"Killer" fats are what we hear so much about recently, with large numbers of people wrongly turning to low fat diets. Little do they know, they are also decreasing their intake of the healing fats that are required for life. Improper low fat diets, useful for atherosclerosis, can kill you over the long term. Children are especially vulnerable to damage from low fat diets. To balance the one sided view on fats, we must talk about essential fatty acids (EFAs): an adequate supply of healing fats is even more important to health than the avoidance of supposed killer fats. Like vitamins, EFAs are essential to health. Older literature refers to them collectively as vitamin F. Vitamins and EFAs are essential for the following reasons:

• We must have them to live and to be healthy
• Our bodies cannot make them from other substances
• We must obtain an adequate supply from external sources, from food or from supplements
• Deficiency results in gradual deterioration of cells and tissues, and ultimately, in death
• Increasing the intake to adequate levels reverses the signs brought about by deficiency.

This definition of essentiality reflects the fact that essential nutrients perform key functions in our cells and tissues that the body cannot live without. EFAs play their essential roles by:

• Helping to form the membrane barrier that surrounds our cells and intracellular factories (organelles)
• Determining fluidity and chemical reactivity of membranes
• Increasing oxidation rate, metabolic rate, and energy levels
• Serving as starting material for hormone like regulating molecules (prostaglandins) that govern cell activities on a moment to moment basis

Special Properties Of EFAs
While EFAs are like vitamins in their essentiality, they differ in other respects. Vitamins are required in very small amounts (a few mg per day) whereas EFAs are macronutrients, necessary in grams per day. EFAs are perishable, deteriorating rapidly when exposed to light, air, heat and metals. Unlike vitamins, EFAs cannot be dried, powdered and stored for several years. EFA sensitivity makes careful processing and freshness extremely important.

Omega6 And Omega3 EFAs
Many standard texts on nutrition suggest three EFAs: linoleic, linolenic, and arachidonic acids. This outdated information is wrong. Two fatty acids are essential to human health. (Fish require only one fatty acid and plants require neither as they make their own.) The first is the omega6 EFA, which is called linoleic acid (LA). LA is abundant in polyunsaturated safflower, sunflower and corn oils. The second, known as the omega3 EFA, is called alpha linolenic acid (LNA) and is sometimes referred to as super unsaturated; it is found abundantly in flax and hemp seeds.

LA and its derivatives belong to the omega6 family of polyunsaturates. In addition to linoleic acid (LA), this family includes the down line metabolites gamma linoleic acid (GLA), dihomogamma linolenic acid (DGLA), and arachidonic acid (AA).

If LA is provided by foods, our cells make GLA, DGLA, and AA. Omega6 conversion can be inhibited by bad fats (margarines, shortenings, trans fatty acids, hard fats, sugar and cholesterol), lack of minerals (magnesium, selenium, zinc), vitamin deficiencies (B3, B6, C, E), viruses, obesity, diabetes, aging, and rare genetic mutations. In such situations, oil containing omega6 derivatives can help. GLA is present in evening primrose, borage, and black currant seed. DGLA is found in mother’s milk and AA in meats, eggs and dairy products.

LNA and its derivatives belong to an omega3 family of superunsaturates. Besides LNA, this family includes the down line metabolites eicosapentanoic acid (EPA), and docosahexanoic acid (DHA). If LNA is provided by foods, our cells make DHA and EPA. When the conversion of EFAs to their derivatives is inhibited by the factors listed above, DHA from black currant seed oil, or EPA and DHA from fish oils and northern ocean algae can be given.

A study on elderly Japanese patients demonstrated that blood levels of the omega3 fatty acids EPA and DHA increase after prolonged consumption of ALA from a plant based oil. The change is slow and requires about 10 months of supplementation. However, the result of the study suggests that supplementation with ALA from flax oil may to some degree have the same beneficial role as supplementation with fish oil. This news may be particularly interesting to people following a vegetarian diet or for those who do not eat fish products. [Journal of Nutrition Science Viturminol, December 1999]

Properties Of EFAs
The value of LA and LNA to health results from their chemical properties. EFAs react with oxygen: EFA rich oils such as flax, hemp and safflower were traditionally used in paints because they oxidize, dry and harden quickly when exposed to air. When fresh, these oils are valuable human foods. EFAs absorb sunlight, increasing their ability to react with oxygen by about 1000 fold and making them very active chemically.

EFA molecules carry slight negative charges that cause them to repel one another. They spread out in all directions. This property enables EFAs to carry oil soluble toxins from deep within the body to the skin surface for eliminations. EFAs form associations with the sulfhydryl group (cysteine) in proteins, important in reactions that make possible the one way movement of electrons and energy on which life depends. EFAs store electric charges that produce bioelectric currents important for muscle, cell membrane and nerve functions, including the transmission of messages.

EFA Functions
As structural components of membranes, EFAs help form a barrier that keeps foreign molecules, viruses, yeasts, fungi and bacteria outside of cells, and keeps the cells' proteins, enzymes, genetic material and organelles (small organs) inside. They also help regulate the traffic of substances in and out of our cells via protein channels, pumps and other mechanisms.
They perform similar functions in membranes that surround organelles within our cells. EFAs fulfill many functions:

• Regulate oxygen use, electron transport, and energy production, our cells’ most important moment to moment processes
• Help form red blood pigment (hemoglobin) from simpler substances
• Keep juice producing (exocrine) and hormone producing (endocrine) glands active
• Help make joint lubricants
• Are precursors of prostaglandins (PGs), three families of short lived, hormone like substances that regulate blood pressure, platelet stickiness and kidney function. A delicate balance between PGs with opposing functions, in part determined by omega6 and omega3 intake, determines the health of our cardiovascular system.
• Help transport cholesterol
• Help generate the electrical currents that make our heart beat in an orderly sequence
• Are precursors of derivatives such as DHA, which are needed by the most active tissues; brain, retina, adrenal glands and testes
• Help our immune system fight infections by enhancing peroxide production
• Help prevent the development of allergies.

EFAs play a role in every life process in our body and life without them is impossible. When consuming an EFA poor diet, expect a diversity of health problems.

EFA Requirements
Of approximately fifty known essential nutrients, LA has the highest daily requirement. The amount needed varies with season, latitude, levels of activity and stress, nutritional state, and individual differences. Just 1 to 2% of calories (1 tsp per day) prevent signs of deficiency in most healthy adults. LA optimums are around 3 to 6 percent of calories (1 tbsp per day), requiring about 30 IU of vitamin E to help prevent rancidity. Obese people and those eating hard fats, sugar, and trans fatty acids require more. Nutrients essential for LA functions include magnesium, selenium, zinc, and vitamins A, carotene, B3, B6, C and E.

An adult carries about 10 kilograms of body fat, of which approximately 1 kilogram is LA. Vegetarians’ bodies carry up to 25% of their body fat as LA. People with degenerative disease average only about 8% of their body fat as LA.

Alpha linolenic acid (LNA) optimums range between 1 to 2 tsp per day, averaging 2% of daily calories. Body content in healthy people is around 2% of fat, or half a pound of LNA. LNA requires the same antioxidants, minerals and vitamins necessary for LA functions.

Omega6 To Omega3 Ratio
Omega6 to omega3 ratios in healthy populations range from 1:2.5 (Inuit diets) to 6:1 (other traditional diets). Since 1850, omega3 consumption has decreased to one sixth its traditional level, resulting in an omega6 to omega3 ratio of 20:1 (contemporary polyunsaturated oil diets), which is associated with degenerative conditions. Flax, our richest source of omega3, quickly replenishes a long standing omega3 deficiency. 1 to 2 tbsp per day of good quality flax oil for a few months should suffice. Cold water fish (salmon, sardines, mackerel, herring) are a good source of the metabolites EPA and DHA.

Hemp seed oil has a remarkable fatty acid profile, being high in the desirable omega3s and also delivering some GLA, which is absent from the fats we normally eat. Hemp oil contains 57% linoleic and 19% linolenic acids, in the 3:1 ratio that matches our nutritional needs. Once difficult to find, many health food stores now routinely make hemp seed oil available as the demand for it has increased.

Long term exclusion of omega6 oils and excessive use of flax oil can result in a reverse imbalance of the one commonly seen, i.e. too much omega3. They should remain in balance. If a person has cancer, inflammatory conditions, or needs to lose weight, omega3 should be favored. The desried ratio in heart disease may be 1:1. Otherwise, an omega6 to omega3 ratio of between 2:1 and 3:1 is suitable for a healthy individual.

Mary Enig, PhD is a respected researcher in the field of fats and oils, especially the hydrogenated, partially hydrogenated and trans fats. The latest findings appear to implicate all seed oils in the promotion of cancer, heart disease, diabetes, obesity, allergies, adrenal failure and stroke. The list of implicated oils includes canola, soy, corn, safflower, sunflower and all hydrogenated and partially hydrogenated fats and oils. If this turns out to be true, then limiting the intake of the omega6 EFAs becomes increasingly important.

Dark meat fish like mackerel, salmon, sardines, bluefish, and swordfish contain the most concentrated sources of Omega3s, with an average of 1510mg of omega3s per serving. Most other fish, including canned tuna, provide about 450mg per serving, while shrimp, lobster and scallops contain about 320mg per serving. Krill are also becoming available as an excellent source of Omega3 fatty acids.

Processing EFAs
In nature’s package, EFA rich oils keep for years without spoiling. Once out of that package, light, air and heat attack EFAs. Like perishable produce, EFA rich oils should be made with care and obtained fresh. Frying and deep frying destroy EFAs by the combined effects of light, oxygen and heat, producing toxic substances that can lead to atherosclerosis and cancer.

EFA rich oils should be made and packaged in the absence of light, oxygen and heat. Frozen solid, oils remain unspoiled for a long time because freezing does not damage them. Manufacturers should ship them directly to retailers or consumers without stops along the way. You are probably better off using flax seeds and grinding them in a small coffee grinder just before use. They can be sprinkled on many different foods, will tend to be less rancid and also contain lignins. However, the most effective way of getting EPA and DHA into your body is through the use of a fish oil like cod liver oil.