Contrary to popular myth, the body does need fat. It must be the right kind to do us good. People neglect to eat important, helpful foods because of their fat content. "Fat" is not an evil three letter word. Although the modern mantra is "The lower the fat, the better the diet", there are two basic flaws with this belief: first we have been led to believe all fats are bad. Reality is there are many diverse kinds of fat in foods, some are necessary, some are good. The second flaw is that we have been flooded with concepts of "low-fat" or "high-fat" diets. Nothing seems to be in between. Is it possible that Nature has created bad fats? Misconceptions about fat have caused many natural foods, that have been part of the human diet for millennia, to be considered bad for us.
To understand the bad reputation that fats have acquired, we must examine both the types of fats and their effects in our lives. Fat molecules are chains of various lengths with many atoms linked in a variety of ways. The way the atoms are linked makes the difference in their effects on our bodies. When all of the bonds in the fat are stable and no other atom can be inserted, the fat molecule is saturated. Saturated fats are usually a major part of the fat found in animal products. Some of these types of saturated fats can be harmful when taken in large amounts. These chains of saturated fat can change if one or two or three unsaturated bonds can be inserted along the chain. One inserted double bond makes the fat monounsaturated; more than one inserted double bond in the chain makes the chain polyunsaturated.
Monounsaturated fats have been a basic fat of healthy diets: diets of the Mediterranean, Greek, Middle East, and North Africa countries. These fats lower blood cholesterol and are not sensitive to oxygen damage. Polyunsaturated fats have many more unsaturated bonds. They are vital to health being the raw material for the metabolism of compounds in the body. Because these fats are very active in a chemical sense, they are very easily oxidized. Polyunsaturated fats need to be taken with compounds that combat oxidation effects such as vitamin E and many of the antioxidants in food. They are very safe if we eat them with plenty of antioxidant-rich vegetables and fruits: red, yellow, orange, green, and purple foods.
The special fats called essential fatty acids (EFA's) are in the necessary category and are polyunsaturated. Every living cell needs essential fatty acids. Skin, hair, joint, artery, heart, brain, glands, sperm, and nerve cells are dependent on having enough EFA's to keep them healthy. Since EFA's cannot be made by the body, yet are "essential" to overall health, they must be obtained through food or supplements. Populations consuming these fats have lower rates of heart disease, probably related to their power to prevent abnormal blood coagulation that leads to the formation of deadly blood clots in blood vessels.
How much fat should we eat? It's not at all clear what the optimal level of fat should be. What is clear is there is a wide range of fats. The amount of fat is closely linked to the type of fat being taken in, the rest of the diet, and to whether the fat is part of a whole food such as nuts, seeds, fish, oils, etc. When fat consumption is too low, the digestive system doesn't feel satisfied and sends signals to eat more food. Likewise, the digestive system feels satisfied with a reasonable fat intake and the signals are no more needed food. For most people, fat should not go below 25% of calories, and can increase to 35% if fat is from a plant-based diet.
Essential fatty acids (EFA's) are extraordinarily different fats. They are long carbon chains, some with unsaturated bonds, some with completely saturated bonds. The family is made up of three groups: omega-3 fatty acids, omega-6 fatty acids, and omega-9 fatty acids. By being mostly unsaturated, these fats remain fluid. ( For example, vegetable oils are unsaturated and fluid while butter is saturated and solid at room temperature.). As part of the cell membrane structure, EFA's form a kind of barrier preventing foreign and toxic material from entering cells while keeping nutrients and genetic material inside. A cell membrane is composed primarily of a two-layer construction. The outer layer is in contact with aqueous media around and within the cell; the inner layer has no contact with the fluid that surrounds it. This arrangement makes the cell membrane waterproof and unable to disintegrate into the fluid area while able to admit passage of both fat and water soluble molecules into the cells. If EFA's are deficient, destructive changes in the cell membranes can lead to poor metabolism and less energy on both the cell level and in the body in general.
An EFA deficiency is especially problematic for the brain. EFA's constitute one half of all brain tissue. So important are EFA's to the brain that they are allowed to cross the blood-brain-barrier. (BBB). The function of the BBB is to stop most chemicals from getting to the brain and harming it. But EFA's are so vital that the barrier allows them to penetrate the brain rapidly and become incorporated into brain fats.
Within the family, omega-3 is by far the most important member and the one most likely to be deficient in humans and dogs. Humans evolved on a diet that contained equal amounts of omega-3 and omega-6 fatty acids. About 100 years ago the food supply changed and began using hydrogenated (saturated) oils which reduced the oil's omega -3 content. At the same time, the domestic livestock industry began to use feed grains which are rich in omega-6 and low in omega-3 content. As a result our diets are now at a ratio of 20 to 25 parts of omega-6 to 1 part omega-3. The readings should be1:1. Our diets and those of our dogs are considered to be too high in omega-6 which may be a contributing factor in the rise of disease.
Commercially prepared dog food has a high grain content and saturated fat content from animal products and by-products. We can assume that the same problem exists: too little omega-3 and too much omega-6 by ratio.
Omega-3 is so much more important than the -6 or the -9 because it is both an anti-cancer agent and an anti- inflammatory agent. This EFA inhibits tumor cell proliferation by slowing or delaying the development of cancer metastases. There appears to be more than one way by which omega-3 may help to prevent initiation and progression of tumors. Omega-3 is cytoxic (deadly) to neoplastic (abnormal) cells. In other words, increasing the availability of the EFA will in turn increase cancer cell membrane fluidity, and excessive increases in fluidity can cause cell death. Omega-3 will also increase the capacity for drug (and nutrient) transport across the membrane. Studies show that when incorporating omega-3 into a chemotherapy program, the uptake and delivery of the chemotherapy agents is greatly increased into the abnormal cells.
On a day to day basis the EFA's have a broad effect. Being an anti-inflammatory is one of them. The mechanism of inflammation is the same for dogs as for humans. Let's look at inflammed arteries as an example. The first sign of inflammation begins when a type of white blood cell, a monocyte, sticks to the artery wall and then migrates to the wall's interior. Once monocytes enter the walls, smooth muscle cells release inflammatory chemicals called cytokines, a type of cell that eats fats and becomes characteristically foamy. The fat-filled, foamy cells cluster into fatty streaks in muscle and connective tissue cells. Over time, a substance known as "plaque" is created and hardening of the arteries begins. The body does not recognize plaque as bad. It's only doing its job, trying to heal the initial damage done to the blood vessel walls. It is a process that soon gets out of control and larger and larger deposits of plaque continue to be laid down, causing a barrier impeding blood flow. Next is the predictable heart attack or stroke. If the arteries don't choke your heart by cutting off blood supply then plaque will do it by becoming fragile and bursting or breaking off and making clots.
Omega-3 fatty acid can keep high levels of inflammation from developing and if there are problems with inflammation, can lessen the severity. Omega-3 is important in any course of treatment dealing with inflammation: heart disease, connective tissue problems, dysplasia, all types of arthritis, diabetes, as well as skin rashes and allergies. Omega-3 needs to be added to auto-immune conditions to reduce inflammation. Fish oils prove to be the best source of omega-3. In one European study, 11,000 people who suffered heart attacks participated in an EFA study where half received a daily dose of fish oil at 1000 mgs and the other half, a placebo. At the end of three months, more of those who took oil supplements were alive than those on the placebo. There was a 41 percent reduction in sudden death as well. At the end of three and half years, the group taking fish oils had a 45 percent fewer fatalities. The effect was probably due in part to omega-3's ability to consistently prevent platelet aggregation and altering cholesterol levels. Effective doses range all over the scale. In humans, 2-4 grams/day inhibits platelet aggregation; 4 grams suppresses inflammation; and 4 to 24 grams lowers plasma lipids. The effects become apparent within four weeks of administration. Dogs can use 1 gram/day regardless of size. However, a large dog could do better on 2 grams/day.
Omega-3 not one fat; it is a series. From canola and soybean oils we can obtain alpha- linolenic acid of omega-3; from walnut oil, we get the stearidonic acid of omega-3; and from cold-water, fatty fish we get eicosatetraenoic and eicosapentaenoic acids of omega-3. Of all these, the last two acids are the most important. Among their protective jobs are: scavanging free radicals; having an anti-cancer effect through inhibiting tumor cell access to blood circulation; inhibiting collagenases, a family of enzymes that eat up the collagen in connective tissue causing joint degradation; inhibiting plasmin, which degrades fibrin in blood and components of a cell's matrix. Fish oils in particular have the potential to inhibit cancer proliferation and progression through promoting cancer cell suicide (called apoptosis); moreover fish oils can induce the process of differentiation in cancer cells which is a reverting back to normal. Improved immune response and prolonged survival have also been documented in cancer patients supplemented with fish oils.
The omega-6 series comes from grains; it includes linolenic acids from most vegetable oils, nuts, and seeds; gamma-linolenic acids from evening primrose, borage, and black current seed oils; di-homo-gamma-linolenic acids from animal fat sources, dairy and eggs. Omega-6 is definitely beneficial when a person or dog is injured because of its clotting reactions and blood vessel constriction effects.
The last member of the series is omega-9 and currently the best known source is olive oil organically grown and cold-pressed. The oil can be drizzled on food a few times a week.
Because of the body's inability to make these nutrients on its own, they must be gotten from food and supplementation. Lack of EFA's may effect recovery from a serious illness especially cancer for without them the body cannot mount an effective immune response. The problem in maintaining optimum levels is that most diets lack EFA's through processing, and heating foods, and rancidity from long shelf life. Other losses come from drugs and elevated toxins in our air, water, and food. High temperatures such as frying destroy the EFA content in fish. Commercial food processing, whether for humans or pets, damages most EFA nutrients that may have been present. Processors often use hydrogenated oil (saturated solid fats) which when heated to a high temperatures, as they typically are during processing, convert to a "trans" fatty acid. These types of fat are used frequently for the deep-frying of fast foods and are also the types of fat used very widely in commercial bake products. These molecules have an unusual shape causing interference with normal cell processes. They both raise the LDL or bad cholesterol and reduce the HDL or good cholesterol. They raise blood triglyceride - a type of fat found in the blood vessels. They really are defective and cause this same defective condition in normal cells when they are substituted for healthy fatty acids ( the "cis" type). No other type of fat does this. Because trans fatty acids are hidden in the food supply, we can be misled thinking we are making a healthy choice.
Essential fatty acids must be accompanied by vitamin E to prevent an E deficiency, and in turn, E keeps these polyunsaturated fats from turning rancid in the body and becoming free radicals. EFA's need the help of other nutrients such as the presence of magnesium, selenium, and zinc, vitamins A, beta-carotene and the B's. When using fish for your source of omega-3, chose salmon, herring, bluefish, tuna, sardines, or mackeral which comes from the cleanest waters of the world to ensure non-contamination from mercury, PCB's, and other toxins. Buy the wild variety and not the farm raised fish which could be loaded with toxins from the food they are fed as well as the polluted water environment they are raised in. Make sure all EFA supplements are stored away from heat and light. You can freeze them if necessary though like all food sources, they're best fresh.
A deficiency of essential fatty acids shows up as increased allergies, dry hair and skin, brittle nails, acne, eczema, rashes, or tiny lumps on the skin. Any human or dog with arthritis, an auto-immune problem, cardiovascular disease, high cholesterol, cancer, fast aging, loss of mental faculties and alertness needs essential fatty acids. Any anti-inflammatory plan should incorporate lots of fruits and vegetables, fish 2 to 5 times a week, olive oil, seeds and nuts in the diet coupled with less animal protein, dairy, cheese and eggs. Supplements such as vitamin E, a B complex, essential fatty acids definitely help. These diet changes help reduce the risk of so many problems. Food is one of our most valuable tools for maintaining inflammation balance and health in general.
For supplies and further information consult Marie Cargill.