Essential Fatty Acids
It is not just changes in our farming systems that have resulted in our bodies being nutrient deficient. We have changed what we eat. Our society now consumes more processed, junk food than ever before. Currently our fatty acid intake is out of balance.
The major components of all fats are the fatty acids. These might be saturated, monounsaturated or polyunsaturated. Saturated fats are usually derived from animal sources eg butter, lard. With the exception of palm and coconut fat which are highly saturated, most plant fats are high in either polyunsaturated or monounsaturated fats.
Saturated fats and monounsaturated fats are not necessary in our diet as our bodies can make them. But there are two polyunsaturated fatty acids that our body cannot make - linoleic acid and alpha-linolenic acid. These fatty acids must be included in the diet and are therefore known as 'essential fatty acids'.
Essential fatty acids are essential for the formation of healthy cell membranes, the proper development and functioning of the brain and nervous system. Our body can convert the linoleic and alpha-linolenic acid into longer chain fatty acids that serve as precursors for eicosanoids. Eicosanoids are hormone-like substances that regulate numerous body functions such as blood pressure, blood viscosity, vasoconstriction, and immune and inflammatory responses.
Eicosanoids can be produced from both omega 3 fatty acids and from omega 6 fatty acids, with opposing effects ie when made from omega 6 they have the potential to increase blood pressure, inflammation, platelet aggregation, thrombosis, allergic reaction and cell proliferation, whereas when formed from omega 3 they will have the opposite effect. Omega 3 and omega 6 fatty acids compete for enzymes in their desaturation, so excessive consumption of foods rich in omega 6 fatty acids may compromise the conversion of omega 3 fatty acids, with resultant health risks.
Scientists use the ratio of omega 6 fatty acids to omega 3 fatty acids to assess the balance between essential fatty acids in the diet. The recommended ratio is between 5:1 and 10:1, with some experts suggesting ratios of between 1:1 and 4:1 as being optimal. It is estimated that the ratio in the Western diet is between 14:1 and 20:1 with some studies indicating a higher ratio in vegetarians compared to omnivores. This is mostly because fish has a high omega 3 content (but only half as much as flaxseed oil), and because vegetarians tend to consume more vegetables, fruits, nuts, grains and seeds which are high in omega 6 fatty acids.
Current research suggests that the levels of essential fatty acids and the balance between them may play a critical role not only in growth and development, but also in the prevention and treatment of chronic diseases including coronary artery disease, hypertension, type II diabetes, arthritis and other immune / inflammatory disorders and cancer.
Omega 3s are used in the formation of cell walls, making them supple and flexible and improving circulation and oxygen uptake with proper red blood cell flexibility and function. Deficiencies in omega 3s are linked to decreased memory and mental abilities, tingling sensations of the nerves, poor vision, increased tendency to form blood clots, diminished immune function, hypertension, increased triglycerides and 'bad' cholesterol levels, learning disorders, menopausal discomfort and growth retardation in infants, children and pregnant women.