty acids are found in omega-3 fats and oils. They are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Flaxseed is a very good supplement source for ALA. For EPA and DHA, nothing beats cold water fish and fish oil supplements.
Fish oils are valuable in treating established cancer, as they can cut down the number of T suppresser cells (the cells that turn off the immune response). The most often recurring theme of all is fish oil's consistent ability to suppress inflammation. For example, in arthritis, fish oils effectively replace nonsteroidal anti-inflammatory drugs. EPAs both decrease pain and increase ease of movement. Eicosanoids created by overconsumption of omega-6 fats encourage the inflammation responsible for arthritis, so it makes sense to offset them with omega-3 eicosanoids from fish oils. Fish oils reduce the overproduction of inflammatory compounds that are associated with inflammatory bowel disease and decrease the damage these disorders can cause to the colon wall. An imbalance in the production of inflammatory hormones in the skin may cause a number of reactions. This can be helped by fish oil supplements. Proper kidney function can be also be supported by taking fish oils.
Flaxseed may also serve well. This eicosanoid precursor possesses many of fish oil's immune enhancing and anti-inflammatory effects. While the oil is remarkable, don't discard the value of the entire flaxseed. An excellent source of fiber, flax meal contains cancer opposing compounds called lignans. If using fresh flax seed in the diet, it should be milled prior to its use. It takes three tablespoons of ground flax seed to equal 1 tbsp of oil.
The other essential fatty acids come from linoleic acid and gamma-linolenic acid (GLA). Linoleic acid is found in sunflower, and safflower oils, while GLA is found in evening primrose and borage oils. The GLA oils are especially useful with arthritis, diabetes, and skin disorders. Only the omega-6's can convert themselves into GLA. However don't go overboard on these fatty acids, as they can give rise to an excess of certain inflammatory eicosanoids. How can an excess of omega-6 cause certain diseases, and still provide therapeutic assistance against the very health problems?
The answer is delta-6-desaturase (D6D). Without this enzyme, omega-6 fatty acids won't transform themselves into GLA. Dogs do possess the D6D enzyme, but its activity is often depressed. The loss of this enzyme may also be caused by diabetes, hypothyroidism, viral infection, or cancer. The enzyme is made with the help of vitamin C, vitamin B, zinc, and magnesium; a low amount of these nutrients will decrease the amount of D6D made by the body. Though some have argued that GLA competes with omega-3 fatty acids and renders them less effective, in reality they are synergistic. Most practitioners who endorse essential fats recommend both omega-3s and GLA, giving the body all the raw materials to make what eicosanoids it needs most.
Clinical research clearly supports a role for dietary omega-3 ( fish oils) as well as omega-6 (evening primrose) supplementation for the treatment of dermatological diseases in dogs. In addition to dermatological conditions, a variety of other abnormalities are seen when deficient in essential fatty acid deficient states. These include poor growth rates, weight loss, failure of ovulation and lactation, testicular degeneration, poor wound healing, and increased susceptibility to infections. In addition, it is becoming increasingly clear that a much wider range of conditions may respond to dietary supplementation of fatty acids in animals including cardiovascular disease, musculoskeletal problems, and neoplasia, as well as arthritis and certain renal disorders.
Because both GLA and EPA help to block the production of inflammatory substances, their use has been shown to reduce or eliminate the need for certain medications such as anti-inflammatory drugs (corticosteroids), and anti-allergics. It is suggested that the approximate GLA and EFA dosage levels will depend upon the animal and its condition. It is recommended that they are administered for at least six to eight weeks before assessing the response.