Only recently have we developed an understanding of the role of dietary fats in health. Fats are a source of energy (or calories too many in most cases) and provide structural protection around organs. As we'll see, they are also important components of cell membranes and precursors of important regulatory molecules.

Types of Fats
There are different kinds of fats, including animal fats, vegetable fats, saturated and unsaturated fats, liquid fats (oils) and solid fats. Some saturated fats have been artificially hydrogenated. This refers to the addition of hydrogen atoms to carbon atoms that are linked in a chain.

Fats that occur naturally as saturated fats and those that are artificially hydrogenated are solid at room temperature. The artificially saturated fats contain damaging substances called trans fats, which do not occur naturally. More about them later. Both animal fat and partially hydrogenated oils can increase inflammation and elevate the amount of cholesterol and fat in the blood. Vegetarian diets generally contain very little saturated fat, although coconut oil and palm oil are vegetarian sources of saturated fat, and some vegetarians do eat dairy products or eggs. (Vegans are strict vegetarians who eat no animal products.)

Essential Fatty Acids
Some unsaturated fats are required in the diet and are therefore called essential fatty acids or EFAs. These fats are essential for many reasons. They are an important component of cell membranes. These membranes allow passage of molecules in and out of cells and maintain receptors for hormones. Fats are also the building blocks for hormones. EFAs may also be converted into derivatives called prostaglandins, important hormone-like regulatory substances.

Good health is also dependent on a proper balance of the different types of fats. Linoleic acid is an omega-6 unsaturated fat, with its first double bond at the sixth position along the carbon chain. It is found in corn and beans. Linoleic acid is converted through a series of steps to a regulatory substance called prostaglandin E1. Prostaglandins regulate many metabolic functions. Minute amounts can cause significant changes in blood pressure, blood clotting, cholesterol levels, inflammatory responses, allergies, hormone activity, immune function, neurologic function and more. Prostaglandin E1 decreases the tendency of platelets to clump together, decreases inflammation, stabilizes blood sugar and decreases cholesterol. It decreases spasms in arterial and other involuntary muscle.

A deficiency of omega-6 EFA may result in eczema, premenstrual syndrome, breast pain and lumpiness, inflammation and autoimmune problems, hyperactivity in children and hypertension. Many people have adequate intake of these oils but inefficient conversion to the active prostaglandins. Specifically, individuals with a history of allergy, high cholesterol, diabetes, high alcohol intake, trans fat intake, chemical exposures, or specific nutrient deficiencies (particularly of magnesium and vitamin B6) may have difficulty with conversion. In these cases the metabolic block can be bypassed by taking supplements of GLA (gamma-linolenic acid), which helps the problems listed above.

The other EFA is called alpha-linolenic acid, which is an omega-3 oil. This oil is even more unsaturated (has more double bonds), with the first double bond at the third position in the carbon chain. This molecular structure gives the oil different properties. Omega-3 oils predominate in fish oils, flax seeds (linseeds) and some nuts, particularly walnuts. Omega-3 oils play a significant role in reducing the risk of coronary heart disease. Scientists have confirmed that populations with higher fish intake have a lower incidence of heart disease. These oils decrease the tendency of platelets to clump together, a reaction involved in the development of atherosclerosis as well as the precipitation of heart attacks. Omega-3 oils also decrease triglycerides, cholesterol and inflammatory reactions.

There is evidence that a deficiency of omega-3 oils is associated with various skin disorders, arthritis and joint stiffness, prostate problems, irritable bowel syndrome, premenstrual syndrome, depression, phobias and schizophrenia. These oils have a short shelf life, and they are generally removed from our food supply through processing for manufacturers' convenience. Deficiencies are therefore common.

Trans Fatty Acids
Let's get back to trans fatty acids. In their natural state, edible oils exist in a specific three-dimensional spatial configuration referred to as cis. When oils are highly processed during hydrogenation with heat and catalysts, they are partially converted to a different configuration called trans. These fatty acids do not participate in the normal pathways of fatty acid metabolism. They actually block the conversion of the natural cis fats to their active metabolites. Partially saturated or partly hydrogenated oil almost invariably contains trans fats. Oils that have been made into margarine contain significant amounts of trans fats, although food processors have made recent efforts to reduce the trans fat content of some margarines. Most processed foods and baked goods contain partially hydrogenated oils, and there is now a significant amount of these abnormal fats in the Western diet. These fats increase the risk of developing heart disease and cancer more than natural saturated fats. In addition, trans fats interfere with normal immune function.

It is important to have the right amount of EFAs in the diet or as supplements. Be sure that you use any oils sparingly, because they also lead to excess caloric intake and weight gain.

The metabolism and clinical use of the essential fatty acids has been one of the remarkable developments in medicine in the past decade. The education of physicians regarding these oils is due in part to the work of two physicians, David Horrobin, MD, and Donald Rudin, MD, who have done research and scoured the literature and reported on the physiology of fats and oils. A recent book, Fats That Heal, Fats That Kill, by Udo Erasmus, is a thorough review of fats and oils.

Many open-minded clinicians who have tried these essential fatty acid supplements have been impressed with the results in their patients, and they are now an important component of nutritional therapeutics. On the basis of the research and the teaching of these doctors, I tried these treatments in my practice and found them to be beneficial for a variety of clinical problems. They are safe, easy to take, and relatively inexpensive.

Essential Fatty Acid Supplements

EPA
EPA stands for eicosapentaenoic acid, so it is obvious why we call it simply EPA. This is a fish oil concentrate that is rich in omega-3 oil that has already started its conversion to prostaglandin E3. Fish oils also contain DHA (docosahexaenoic acid), another omega-3 essential fatty acid, which has similar properties.

Fish oil supplements have been shown to reduce inflammation, especially in arthritis, and to reduce rejection reactions after organ transplants, without the side effects of some of the anti- rejection drugs. They also lower cholesterol levels and reduce platelet stickiness. This reduces the risk of clots inside the blood vessels. They can help with some of the symptoms of premenstrual syndrome, bowel dysfunction and mental illness. Fish oil supplements can lower cholesterol levels in the blood, help to lower blood pressure, and reduce excessive blood clotting (platelet activity). It is helpful in heart and blood vessel disease.

How to take
The usual therapeutic dose of fish oils ranges from 3 to 12 g per day. Capsules of 1000 mg (containing 180 mg of EPA and 120 mg of DHA) are commonly available, and there are also some supplements with a higher concentration of the active oils. Sometimes higher doses are used in studies, but with comprehensive diet and supplement programs it is usually possible to achieve beneficial effects with lower doses. I usually recommend starting on two to four capsules per day, and may increase the dose if the response is not adequate.

Flax Seed Oil
Another good source of omega-3 oil is flax seeds. Many of the effects are similar to fish oil, but because they have not yet gone through the first step in conversion they may not be as helpful in some situations. Supplements of flax seed oil are useful in a variety of skin disorders, including psoriasis, and digestive problems, including spastic colon and probably inflammatory bowel disease. Some claims have been made for benefits in other inflammatory diseases, as well as cancer and immune system problems.

How to take
Usual doses of flax seed oil are 1-3 tbsp per day for therapeutic purposes, reducing this to 1-3 tsp after the desired effect is achieved. It is available in 8.8- and 17.6-ounce bottles. It is important that the processing of the oil is done in an inert gas environment and that the oil is stored in opaque bottles without oxygen. This oil is very easily oxidized especially if exposed to heat and light, and I recommend keeping it in the freezer until it is opened, and then in the refrigerator. (After taking it out of the freezer it will take a few minutes to liquefy.) It is a good idea never to cook with flax oil because of its sensitivity to heat, but you may safely add it to hot foods after cooking.

Flax seeds themselves are a good source of the omega-3 oil and a large amount of fiber, especially soluble fiber. Each tablespoon of seeds contains about one teaspoon of oil. The fiber in flax seeds is an effective treatment for both constipation and diarrhoea, and it helps to eliminate toxins. Grinding the seeds only for immediate use (in a small electric coffee mill) provides the freshest source of the oil. I like to grind up some flax seeds and add them to a blender drink with banana, other fruit, dilute juice and low-fat organic yogurt.

Gamma-Linolenic Acid (GLA)
Gamma-linolenic acid, or GLA, is found in evening primrose oil, borage oil and black currant oil. GLA is produced by enzyme action on the linoleic acid that is essential in the diet. It is the result of the first step in conversion to the beneficial prostaglandin PGE1, bypassing the metabolic blockages mentioned above. Supplements have anti-inflammatory effects because they lead to increased production of the PGE1.

Many studies have shown remarkable benefits from supplements of GLA. It helps relieve premenstrual symptoms, asthma and eczema and other autoimmune disorders. It can lower blood pressure in hypertension and decrease excessive blood clotting. It helps to regulate hormonal function through its effect on production and release of hormones and through control of hormone activity at the target organs. GLA has been shown to help in alcoholism, diabetes, acne, hyperactivity and numerous other conditions. Although it sounds miraculous, its effects are easily explainable based on well-known nutritional biochemistry.

How to take
I usually recommend the borage oil source of GLA, since it is the most cost effective and concentrated, meaning that fewer pills are necessary. It comes in 1000-mg capsules, which contain 240 mg of GLA. One per day is usually adequate. Evening primrose oil contains 40 mg of GLA per 500-mg capsule (usual dose--six per day); and black currant oil contains about 80 mg per capsule, and three per day is an adequate dose. After therapeutic results, the dose may be lowered for maintenance.