Vitamin F or Fatty Acids are the acids occurring in natural triglycerides and are monocarboxylic acids ranging in chain length from 4 to usually 24 carbon atoms. They are yielded by fats on hydrolysis along with glycerol. Fatty acids are divided into
- Saturated fatty acids such as lauric, palmitic and stearic acid
- Unsaturated fatty acids are further divvied into monosaturated and polyunsaturated fatty acids.
- Monounsaturated fatty acids: These fatty acids lower the total plasma cholesterol level but have no effect in high-density lipoprotein (HDL).
- Polyunsaturated fatty acids: The nutritionally important polyunsaturated fatty acids may either be omega-3 or omega-6 fatty acids. Both of them cause lowering of cholesterol level but omega 6 has the disadvantage of lowering HDL also.
The polyunsaturated fatty acids are mostly found in vegetable oils while the saturated ones are found in animal fats.
Essential fatty acid are those that cannot be synthesized in our body so they have to be derived only from the foods. They are the linoleic acid and the α-linolenic acid and these are polyunsaturated fatty acids. Arachidonic is semi-essential fatty acid. Among these most important essential fatty acid is the linoleic acid which serves as a basis for the production of other essential fatty acids.
- Linoleic Acid: It is abundantly found in vegetable oils such as corn oil, safflower oil, sunflower oil, soya bean oil, groundnut oil, sesame oil, mustard oil, coconut oil and palm oil.
- Arachidonic Acid: Its sources are meat, milk, and eggs.
- α-linolenic acid: Its sources are soya bean oil and leafy vegetables.
The polyunsaturated fatty acids, linoleic acid, and α-linolenic acid are required for a normal body functioning and also because these cannot be made in the body, therefore these two fatty acids are necessary dietary ingredients. They have many important properties in our body and these are as follow.
- These fatty acids are the important component of the phospholipids of the mitochondrial and cell membranes; they are found in high concentration in reproductive glands.
- A high concentration of linoleic acid occurs in cholesterol esters and this acid may have an important role in cholesterol transport.
- The ingestion of this essential fatty acid especially omega 3 type causes lowering of the plasma cholesterol level which is believed to protect the individual form of atherosclerosis.
- These three polyunsaturated essential fatty acids act as an immediate precursor of a very important group of compounds called eicosanoids. The eicosanoids include Prostaglandin. Prostacyclin, Leukotrienes, and Lipoxins.
A deficiency of these three fatty acids results in stunted growth in a variety of animal species. In young rats, scaliness of the skin with loss of hair and a decreased reproductive capacity are seen. Early death takes place. In a human being, deficient intakes of these acids have been seen to affect the infant as well as the adult. The symptoms of its deficiency include dry, scaly and thickened skin and impairment of growth.
Increase amount of fatty acid (vitamin F) results in cholesterol deposition in the arteries leading to their thickness and certain cardiovascular diseases.
It is recommended that approximately 5 grams of linoleic acid must be used daily.