Essential fatty acids and their usefulness
The essential fatty acids like omega-6 and omega-3 are indispensable for the normal development of the body. Unfortunately, the body cannot manufacture them and they have to be supplied through dietary sources.
Omega-3 fatty acids-
Omega-3 fatty acids can be obtained from vegetable oils like soybean oil, canola oil, olive oil, sunflower oil, nuts like walnut, hazel nuts, pecan nuts, flaxseed, and fishes such as trout, herring and salmon. Its other sources are eggs, meat and some green algae and sea weeds.
The common omega-3 fatty acids are hexadecatrienoic acid (HTA), alpha-linolenic acid (ALA), stearidonic acid (SDA), eicosatrienoic acid (ETE), eicosatetrienoic acid (ETA), heneicosapentaenoic acid (HPA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), tetracosapentaenoic acid and nisinic acid.
Alpha-linolenic acid (ALA), the "parent" omega-3 fatty acid is found in flaxseeds, hempseeds, pumpkin seeds, walnuts, and dark green leafy vegetables. Flaxseed oil is the richest source, containing almost 60 percent alpha-linolenic acid. Other omega-3 fatty acids are derived from ALA.
Eicosapentaenoic (EPA) is a derivative of alpha-linolenic acid and is needed to make hormone like substances called prostaglandins, which are anti-inflammatory in nature. It is found in fish liver oil supplements and cold-water fish, such as salmon, trout, and tuna. Docosahexaenoic (DHA) is another derivative of alpha-linolenic acid which is necessary for proper brain and nervous system development and visual function. It is found in cold-water fish and fish liver oil supplements and is also available in vegetarian supplements made from micro-algae. DHA is most abundantly found in mammalian brain.
They have beneficial effects on cancer, cardiovascular diseases, inflammation, developmental disorders and psychiatric disorders.
Excess consumption of EPA, DHA more than 3 grams per day can result in the possibility of hemorrhagic stroke, bleeding from other sites, increase in LDL (bad cholesterol) level in blood and reduced glycemic control in diabetics.
Omega-6 fatty acids-
Omega-6 can be obtained from vegetable oils such as soybean oil, corn oil, and sunflower oil, eggs avocado, nuts cereals, whole wheat bread, pumpkin seeds, spirulina etc.
The common omega-6 fatty acids are linoleic acid (LA), gamma linoleic acid (GLA), eicosadienoic acid, arachidinic acid (AA), docosadienoic acid, adrenic acid, docosapentaenoic acid, tetracosatetranoic acid, tetracosapentaenoic acid, calendic acid and dihomo-gama-linoleic acid (DGLA).
Linoleic acid (LA) is the "parent" omega-6 fatty acid. It makes primarily pro-inflammatory prostaglandins but also some anti-inflammatory prostaglandins. LA is found in high amounts in vegetable oils and in small amounts in most plant foods, such as sesame seeds, pumpkin seeds and many nuts. Gamma-linolenic acid (GLA) is a derivative of linoleic acid. It makes more anti-inflammatory prostaglandins than pro-inflammatory prostaglandins. It is found in evening primrose oil, borage oil and black currant oil. Other omega-6 fatty acids are derived from LA.
They are quite beneficial for the body and help to relieve the important conditions like diabetic neuropathy, rheumatoid Arthritis, allergies, attention deficit hyperactivity disorder (ADHD), breast cancer, hypertension, eczema, menopausal symptoms, osteoporosis, multiple sclerosis.
A high consumption of most vegetable oils may increase the likelihood of breast cancer in post menopausal women due to omega-6 fatty acids in them. Similar effects are observed in prostate cancer. A high consumption of vegetable oils may also cause inflammation in the body.
Importance of omega-6 to omega-3 fatty acids ratio-
An imbalance in the ratio of omega-6 to omega-3 fatty acids can be detrimental to the health. A very high omegs-6 to omegs-3 ratio promotes the pathogenesis of many diseases like cardiovascular disease, cancer, inflammatory and auto-immune diseases whereas a low ratio exerts suppressive effect. A ratio of 2:3.5 of omega-6 to omega-3 suppresses inflammation in rheumatoid arthritis patients and a ratio of 5:1 has a beneficial effect in asthma patients. A ratio of 10:1 has adverse consequences. Therefore, their optimal ratio may vary from disease to disease. As a matter of fact, a lower ratio of 2:1 of omega-6 to omega-3 is more desirable in reducing the risks of many chronic diseases but the ratio has increased to 10-20:1 due to our faulty dietary choices.
However, to get this healthful ratio of 2:1, we should eat fish, seafood, whole grains, beans and other seeds and reduce the intake of foods made with or cooked with vegetable oils from the seeds of corn, sunflower, safflower, cotton and soybeans. Fish oil supplements are a good source of useful omega-3 fatty acids.
An ideal diet, which maintains the balance between omega-6 and omega-3 fatty acids, is the Mediterranean diet. This diet emphasizes plant based foods like fruits and vegetables, whole grains, legumes and nuts. It replaces butter with healthy fats like olive oil and canola oil. Salt is used to a minimum just for taste; instead, herbs and spices are used. Red meat is limited to a few times a month, while fish should be consumed twice a week.