Essential Fatty Acids

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posted by Basskiller:

Essential fatty acids (EFAs): are fats that are essential to the diet because the body cannot produce them. Essential fatty acids are extremely important nutrients for health. They are present in every healthy cell in the body, and are critical for the normal growth and functioning of the cells, muscles, nerves, and organs. EFAs are also used by the body to produce a class of hormone-like substances called prostaglandins, which are key to many important processes. Deficiencies of EFAs are linked to a variety of health problems, including major ones such as heart disease, cancer, and diabetes. It has been estimated that as high as 80% of the American population may consume insufficient quantities of EFAs.

Very few health issues have received as much attention during the past several decades as the question of fat in the diet. Sixty-eight percent of mortalities in America are related to fat consumption and diet, including heart disease (44% of deaths), cancer (22%) and diabetes (2%). There are several types of dietary fats. Saturated fat is found mainly in animal products, including meat and dairy products, and avocados, and nuts. Cholesterol is a dietary fat that is only found in animal products. Cholesterol is also made by the body in small amounts from saturated fats. Heavy consumption of saturated fat and cholesterol has been linked to heart disease and cancer. Unsaturated fats are typically oils from vegetables, nuts, and are present in some fish. These are considered the healthiest dietary fats. Essential fatty acids are unsaturated fats. EFAs are the only fats that may need to be increased in the American diet.

Scientists classify essential fatty acids into two types, omega 3 fatty acids and omega-6 fatty acids, depending on their chemical composition. Technically, the omega-3 fatty acids are alpha-linolenic acid, stearidonic acid, and two others called EPA and DHA. Alpha-linolenic acid is found mainly in flaxseed oil, canola oil, soybeans, walnuts, hemp seeds, and dark green leafy vegetables. Stearidonic acid is found in rarer types of seeds and nuts, including black currant seeds. EPA and DHA are present in cold-water fish, including salmon, trout, sardines, mackerel and cod. Cod liver oil is a popular nutritional supplement for omega-3 EFAs.

Omega-6 fatty acids are more common in the American diet than the omega-3 EFAs. These include linoleic acid, which is found in safflower, olive, almond, sunflower, hemp, soybean, walnut, pumpkin, sesame, and flaxseed oils. Gamma-linolenic acid (GLA) is found in some seeds and evening primrose oil. Arachidonic acid (AA) is present in meat and animal products.

Both types of EFAs, omega-3 and omega-6 fatty acids, are necessary in a healthy diet. Deficiencies of EFAs have been brought about by changes in diet and the modern processing of foods and oils. Many nutritionists believe that a major dietary problem is the use of hydrogenated oils, which are present in margarine and many processed foods. Hydrogenated oils are highly refined by industrial processes, and contain toxic by-products and trans-fatty acids. Trans-fatty acids are fat molecules with chemically altered structures, and are believed to have several detrimental effects on the body. Trans-fatty acids interfere with the absorption of healthy EFAs, and may contribute to atherosclerosis, or damage to the arteries. Deep-fried foods, which are cooked in oil that is altered by very high temperatures, also contain trans-fatty acids. Many health professionals, including those at the World Heath Organization, have protested against the use of hydrogenated oils in food and the consumption of trans-fatty acids. Health conditions linked to the consumption of trans-fatty acids and hydrogenated oils include cancer, heart disease, high cholesterol, diabetes, obesity, immune system disorders, decreased sperm counts, and infant development problems.

Dietary changes that have contributed to EFA deficiency or imbalances include the increased use of oils that contain few or no omega-3 EFAs; the industrial milling of flour that removes the EFA-containing germ; the increase of sugar and fried foods in the diet that may interfere with the body's absorption of EFAs; and the decreased consumption of fish.

A balance of omega-3 and omega-6 EFAs in the diet is recommended by experts. Americans typically consume higher quantities of omega-6 EFAs, because these are found in meat, animal products, and common cooking oils. Research has shown that too many omega-6 EFAs in the diet can lead to the imbalanced production of prostaglandins, which may contribute to health problems. Experts recommend that omega-3 and omega-6 EFAs be present in the diet in a ratio of around one to three. Americans consume a ratio as high as one to 40. Thus, the need for greater amounts of omega-3 EFAs in the diet has increased.

Symptoms of EFA deficiency or imbalance include dry or scaly skin, excessively dry hair, cracked fingernails, fatigue, weakness, frequent infections, allergies, mood disorders, hyperactivity, depression, memory and learning problems, slow wound healing, aching joints, poor digestion, high blood pressure, obesity, and high cholesterol.

General use
EFA supplementation is recommended for over 60 health conditions. EFAs are used therapeutically to treat and to prevent cardiovascular problems, including heart disease, high cholesterol, strokes, and high blood pressure. EFAs also have anti-inflammatory effects in the body, and are used in the nutritional treatment of arthritis, asthma, allergies, and skin conditions (e.g., eczema). EFAs are used as support for immune system disorders including AIDS, multiple sclerosis, lupus, and cancer.

Other conditions that may improve with EFA supplementation include acne and other skin problems, diabetes, depression, menopausal problems, nervous conditions, obesity, memory and learning disabilities, eye problems, and digestive disorders. EFAs are recommended for weight loss programs, as they may assist fat metabolism in the body. EFA supplementation is a recommended preventative practice, as well.

Preparations
Common EFA supplements are flaxseed oil, evening primrose oil, borage oil, black currant seed oil, hemp seed oil, and cod liver oil. Consumers should search for supplements that contain both omega-3 and omega-6 EFAs, because imbalances of EFAs may occur if either is taken in excess over long periods of time. Flaxseed oil is a recommended supplement, because it contains the highest percentage of omega-3 fatty acids with some omega-6 EFAs, as well. Flaxseed oil is generally the least expensive source of omega-3 EFAs as well, generally much cheaper than fish oil supplements. Evening primrose oil is a popular supplement as well, because the GLA it contains has shown benefits in treating premenstrual syndrome and other conditions. However, evening primrose oil contains no omega-3 EFAs. Hemp seed oil is a well-balanced source of both EFAs.

Supplements are available from health food stores in liquid and capsule form. The recommended daily dosage is one to two tablespoons (13-26 capsules), taken with meals. EFAs can also be obtained from a diet that includes cold-water fish consumed twice per week, whole grains, dark green leafy vegetables, walnuts, pumpkin seeds, wheat germ, soy products, canola oil, and other foods mentioned above. Whole flaxseeds are a wholesome source of EFAs as well, and can be freshly ground and added to salads and other dishes.

Precautions
EFA supplements are generally fragile products, and must be produced, packaged and handled properly. Consumers should search for quality EFA supplements produced by reputable manufacturers. Products that are organically grown and certified by a third party are recommended. EFA products should be produced by "cold or modified expeller pressing," which means that they were produced without damaging temperatures or pressure. Products should be packaged in light-resistant containers, because sunlight damages EFAs. Packages should include manufacturing and use-by dates on them, in order to assure freshness. Stores and consumers should keep EFA products under refrigeration, because heat damages them, as well. Taste can indicate the quality of EFA oils: those that have no flavor usually are overly refined, and those that taste bitter are old or spoiled. Because of their low temperature threshold, nearly all the oils that are used as EFA supplements are not suitable for use as cooking oils.

Side effects
Side effects with most EFA supplements are rare, because EFAs are nontoxic and are used by the body as energy when taken in excess. The exception is cod liver and fish oil supplements, which can cause vitamin A and D toxicity when taken in excess. Side effects of vitamin A and D toxicity include headaches, skin discoloration, fatigue, nausea, and gastrointestinal problems. Fish oil supplements that have vitamins A and D removed are available.

Interactions
To maximize the benefits of EFA supplements, several recommendations can be followed. EFA users should reduce the amount of fat, particularly saturated fat from animal products, in their diet. The American Heart Association recommends that a healthy diet contains 30% or less of its total calories from fat. For 2000 total calories per day, 600 calories or less should be from fat, including EFA supplements. Consumers should also completely eliminate hydrogenated and partially hydrogenated oils from their diets. This includes eliminating all processed foods that contain them, such as margarine and many packaged foods. Other foods that contain trans-fatty acids, such as deep fried foods, should also be eliminated. Recommended cooking oils are olive, safflower, canola, and sesame oils. EFA effectiveness may be increased by lowering the intake of sugar and alcohol in the diet. Nutrients that assist EFA uptake are the B-complex vitamins, vitamin C, zinc, and magnesium. As with any supplement, EFA effectiveness can be augmented with a nutritious, high fiber diet that emphasizes fresh and natural foods, and the intake of fish two times a week.

Key Terms
Atherosclerosis
Hardening of the arteries.
Cholesterol
A steroid fat found in animal foods that is also produced in the body for several important functions. Excess cholesterol intake is linked to many diseases.
Hydrogenated fat
An unsaturated fat, commonly vegetable oil, that is processed with high heat and hydrogen to make it solid at room temperature. Margarine is a common hydrogenated fat.
Trans-fatty acid
A toxic type of fat created by hydrogenating oils and by deep frying foods.

 

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Essential Fatty Acids -- The Key To Health,



Part I


Leo Galland M.D., F.A.C.N.
Director, Foundation for Integrated Medicine

(Author of Power Healing: Use The New Integrated Medicine to Heal Yourself, Random House, 1997)



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Although the body readily makes most of the fat that it needs from dietary starch or sugar, humans lack the ability to make essential fatty acids (EFAs) and must get them in food. EFAs are found in all foods but are most abundant in certain oils. They come in two distinct families, based upon their chemical structure. The two EFA families are not interchangeable and, in fact, tend to compete with one another in the body's metabolic pathways.
The larger family, called "omega-six" EFAs, are abundant in many vegetable seed oils, including corn, sunflower and safflower. Deficiency of omega-six EFAs causes impairment of growth and fertility, hormonal disturbances and immunologic abnormalities. An excess of omega-six EFAs may promote the development of cancer. People living in North America and Europe have relatively high levels of omega-six EFAs in their diets, because of the increasing consumption of vegetable oil during the twentieth century.

The smaller family, called "omega-three" EFAs, is most concentrated in fish oils and in flax seed (linseed) oil. It is also found in green leafy vegetables and in the flesh of animals that feed on grass and leaves. The human brain is rich in omega-three EFAs; their deficiency causes abnormalities in the development and function of the nervous system as well as immune defects. Omega-three EFAs formed an important part of the diet of Stone Age humans, who relied heavily on wild game and leafy plants for nourishment. Consumption of fish, flax seed meal and soy beans supplied omega-three's for our more recent ancestors. The past century has witnessed a systematic depletion of omega-three EFAs from the Western diet because of changes in food choice and in techniques of animal husbandry and food processing. Some theorists have traced the origins of numerous different diseases to a lifetime depletion of omega-three EFAs.

Extensive research published since 1985 has demonstrated that flax oil can prevent cancer and birth defects in animals. Fish oils, the other concentrated source of omega-three's, have made front page news because of their ability to prevent disorders as apparently unrelated to one another as cancer, heart attacks, migraine headaches, and premature births, and to reverse the effects of conditions as different as psoriasis, ulcerative colitis, rheumatoid arthritis and cystic fibrosis.

Some indications that an EFA deficiency or imbalance are present are: dry skin; the need to use moisturizing creams and lotions; "chicken skin", the presence of tiny rough bumps, usually on the back of the arms; dry or unruly hair; dandruff; soft, fraying or brittle nails; menstrual cramps; premenstrual breast tenderness. A person who has these symptoms will often find that they improve by supplementing an otherwise healthy diet with the appropriate oil. Discovering the appropriate oil requires a bit of personal experimentation. Most people in the United States and Europe are short on omega-three EFAs and will benefit from supplementing their meals with flax oil (one tablespoon a day). Flax oil should be stored in the dark and in the refrigerator; it should not be used for cooking.

Virtues of the GLA
Although most Americans consume more than enough of the omega-six EFAs, there is a small but significant proportion of the population (about fifteen per cent, if my patients are in any way representative), who are unable to properly metabolize omega-six EFAs and will benefit from supplementation with oils that are rich in omega-six's. The three most useful omega-six rich oils are evening primrose oil, borage oil and black currant seed oil, all of which are sold in capsule form. These oils contain a special EFA called gamma-linolenic acid (GLA), which allows the body to overcome the most common impediment to proper utilization of omega-six EFAs. Although experimental data indicate that feeding large doses of omega-six rich oils, such as corn oil or safflower oil, can promote the growth of cancer, there is no evidence that feeding GLA in the form of primrose oil contributes to cancer. Quite the contrary, primrose oil behaves like the omega-three rich oils (flaxseed and fish) in actually preventing tumor growth in experimental animals. The usual requirement for GLA among those who need it is supplied by taking four to six capsules of evening primrose oil, two to three capsules of borage oil, or three to four capsules of black currant seed oil every day (assuming each capsule contains five hundred milligrams of oil). I generally reserve GLA supplements for people whose dryness does not respond to omega-three supplementation. Because the omega-three and omega-six EFAs compete with one another in the body, feeding fish oil to a person who needs GLA may actually increase that person's omega-six deficit, making the skin dryer or the breasts more tender. An increase in these symptoms with omega-three supplements is almost surely a sign to switch to GLA. Lack of response is usually a reason to add GLA. Controlled studies have demonstrated therapenefits for GLA in people suffering from arthritis, eczema and premenstrual syndrome. What is important in making therapeutic decisions, however, is not the disease but the patient. EFA therapy does not treat disease, it improves cellular function.





Essential Fatty Acids -- The Key To Health,

Part II


Leo Galland M.D., F.A.C.N.
Director, Foundation for Integrated Medicine

(Author of Power Healing: Use The New Integrated Medicine to Heal Yourself, Random House, 1997)



--------------------------------------------------------------------------------

Balancing EFAs and Anti-Oxidants.
Because EFAs are polyunsaturated, containing two or more double chemical bonds, they are prone to rancidity, not merely in foods but also in the human body. Rancidity occurs when the double bond is broken by oxygen, producing an oxidized fatty acid. Oxidized fatty acids not only taste badly, they behave badly, disrupting the normal functioning of the cell membranes of which they are a part. Oxidized fatty acids are rapidly generated from the process called free radical-induced cell damage.
To protect EFAs from harmful oxidation, it is essential to consume adequate levels of dietary anti-oxidants, especially vitamin E. Consumption of a nutrient-dense diet will assure a higher-than-average intake of all anti-oxidants. Depend-ing upon the specific foods chosen, however, where those foods have been grown, the efficiency of digestion and absorption, the need for EFA supplementation, and the pres-ence of inflammation within the body, supplementation of the diet with additional anti-oxidants may be necessary. For people who supplement their diets with fish oils or flax oil, a minimum anti-oxidant supple-ment should include vitamin E (four hundred units per day), selenium (one hundred micrograms per day), and vitamin C (one thousand milli-grams per day), in addition to--not instead of--a nutrient-dense diet.

TRANS FATTY ACIDS AND HYDROGENATED OILS
The dangers of trans-fatty acids in the diet have recently received scientific attention that is long overdue. To understand the toxic potential of trans-fatty acids, you have to know how they effect the body's use of EFAs.

EFAs have a chemical structure which is polyunsaturated. Technically, this means that each molecule of an EFA has two or more double chemical bonds. The double bonding twists the mole-cule, giving it a serpentine shape. When incorporated into a cell's membranes, the snake-like EFA molecules add fluidity and flexibility to the membrane. EFAs, unfortunately, are rather unstable when exposed to air. The double bonds break down rapid-ly, producing a toxic form of fat that can be detected in food by its rancidity. Preservatives may be added to food to prevent this breakdown from occurring, thereby increasing the shelf-life of the food. A natural preservative for fatty acids is vitamin E (alpha-tocopherol), but the most commonly used preservatives are the synthetic anti-oxidants, BHT and BHA.

A more efficient way to prolong shelf-life, however, is to hydrogenate the fatty acids, destroying the EFAs. In hydrogena-tion, the double bonds are broken by hydrogen gas and the unsatu-rated fatty acids become saturated with hydrogen. This means that all sites for chemical bonding are filled. Natually saturated fatty acids are commonly consumed in meat and dairy products. They are also manufactured in your liver and stored in your body's fat cells. Saturated fatty acids are straight, not twist-ing, in shape, and impart stiffness and solidity to mem-branes. Human cell membranes usually have one saturated fatty acid lined up along-side one unsaturated fatty acid, producing just the right blend of stiff-ness and flexibility for responding properly to signals sent from other cells.

In present-day food processing, the hydrogenation of vegeta-ble oils is usually not complete. It is partial. Par-tially hydrogenated oils are easier to work with and produce a softer foodstuff than fully hydrogenated oils. Chemically, partial hydrogenation converts EFAs into trans-fatty acids, which are unsaturated fatty acids that twist abnormally. Trans-fatty acids do not have the serpentine shape and fluidity of naturally unsaturated fatty acids (which are called cis-fatty acids). Trans-fatty acids are stiff and straight, like saturated fatty acids, but, because they are unsaturated, they replace natural cis-fatty acids in the cell membranes. The result of trans-fatty acid consumption is stiff cell membranes, abnormal response to signals from other cells, and an increase in dietary requirements for EFAs. Partially hydrogenated vegetable oils, which are unbiquitous in manufactured foods, are loaded with these anti-nutrients.

In the first edition of Superimmunity for Kids, written ten years ago, I warned parents about the dangers of raising their children on margerine and other foods built from partially hydrogenated oils. My arguments derived from research on the chemical effects of trans-fatty acids and knowledge of how this chemistry could distort cell function. Clinical studies have vindicated the warning. High consumption of trans-fatty acids raises cholesterol levels and increases the risk of heart attack, especially among women. Dr. Walter Willett, chairman of the Department of Nutrition at Harvard University's School of Public Health, estimates that consumption of trans-fatty acids in the United States accounts for thirty thousand premature deaths per year. Hydrogenated vegetable oils containing trans-fatty acids have no place in a healthy diet and should be avoided by everyone.