[Recent biochemical nutrition knowledge in relation to metabolism and the significance of essential fatty acids and n-3-fatty acids contained in fish].

A survey is given on some newer knowledge about metabolism and about the importance of the essential fatty acids and of the n-3 fatty acids (eicosapentaenic, docosapentaenic, docosahexaenic acids) which occur in fish oils. In the body the linoleic acid via intermediate steps can be transformed into the arachidonic acid, from which various prostaglandins and leucotriens as well as the thromboxane A2 can be formed. The transformation of the linolenic acid into the eicosapentaenic acid is slight in man. The docosahexaenic acid is necessary for the construction of phospholipids in the brain and in the retina. The uptake of fish fatty acids inhibits the formation of thromboxane A2 and of leukotriens from the arachidonic acid. The fish fatty acids further in the liver in the peroxisomas the activity of the enzymes for the beta-oxidation; the formation of lipoproteins of high density increases under their influence: the triacylglyceride content, the cholesterol as well as the lipoprotein content of very low and low density decreases, when there is an adequate part of fish fatty acids in the nutrition.