Essential fatty acids are an important part of a human or pet's diet. We want to make sure and balance
the oils in the right ratio. Here is first a little background on oils and fats. (From "Spontaneous
Healing" by Andrew Weil, MD.) "Fats composed mainly of saturated fatty acids are solid at room temperature, and the greater the saturated fat content, the higher will be the temperature of melting.
Animal fats are highly saturated, as are the 2 vegetable fats: the oils of coconuts and palm kernels. At the opposite end of this chemical spectrum are the polyunsaturated vegetable oils, all of which stay liquid at colder temperatures. The lower the temperature at which solidification occurs, the greater the degree of
unsaturation. Corn, soy, sesame, sunflower and safflower are examples of polyunsaturated fats. In the middle of the spectrum are the vegetable oils composed primarily of monounsaturated fatty acids, those with just one double or tripe bond in the chain of carbon atoms; examples are olive, canola, peanut and avocado oils. Polyunsaturated oils are bad for us in other ways. They are chemically unstable, owing to their content of fatty acids with energetic double and triple bonds that tend to react with oxygen, resulting in toxic compounds that can damage DNA and cell membranes, promoting cancer, inflammation, and degenerative changes in tissue. Moreover, when unsaturated fatty acids are heated or treated with chemical solvents and bleaches, they tend to deform from a natural curved shape (called
cis-configuration) to an unnatural jointed shape (called the trans-configuration).
Trans-fatty acids, or TFA's, may be extremely toxic, even though medical scientists have been very slow to recognize the danger. The body builds cell membranes out of
cis-fatty acids and also uses them in synthetic pathways for hormones. We do not know what it does with
TFA's; if it tries to use them in the same ways, the result might be defective membranes and hormones... Remember that TFA's are rarely found in nature, only fats that have been subjected to unusual chemical and physical treatment.... You can avoid any danger by eliminating from the diet all margarine and solid vegetable shortening and products made from them, all products listing "partially hydrogenated" oil of any kind on the label, and all commercial brands of polyunsaturated vegetable oils (corn, soy, sesame, sunflower and safflower), since these have been extracted with heat and solvents that promote the formation of
TFA's.... Vegetable oils that are predominantly monounsaturated - olive, canola, peanut, avocado - do not pose the cardiovascular risk of saturated fats or the cancer risks of
A side note - a toxic mold, called aflatoxin, is commonly found in peanuts, corn and soy. If you do use peanuts or peanut oil, please make sure it is aflatoxin free. Also, canola is a very dangerous oil for humans and pets. If you would like some more info on canola please ask. So we have learned which types of oils (olive, peanut and avocado) are good for us and our pets, as well as the typical extraction methods (the ways to get the oil out of the seed) like chemical solvents (usually hexane) and heat are bad.
So where does this leave us? There are different types of fatty acids inside the fats themselves. We hear the most about Omega fatty acids, particularly omega 3, 6, and 9 fatty acids. You need all three for proper function, but you want more of the 3 than the 6. 9 we don't know much about. Omega 6 fatty acids can contribute to a hormone called prostaglandin E2 that, among other things, is an inflammatory agent. A wonderful benefit of the omega 3 fatty acids is the ability to inhibit some inflammation mediators.
Fish oil (not fish liver oil) and flaxseed oil have good amounts of omega 3's. The 2 acids that make up a fatty acid that are important here are EPA (eicosapentaenoic acid) and DHA
(docosahexanoic acid). These are readily available in fish oil, but the acids in flaxseed do need to be converted in the body to the active form. DHA and EPA have great anti-inflammatory effects. Flaxseed generally contains 9% saturated, 18% oleic acid, 16% omega 6 and 57% omega 3 fatty acids. However, flaxseeds themselves contain phytic acid that can hinder the absorption of such nutrients as iron, calcium, phosphorus and zinc. A good quality oil from the flaxseeds should be without phytic acids. You will find this oil refrigerated and in a dark glass bottle. It should be labeled as cold-pressed and organic, with no heat treatments or chemical solvents. Do not shake oils as to help reduce oxidation (which makes the oil spoil) and if it tastes bitter, it has spoiled (do not use).
A good quality fish oil is actually more species-specific and can be utilized better by our cats and dogs, but flaxseed oil is the next best thing. Finding good quality fish oil may be a very difficult thing. Studies are showing that appreciable levels of organochlorides are showing up in almost all marketed fish oils. These killer chemicals are stored up in the fat of any animal that consumes it, and since water is the dumping ground for industrial waste, much of it ends up in the bellies of fishes. Eating contaminated fish in a high amount can be correlated with higher risks of cancer, among other things. Your best bet for fish oil is to call up the producer of the oil and ask for data on organochloride testing. We personally rotate between flaxseed oil and fish oil so that hopefully all my bases are covered without an overdose of anything toxic.
Udo Erasmus, author of the book "Fats that heal, Fats that kill" has some interesting things to say on the subject of oils. The essential fatty acids, linoleic and linolenic acids, are necessary for the normal functioning of all cells, tissues, and organs. The richest source of
alpha-linoleic acid is flaxseed. Without EFA's, humans and animals alike would deteriorate until we die if we don't get any, would degenerate if we get too little, and must get at least minimum amounts to remain functional and must obtain optimal amounts from diet to remain healthy, as the body is unable to make the acids. However, EFA's are sensitive to destruction - particularly by light, air and high temperatures (think refining, hydrogenating and frying). Oils are best unrefined because the unrefined oils contain some 'minor' ingredients (minor in proportion, major in health impact), such as phytosterols, lecithin, Vitamin E, carotene and hundreds of other
phytochemicals. Refining destroys or leaves out these ingredients. The seeds used need to be organically grown as well to assure they are pesticide free. Some pet food companies boast of their kibble containing
EFA's. That sounds good but there are problems with that, including the fact that only one EFA is considered essential for our pets. If a kibble only contains one
EFA, the balance is upset - too much of one can cause a deficiency in the other.
Udo Erasmus has done a lot of research on nutrition and oils and even has a line of products available if you are interested in further reading. A note on Beta-carotene and cats: cats can't convert the Vitamin A found in plants to the active Vitamin A (retinol) that they need to use for eyesight, skin, coordination, etc. It is necessary to supply them with an animal-based source. Good source of this (as well as taurine, a necessary amino acid) are cod liver oil, eggs, meat, heart muscle and seafood. And indeed, it is hard for dogs and even humans to convert a lot of plant-based beta-carotene to retinol. Many things can hinder the conversion from the plant-based beta-carotene to retinol, so it is best to always provide the animal tissues for good Vitamin A. So this means supplementing with cod liver oil, as well as flaxseed oil and/or fish oil. Of course, many of the nutritional requirements for healthy cats and dogs are met by a raw and natural diet. Commercial diets can be lacking in many things, not just essential fatty acids.
Tiffani Beckman Copyright 1998 **Disclaimer - the advice given here should not be taken instead of good veterinary advice. Always consult your vet before supplementing with anything. **
Fatty acids are essential components of cell membranes and are an integral component of the intercellular barrier in the stratum corneum. This barrier is formed by extrusion of lamellar granules containing phospholipids, glycosphingolipids, and free sterols that are produced by keratinocytes. Essential fatty acids cannot be synthesized and, therefore, must be supplied in the diet. Animals are unable to change one series of fatty acids to another, eg, omega-3 to omega-6. Dermatologic signs of fatty acid deficiency include a thin and discolored haircoat, scaly skin, sebaceous gland hypertrophy with hyperkeratosis of the sebaceous ducts and increased sebum viscosity, increased epidermal turnover rate, weak cutaneous capillaries, and decreased wound healing.
The essential fatty acids most important for homeostasis of the skin in dogs and cats are linoleic acid and linolenic acid. Arachidonic acid is also an essential fatty acid in cats. Dihomo-?-linolenic acid (DGLA) and eicosapentaenoic acid can be synthesized from linoleic acid and linolenic acid, respectively. The skin is deficient in desaturase enzymes that insert double bonds into the fatty-acid chain; therefore, continual transport of unsaturated fatty acids from the liver to the skin is required for epidermal turnover. Because linoleic, ?-linolenic, and DGLA accumulate in the skin but cannot be converted to arachidonic acid at that site, these fatty acids compete with arachidonic acid for cyclooxygenase and lipoxygenase enzymes, which decreases production of inflammatory prostaglandins. Metabolites of DGLA (prostaglandin E1 and 15-hydroxy-8,11,13-eicosatetraenoic acid) and of eicosapentaenoic acid (leukotriene B5 and 15-hydroxyeicosapentaenoic acid) have anti-inflammatory and immunomodulatory effects.
In dogs with seborrhea, levels of linoleic acid in the skin are abnormally low, even though levels in the serum are normal. Oleic acid is believed to be substituted in skin when there is a relative deficiency of linoleic acid. Sunflower oil and safflower oil are good sources of linoleic acid and may be given at 1.5 mL/kg/day and 0.5 mL/kg/day, respectively. Concentrated fatty-acid supplements that contain eicosapentaenoic acid, ?-linolenic acid, decahexanoic acid, safflower oil, glycerin, and vitamin E have been effective in treatment of some seborrheic dogs.
Fatty acids are also beneficial in treatment of atopic disease. Atopic dogs have abnormal lipid absorption and metabolism. Although the benefits of fatty acids are clear, which combination of fatty acids is most effective and the most effective dose are not. Lack of response to one product does not preclude a favorable response to another product. Dosages several times those on the label may be required to control allergic pruritis. There are few side effects; however, pancreatitis has been rarely reported. Large doses may also cause weight gain or diarrhea.