Omega 3 Fatty acids
“We need a diet that we can follow for life. An athlete who requires more calories and a pensioner enjoying retirement life are poles apart in their energy requirements, but both need a balanced intake of nutrients to remain healthy.”
There are no good or bad foods but only good or bad diets.
Dietary fats are the most concentrated source of calories. The role of fats in the diet has become much controversy in recent years. A high fat diet may lead to obesity because fatty foods are rich in calories. The human body can make most of the types of fats it needs from other fats or raw materials. The body needs at least 25g of fat a day to absorb fat soluble vitamins and also beta carotene from plant sources.
Fats are made up of fatty acids and they are of two main types- saturated and unsaturated. Omega-3 fatty acids are poly unsaturated essential fatty acids and they must be supplied by foods that contain them. Omega-3 fats are unique type of fats, delicate and susceptible to damage from oxygen-containing molecules. Omega-3 is derived from linolenic acid and is found in some vegetable oils such as soya bean and rapeseed oil, walnuts, flax seeds, flaxseed oil, leafy vegetables and in oily fish such as sardines, herrings, mackerel, and salmon.
They are needed in smaller amounts (about 1-2g per day) and can be obtained from a 100g portion of herring, one or two teaspoons of rapeseed oil or a handful of walnuts.
Omega-3 fats are classified as marine and plant omega-3 fats. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) come mainly from fish, so they are called marine omega-3s. Alpha-linolenic acid (ALA), the most common omega-3 fatty acid, is found in vegetable oils and nuts (especially walnuts), flax seeds and flaxseed oil, leafy vegetables, and some animal fat, especially in grass-fed animals. The human body generally uses ALA for energy, and conversion into EPA and DHA is very limited.
They are required as structural components of the brain and the retina of the eye during early development. They also bind to receptors in cells that regulate genetic function. They reduce inflammation and the tendency of the blood to clot and are also helpful in the treatment of heart disease, lupus, eczema, psoriasis and rheumatoid arthritis. They also play protective roles in cancer and other conditions. Omega-3 rich foods also help reduce triglycerides and LDL cholesterol.
The omega-3 polyunsaturated fatty acids of fish oil inhibit tumour growth in animals and also protect against colon cancer. High intake of fish oil may also protect against breast, bowel and pancreatic cancers which are associated with obesity and excessive fat intake. Omega-3 fatty acids are highly concentrated in the brain and are essential for cognitive (brain memory and performance) and behavioral function.
Low omega-3 fat levels will lead to attention deficit hyperactivity disorder (ADHD) and related behaviour or learning disabilities in children.
Omega-3 fatty acid deficiency leads to fatigue, poor memory, dry skin, heart problems, mood swings or depression, and poor circulation.
Omega-3 imbalance may also lead to hypertension, diabetes, obesity, and premature aging.
It is advisable to use liquid vegetable oils (rapeseed, sunflower, or olive oils) for cooking rather than hard fats. When eating meat, choose lean cuts and trim off the excess fat. It is much healthier to stew or grill rather than fry in extra fat.
Damage to the omega-3s in the food can be caused by light, oxygen, or heat. For this reason, foods that are rich in omega-3s should usually be stored in the refrigerator in a sealed container.
Diets rich in omega-3 fatty acids do not lead to toxicity. Omega-3s are rich in calories, and too much dietary fat can be associated with weight gain. However, intake of high-fat foods is restricted to foods that are rich in omega-3s as the excess calories can be burnt. Taking omega-3 fatty acid supplements may increase fasting blood sugar levels.
