Polyunsaturated fatty acids contain n3 and n6 fatty acids including the essential fatty acids (EFA) as the body cannot synthesize it. The only EFA in the n-6 series is linoleic acid and in the n-3 series is Alpha-linolenic acid, the most common Omega-3 fatty acid [2,3].
The remaining fatty acids in this category are not considered to be essential fatty acids.
The long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are found in a seafood only and can be synthesized from α-linolenic acid (ALA) but the conversion efficiency is low .
As per the World Health Organization guidelines, Polyunsaturated fats intake goals are set to be around 6 to 10 E% 1 to 2 E% for n-3 fatty acids and 5 to 8 E% for n-6 fatty acids where E % is the percentage of total dietary energy (E%) or as grams per day for adults .
Good plant sources of omega-3 fats include vegetable oils, such as soybean, safflower, canola, soybean, and corn oil; nuts such as walnuts; seeds such as flaxseeds; and some vegetables [1,4].
Also, replacing calories from carbohydrates with equivalent calories from monounsaturated fats can reduce mortality risk by 11% .
The n-6 fatty acids are almost completely absorbed .
Polyunsaturated fatty acids are oxidized to carbon dioxide and water  ].
Small amounts are lost via the sloughing of skin and other epithelial cells .