Omega Fatty Acids : Nutritional Essence and Disease Prevention
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Omega Fatty Acids : Nutritional Essence and Disease Prevention

Kaynat  Khan profile Authored by Kaynat Khan on 14 Apr 2014 - 18:47.
 
omega-3-Fattyacids
Omega fatty acids are polyunsaturated fatty acids also known as essential fatty acids; they are part of all body cells needed for daily functioning (metabolism). As they cannot be synthesized by the body they must be supplied by the diet. The two nutritionally essential fatty acids include Omega -3 fatty acid or alpha linolenic acid and Omega-6 fatty acid or linoleic acid. Eicosapentaenoic acid and Docosahexaenoic acid are the other two nutritionally important Omega-3 fatty acids found as major components of retinal rod and cone cells and nerve synapses of brain.
A balance of essential fats (omega-3 and omega-6 fatty acids) is needed in the diet to maintain healthy blood clotting, blood circulation, cholesterol levels, inflammation, immune response and body's basal metabolism.
Role in Diseases:
  • Cardiovascular Diseases: Omega-3 fatty acids reduces platelet aggregation resulting in lowered risk of clotting and blockage of arteries that lead to cardiovascular disease or stroke. Studies have shown reduction in LDL cholesterol and triglyceride levels and increase in HDL cholesterol with n-3 fatty acid supplementation. They also help dilate blood thereby reducing the possibility of blood pressure.
     
  • Diabetes: The development of insulin resistance and type 2 diabetes mellitus is linked to a dietary fat profile high in saturated fats and deficient in essential fatty acids, especially Omega-3 fatty acids. Omega-3 fatty acids increase insulin sensitivity of muscle cells, they channelize the insulin towards glycogen storage of carbohydrates, rather than storing them as body fat.
     
  • Cancer: Omega-3 fatty acids may reduce colorectal and breast cancer risk by inhibiting tumor growth. In 2006, researchers reviewed 38 studies conducted over the past 40 years on the effects of omega-3 fatty acids and concluded that omega-3 supplements are unlikely to prevent cancer.
     
  • Rheumatoid Arthritis: Omega-3 fatty acids increase the cell membrane content of both EPA and DHA which increases production of anti-inflammatory group eicosanoids. Because of its anti inflammatory effect it reduces the symptoms of rheumatoid arthritis like joint pain and morning stiffness.They are also helpful in treatment of chronic allergic and inflammatory conditions like asthma and inflammatory bowel disease.
     
  • Neurological Disorders: Omega-3 fatty acids play an important role as structural membrane lipids in nerve tissue. The brain which is 60 percent fat, needs omega-3 fatty acids to function properly. There is some evidence suggesting that omega-3 fatty acids from fish oil and flaxseed may help combat both mild depression and attention deficit and hyperactivity disorder (ADHD).
  • Chronic Kidney Disease: Omega-3 polyunsaturated fatty acids decrease blood pressure, a known accelerant of kidney disease progression. However, the role of omega-3 polyunsaturated fatty acids in the treatment of kidney disease is not clear yet.
     
  • Osteoporosis: Diets high in omega 3 fatty acids (n-3 FAs) may be beneficial for skeletal health. There are different mechanisms by which dietary fatty acids affect bone: effect on calcium balance and osteoblast activity. Omega-3 fatty acid alone does not have significant results on osteoporosis, however if it is given in combination with calcium it enhances bone mineralization.
     
  • Anti-ageing effect: The major fatty acid of epidermis is arachidonic acid which is derived from omega-6 fatty acid. Omega-6 fatty acid helps in maintaining skin integrity and membrane stability.
      Dietary Sources:
  • Omega-6 fatty acid: Corn, cotton seed, safflower and soyabean oils.
  • Omega-3 fatty acid: fish oils, cod liver oil, oily fish like mackerel, herring, tuna, salmon, crab, shrimp, oyster, green leafy vegetables, flaxseeds, rape seed, chia seed, soyabean and walnuts.
  • Barley and oats contain appreciable amounts of gamma linolenic acid which lower cholesterol levels.
 
RDA: Recommended dietary allowances for essential fatty acids, suggested by ICMR (2010) are given below:

Group

EFA requirement % E*

Adults
Older Children
Young Children
Pregnant Women
Lactating Women

3

3

3

4.5

5.7

*Percentage total energy
WHO suggest that the ratio of omega-6:omega-3 should be 5 to 10:1 in the diet.
Essential fatty acids i.e. omega-3 (EPA and DHA) and omega-6 are nutritionally essential to the human body because of its role in reducing risk of many clinical conditions especially cardiovascular diseases and diabetes mellitus. It is advisable to consume dietary sources of these fatty acids rather than supplements, as supplements are a suitable alternative. As our diets have good amount of omega-6 fatty acid through oil, it is important to increase the amount of omega-3 sources in the diet to achieve the ratio and reap the nutritional benefits.
References: 
*Disclaimer: This is not medical advice. The content is for educational purposes only. Please contact your doctor for any health care issues.