ABOUT EFA’S
1. Essential Fatty Acids
2. Prostaglandins
3. Lignans
4. Flax Seed Oil vs. Fish Oil
1. Essential Fatty Acids
Essential Fatty Acids (EFAs) are the building blocks of fats. There are two types: linoleic (omega-6) and alpha-linolenic (omega-3). They function as essential building blocks in every membrane of every cell in your body, keeping beneficial substances within your cells and harmful ones out. Because our bodies cannot make them, we have to obtain them from vegetable and fish sources, where they are naturally occurring.
The major functions of EFAs include:
a ready source of energy
insulation for your body against heat loss
prevention of your skin from drying or flaking
a cushion for your tissues and organs
production of “prostaglandin” families, hormones necessary for cell to cell biochemical functions such as energy metabolism, cardiovascular and immune system health
Both omega-3 and omega-6 EFAs are necessary in our diet, but must exist in the proper ratio. Today’s North American diet is sorely lacking in omega-3 EFAs. In the UK intake of omega-6 EFAs is much higher but mostly from refined and hydrogenated oils, and these have negative effects. Good quality omega-6 is available in fresh vegetables. The best omega-3 vegetable source is flax seeds. Moreover, the loss of a 1:1 ratio of omega-6:omega-3 EFAs is contrary to the diet of our ancestors when there was little evidence of chronic diseases. North Americans must therefore increase their omega- 3 EFAs consumption in order to right this ratio, which has seen it swing dramatically to 20-25:1 in favour of omega-6 EFAs.
Omega-3 intake can be beneficial for the following:
allergies
cardiovascular problems
cholesterol control
circulatory problems
eczema
eyesight problems
immune deficiencies
learning difficulties
nerve problems
osteoarthritis
rheumatoid arthritis
viral illness
weight management
Omega-6 intake can be beneficial for the following:
acne
allergies
cardiovascular problems
dehydration
dry skin
fatigue
food sensitivity
immune deficiencies
liver problems
mood swings
osteoarthritis
pre-menstrual syndrome
weight management
2. Prostaglandins
An excerpt from Tripping Down Prostaglandin’s Pathways, Price- Pottenger Nutrition Foundation Health Journal, Vol.2, No.3, Fall 1996. By Sally Fallon and Mary Enig, Ph.D.
Prostaglandins are a subset of a larger family of substances called eicosanoids. Eicosanoids are localized tissue hormones that seem to be the fundamental regulating molecules in most forms of life.
They do not travel in the blood like hormones, but are created in the cells to serve as catalysts for a large number of processes including the movement of calcium and other substances into and out of cells, dilation and contraction, inhibition and promotion of clotting, regulation of secretions including digestive juices and hormones, diuresis and salt retention, and control of fertility, cell division, cell division and growth.
Prostaglandins are produced in the cells by the action of enzymes on essential fatty acids. There are two prostaglandin pathways, one that begins with omega-6 linoleic acid and one that begins with omega-3 linolenic acid.
3. Lignans
Plant lignans belong to a highly potent anti-cancer phytochemical family. Lignans demonstrate a broad spectrum of biological activity including anti-tumour, anti-mitotic and anti-viral activities. When consumed, bacteria in our colon (microflora) converts plant lignans to mammalian lignans. Two of these – enterolactone and enterodiol – are now convincingly associated with low risk of breast and prostate cancers.
These hormone-like substances interfere with the actions of hormones such as eostrogen, making them anti-eostrogens. Most breast cancer and 30-50% of all colo-rectal cancer are now believed to be eostrogen dependent. Lignans are also aromatase inhibitors, which prevent the synthesis of eostrogen, and those which are involved in the propagation and proliferation of cancer cells.
The richest available source of plant lignans, by far, is found in flax seed fibre. Flax seed fibre consumption results in an average 100-800 fold greater total lignan production than the consumption of other oil seeds, cereals and legumes.
4. Flax Seed Oil vs. Fish Oil
Flax seed oil is the highest natural vegetable source of omega-3 EFAs with 57%; it also contains about 16% omega-6 EFAs. Although Flax seed oil and Fish oil stem from the same omega-3 EFA family, they behave quite differently in the human body. Flax seed oil contains Linolenic Acid (LNA), whereas fish oil contains Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA). EPA and DHA are derivatives of LNA.
The relationship between LNA and DHA/EPA is similar to that between beta carotene and vitamin A. Beta carotene is a precursor for vitamin A and is non-toxic even when taken in large amounts. When this happens, the only consequence is the appearance of a harmless orange colour in one’s skin pigmentation.
The body will store beta carotene until it is required, then convert it into vitamin A. When an individual takes in vitamin A the body is forced to use it in that form. Therefore when consumed in large quantities, vitamin A can become toxic1.
The body reacts in a similar manner to LNA and EPA/DHA. Even though the body can rapidly convert LNA to EPA and DHA (within 20 minutes), it only does so when needed. Ingestion of omega-3 in the form of EPA and DHA (fish oils) can have an almost drug-like action.
This is because it bypasses the body’s metabolic cycle and performs functions such as reducing platelet stickiness and increasing bleeding time with little metabolic control from the body, particularly when taken in large doses. An individual with a cut or wound who consumes large amounts of fish oil (DHA and EPA) can have problems with bleeding time, hence takes longer for his/her blood to clot.
Also, some studies show when fish oil is taken in conjunction with aspirin2 or by diabetics3 (who have a delicate balance to maintain), adverse effects can occur. On the other hand, flax seed oil omega-3 (LNA) exists in precursor form which the body can store until required. In other words, the body can control its utilization of LNA more easily than EPA/DHA.
That is why individuals who consume fish oil should consult their practitioner. Conversely, flax seed oil is safe even for babies (small doses in food)4. Flax seed oil is best taken in conjunction with food such as fresh garlic, onions, yogurt, quark, tofu or soy milk.
Advantages flax seed oil has over fish oil:
a more pleasant taste and smell
higher omega-3 concentration means lower processing costs
flax seed oil is less rancid
flax seed oil is not contaminated with chemicals, particularly if it is organic
there is no danger of overdosing from flax seed oil because it is not in pre-digested form