[Role and importance of dietary polyunsaturated fatty acids in the prevention and therapy of atherosclerosis].

INTRODUCTION Hyperlipoproteinemia is a key factor in development of atherosclerosis, whereas regression of atherosclerosis mostly depends on decreasing the plasma level of total and LDL-cholesterol. Many studies have reported the hypocholesterolemic effect of linolenic acid. TYPES OF POLYUNSATURATED FATTY ACIDS (PUFA) Linoleic and alpha-linolenic acids are essential fatty acids. The main sources of linoleic acid are vegetable seeds and of alpha-linolenic acid-green parts of plants. alpha-linolenic acid is converted to eicosapentaenoic and docosahexaenoic acid. Linoleic acid is converted into arachidonic acid competing with eicosapentaenoic acid in the starting point for synthesis of eicosanoids, which are strong regulators of cell functions and as such, very important in physiology and pathophysiology of cardiovascular system. Eicosanoids derived from eicosapentaneoic acid have different biological properties in regard to those derived from arachidonic acid, i.e. their global effects result in decreased vasoconstriction, platelet aggregation and leukocyte toxicity. ROLE AND SIGNIFICANT OF PUFA: The n-6 to n-3 ratio of polyunsaturated fatty acids in the food is very important, and an optimal ratio 4 to 1 in diet is a major issue. Traditional western diets present absolute or relative deficiency of n-3 polyunsaturated fatty acids, and a ratio 15-20 to 1. In our diet fish and fish oil are sources of eicosapentaenoic and docosahexaenoic acid. Refined and processed vegetable oils change the nature of polyunsaturated fatty acids and obtained derivates have atherogenic properties.