How Supplements Work
Essential Fatty Acids
Certain fats are as vital to us as vitamins. These are the fats known as Essential Fatty Acids, or EFAs. Popularly known as Omegas, these natural triglycerides are needed as building blocks for key body structures, including cell walls and connective tissue. These need to grow tight and strong so that, among other things, antigens can't get through to cause allergic reactions.
Because our bodies are not able to manufacture EFAs, we must get them in our diet. However, many people are confused about the issue of fats in the diet. We have been taught for decades that fats are "bad." Food manufacturers advertise "fat-free" foods. Health care providers do not remind us that certain essential fatty acids are required for optimum health. Most of us are starved for healthy fats.
Unfortunately, many of these healthy fats, or oils, in our foods have been partially or fully hydrogenated (saturated) to make cholesterol-free substitutes such as margarine, or used for deep-frying, which oxidizes and alters the fatty acids beyond the ability of our bodies to recognize and use them. The processing of commercial oil products has done much to eliminate a great deal of the natural health benefits of vegetable oils and is thought to be one of the leading factors in chronic inflammatory illness, including allergies and asthma, and cardiovascular disease. Peanut butter found in regular stores is an example of a hydrogenated food (you have to go to a health-food store to get the unhydrogenated kind) frequently fed to children, just another item contributing to their susceptibility to illness.
There are two types of essential fatty acids found in polyunsaturated fats, namely omega-3 (principally present in fish oils) and omega-6 (plant based fatty acids). They are absolutely required for human health as we cannot synthesize them in our own bodies. There are also other omegas found in foods and used by the body, but they are also formed by the body and therefore not classified as "essential."
Since we cannot synthesize essential fatty acids in our own bodies, we have to get them through our diet, whether from food or supplements. The reason they are called "essential" fatty acids is because they are essential to life; in other words, if we don't eat them, we die. It's that simple. And if we don't eat enough of them, we eventually get diseases. However, we must eat both omega-3s and omega-6s in the proper ratio, or we will still get disease.
For most of the time humans have been on earth we have eaten foods containing omega-6s and omega-3s in a ratio of about 2:1. However, over the last 50 years in North America, the ratio has changed to from 2:1 to 10-20:1. Our diet now includes huge amounts of oils that are extracted from plants and used for cooking or in prepared foods. These oils (such as corn oil, safflower oil, cottonseed oil, peanut oil, soybean oil) are primarily omega-6s. We have decreased our intake of omega-3s, found primarily in seafood, whole grains, beans and other seeds.
Eating too much omega-6 and too little omega-3 not only increases the risk for heart disease and certain other diseases, but also increases swelling to worsen arthritis and other conditions associated with the inflammatory response (such as allergies and asthma). A study of volunteers lacking the proper EFAs showed a decrease in their adrenal hormones, which directly affect the likelihood of asthma and allergies. (See the section What Happens In the Body?) To get your ratio of omega-6s to omega-3s back to a more healthful 2:1, eat seafood, whole grains, beans and other seeds. Taking Omega-3 capsules may also be of benefit. (You can order from a reputable company with outstanding prices by clicking on the Puritan's Pride logo on the left hand column.) Reduce your intake of foods made with or cooked in vegetable oils.
As well as taking EFA supplements, we can increase the efficiency with which our bodies use essential fatty acids by taking vitamin E, zinc, and the B vitamins. Another thing we can do is remove foods from our diet that can interfere with their processing. Saturated fats and partially or fully hydrogenated vegetable oils should be avoided. Sugar and alcohol also hamper the efficient metabolizing of fatty acids. 
When adding oils containing EFAs to the diet, remember that they lose much of their value when they're used for cooking. Heat destroys much of their fatty acid content or changes their chemical structure so that they are not recognized and used by the body, except as extra calories to add body fat. For this same reason, purchase only cold-pressed oils. Normally you find cold-pressed oils in health food stores. Read the label; if it's cold pressed it will say so. Oils sold in regular grocery store are usually heat-processed, but the label won't tell you that. Avoid heating and use the oils as salad dressing, on vegetables, or mix them into something.
Sources of omega-3: fresh (or frozen, not canned) fish, nut butters, particularly those made from walnuts and chestnuts, cold-pressed oils from flaxseed, borage seed, black currant seeds, evening primrose, and whole grains, especially wheat germ; sources for omega-6: borage seed, safflower, cottonseed, and peanut oils, avocado, and sunflower and sesame seeds. (Many of these foods have both omega-3, omega-6, and other omegas, in varying amounts and thus overlap as sources. Therefore, you may see different classifications in other publications from those I have here.)
Besides being used in the structure of cells, EFA's are important in the metabolism of cholesterol. When EFAs and the B vitamins choline and inositol are supplied, a very important nutrient, lecithin, can be made in the intestinal wall. Lecithin is a homogenizing agent which breaks fat and cholesterol into tiny particles. Each day our own liver manufactures over 3,000 milligrams of cholesterol. It is necessary for it to make this amount each and every day in order to provide the raw material from which vitamin D, the sex and adrenal hormones, and bile salts are made. It's very important to make sure you're getting enough EFAs rather than making sure you avoid eating wholesome foods which are sources of vital nutrients simply because they may contain some cholesterol.
For example, one of the best sources of lecithin is egg yolk---but maybe you don't think eggs are good for you because you've learned that they also contain cholesterol. Actually, while one egg contains about 200 milligrams of cholesterol, eating one only raises your blood cholesterol level by 3 milligrams. (See an analysis of 166 studies on the effects of dietary cholesterol.) The lecithin in the egg takes care of metabolizing the cholesterol in the egg. Lecithin is a powerful emulsifying agent which causes cholesterol and fats to be broken into microscopic particles which can be held in suspension, pass readily through arterial walls, and be utilized by the tissues. It also serves as structural material for every cell in the body, particularly those of the brain and nerves. And if it's indispensable to form each and every cell, just think think of the exceptionally high requirements of children, who are still growing!
And speaking of growing, here's a picture of my oldest grandson, who is growing like a weed. His mother used to take him and his brothers to the doctor all the time because they were sick all the time---ear infections, allergies, colds, coughs---you know the routine. Now she gives them supplements recommended by their chiropractor and she told me the other day that the kids are all much healthier.
Like cholesterol, lecithin is produced by the liver; it can also be made in the intestinal wall. However, it cannot be produced without EFAs and two of the B vitamins, choline and inositol, which are required for the very structure of lecithin, and numerous other nutrients to synthesize it. Because lecithin is essential to every cell in the body, the demands for these raw materials is tremendous and an undersupply of any one limits its production.
Since we need EFAs so desperately, it is imperative that they are absorbed by the body. However, fatty acids are insoluble in water and cannot be absorbed from the intestines without the action of bile salts on the fatty acids to enable them to be absorbed. In fact, carotene and vitamins A, D, E, and K also cannot be absorbed without adequate bile. When a diet is low in protein or high in refined carbohydrates, little bile can be produced. When this happens, digestion is incomplete and fat absorption markedly reduced. Part of the undigested fat combines with any calcium and iron in the food to form insoluble soaps; thus these minerals, as well as essential fatty acids, are prevented from reaching the blood. So in addition to food sources and supplements, we must also consider the health of the digestive system so that the food eaten and the supplements taken will be absorbed properly. If not, health will still not be built---allergies and asthma (and other diseases) will continue.