Fatty acids from plants are a class of compounds composed of carbon, hydrogen and oxygen, which are the main components of neutral fat, phospholipids and glycolipids. According to the length of the carbon chain in the molecular structure of fatty acids, they are divided into short chain fatty acids (less than 6 carbon atoms in the carbon chain), medium chain fatty acids (6-12 carbon atoms in the carbon chain) and long chain fatty acids (more than 12 carbon atoms in the carbon chain).

The fatty acids commonly found in vegetable fatty acids are long-chain fatty acids. According to the number of double bonds between carbon atoms in the carbon chain, fatty acids can be divided into monounsaturated fatty acids (containing one double bond), polyunsaturated fatty acids (containing more than one double bond) and saturated fatty acids (without double bond). Linoleic acid in essential fatty acids is the precursor of prostaglandin synthesis, and lack of EFA will lead to prostaglandin binding. The formation of animal spermatozoa is related to EFA. Lack of EFA for a long time can lead to infertility.

Fats rich in monounsaturated fatty acids and polyunsaturated fatty acids are liquid at room temperature, mostly vegetable oils, such as peanut oil, corn oil, soybean oil, rapeseed oil and so on. Fat composed mainly of saturated fatty acids is solid at room temperature, mostly animal fat, such as butter, lamb oil, lard and so on. There are exceptions, such as deep-sea fish oil, which is rich in polyunsaturated fatty acids, such as 20-carbon-5-oleic acid (EPA) and 22-carbon-6-oleic acid (DHA), although it is animal fat, and therefore is liquid at room temperature.

Fatty acids from plants are important components of tissue cells, which participate in the synthesis of phospholipids in mitochondria and cell membranes. EFA deficiency leads to mitochondrial swelling, changes in cell membrane structure and function, increased membrane permeability and brittleness psoriasis-like dermatitis, eczema and so on, which are closely related to lipid metabolism. About 70% of cholesterol in the body is esterified with fatty acids. In the absence of EFA, cholesterol transport disorders, deposition in the body lead to disease, EFA X-ray skin damage has a protective effect.