Fat
It has almost become an accusation, hasn't it? - "Your dog is fat!", "Don't eat that - you'll get fat!"
Not so long ago, English was full of figures of speech linking fat to felicity, fortune or fame.
"Living off the fat of the land", "fat cats" or even, "the cream (fat) of society". Nowadays, it's fashionable to admire very slender people and to promote low-fat diets, but let's not throw out the baby with the bath water. Some fats are essential in the human diet, to support and maintain normal, glowing health. These are commonly called "essential fatty acids", or EFAs.
EFAs are fats which have crucial roles in human health but which cannot be made by the body. Therefore they must be eaten regularly. These are the so-called "good fats", as opposed to saturated and processed fats (the "bad fats").
There are two kinds of EFAs - omega-6 and omega-3. Omega-6 fatty acids are found in cold-pressed vegetable oils, nuts and seeds, e.g. evening primrose oil and sunflower seeds, and omega-3 fatty acids are found in oily fish, e.g. salmon and in flaxseed and walnut oil. The omega number refers to the chemical structure. Meat, dairy foods and coconut contain saturated fats. Olives and macadamia nuts contain mono-unsaturated fatty acids which, while they have their place, contain almost no EFAs.
Also, the omega-3 group is called the superpolyunsaturated family. This family contains short and longer chain fatty acid molecules. The shortest is alpha-linolenic acid (LNA), the next longest is eicosapentaenoic acid (EPA) and the longest is docosahexaenoic acid (DHA).
The omega-6 group is called the polyunsaturated family. This family contains linoleic acid (LA), gamma-linolenic acid (GLA) and arachidonic acid (AA).
Processed oils such as margarines and refined vegetable oils contain high levels of chemically altered trans fatty acids. While cold-pressed olive oil is suitable for cooking, never overheat EFA oils as this generates toxic free radicals in large quantities, greatly increasing the requirement for antioxidants to neutralise them. And as for frying - don't!
EFAs have a number of very important roles which include the formation and function of membranes, lipoproteins, lecithin and prostaglandins.
Membranes
Every cell in the body contains membranes - the cell wall, the intracellular machinery which carries out metabolism, the nuclear envelope, etc. The omega-6 EFAs compose a large part of the structure of these membranes, ensuring correct responses to hormones, co-ordination between the enzymes producing energy and heat, and effective barriers. Nerve cells are protected and insulated by myelin, specialised membranes which are high in EFAs.
Omega-6 fats are also needed to produce all new cells, including white blood cells for immune function. These cells together form the mucous membranes lining the blood vessels, airways and digestive tract, the hair, nails and skin as well as the tissues and organs of the body. The retina of the eye, along with the myelin of the brain, must also be supplied with omega-3 EFAs to function well. Thus for healthy vision, proper brain function and learning EFAs are needed.
Lipoproteins
Lipoproteins are tiny parcels of fat and cholesterol in the bloodstream which are wrapped in protein for safe transport around the body. The EFAs are crucial for regulating the levels of fats and cholesterol in the bloodstream.
Lecithin
In the liver, EFAs are incorporated into lecithin which transfers cholesterol into the bile for excretion. This is another very important function in keeping cholesterol levels healthy.
Prostaglandins
Both omega-6 and omega-3 EFAs are converted into prostaglandins - hormone-like chemicals which control body functions at the local level. These compounds are present very briefly and in microscopically tiny amounts, but are responsible for areas as diverse as co-ordination of healthy immune function, blood pressure, heart rhythm and blood clotting.
Some symptoms that Essential Fatty Acids may help:
Poor circulation - EFAs help maintain strong, elastic walls in the veins and arteries.
Allergic symptoms - weak membranes in the airways and the digestive tract can allow the entry of allergens and irritants, e.g. dusts and pollens. EFAs promote strong mucous membranes, as well as supporting a balanced immune response.
Fatigue - energy production in the mitochondria, the microscopic powerhouses in the cell, depends on intact healthy membranes to organise the enzyme chains.
Dry skin and hair - EFAs are essential for the growth of smooth, healthy skin, hair and fingernails.
PMT and period pain - prostaglandins profoundly influence the response of breasts, ovaries and uterus to the action of female hormones throughout the menstrual cycle.
Fluid retention - healthy kidney function depends on healthy membranes in the kidney tubules, which control water balance.
Dermatitis and eczema - as well as healthy skin tissue, EFAs maintain healthy immune activity, relieving the allergies which frequently provoke skin reactions.
Psoriasis - the skin symptoms are partly due to over-production of skin cells. Prostaglandins help to normalise the growth rate of skin.
Pain, swelling and stiffness of arthritis - prostaglandins balance the functions of the immune system, whose over-activity can provoke the pain and swelling of the joints. The omega-6 fatty acids help in repair of joint tissue, and the production of the synovial lubricant, which eases the stiffness.
Where to Find EFAs
EFAs are ideally found in healthy, natural foods.
Omega-6 fatty acids - in fresh, raw nuts, unprocessed peanut butter, sunflower and pumpkin seeds, soya lecithin, cold-pressed oils, e.g. soya bean, safflower, sunflower or evening primrose oil.
Omega-3 fatty acids - in oily fish (especially salmon, sardines, tuna and mullet), cold-pressed flaxseed (linseed) oil and in walnuts and hemp seed.
Supplements - especially of evening primrose oil, flaxseed oil and DHA derived from algae.
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