Since long plant fats are considered by nutritionists, dieticians and doctors, as main source of essential unsaturated fatty acids) n-6 and n-3 in human diet. On the market there is plenty of oils that can be consumed directly or used to frying. Last four decades consumption of oils increased several times due to stimulated by advertisement popularization of their pro-health activity. Plant oils supply mostly multi unsaturated fatty acids n-6 excess of which disadvantageously influence human health. Determinations of changes of oxidative stability of plant fats (during processing and storage) proved that consumption of oxidation products of fatty acids and sterols may be a reason of various diseases. Both epidemiologic and clinic studies indicated that if plant fats (both oils except this from olives and margarines) have possessed pro-health properties, their several times increased consumption would liquidate the problem of arteriosclerosis and its clinical complications (heart attack, stroke). For the present, every second death in the industrial countries results from the cardiovascular disease. Morbidity of cancer is also increasing and of neurological and neurodegenerative diseases is growing up vigorously.