Nonsaturated fat acids differ on "saturation" degree: monononsaturated and polynonsaturated.
Polynonsaturated fat acids, such as , and which are a part of cellular membranes and other structural elements of fabrics and carry out in an organism a number of the important functions have special value, including provide normal growth and a metabolism, elasticity of vessels.
Polynonsaturated fat acids contain, basically, in vegetative fats and cannot be synthesised in an organism, therefore are irreplaceable. At their full absence in a food the termination of growth of a fruit is marked, permeability of small vessels changes.
Polynonsaturated fat acids, mainly and , serve as predecessors of gormono-like substances — , prevent cholesterol adjournment in walls of blood vessels.
, being a component of fats, also play the important role in a food. Being a part of cellular covers, they play an essential role for their permeability and a metabolism. In foodstuff basically there is a lecithin. Lecithin participates in regulation of a cholesteric exchange, prevents its accumulation in an organism, promotes deducing of cholesterol from an organism.
The greatest quantity contains in eggs (3,2—3,4 %), rather it is a lot of them in grains and beans (0,4—0,8 %), not refined vegetable oils (1,2—2 %). At refinement of vegetable oils the maintenance in them decreases at 6-10 time. Much contains in cheese (0,5—1,1 %), meat (0,8 %), a bird (0,5—2,5 %), a butter (0,3 0,4 %), fish (0,3-2,4 %), a potato (0,3 %).
In food contain also . In vegetative products it is most known , in animals — all known cholesterol.
is — it reduces level of cholesterol by formation with it of insoluble complexes that reduces level cholesterol in a digestive path, promotes its deducing and decrease in its level in blood.
Cholesterol plays the important role in an organism: is a structural component of all cages and fabrics, participates in an exchange of bilious acids, of some hormones, vitamin D (which part is formed in a skin under the influence of ultra-violet beams of cholesterol). However at increase of level of cholesterol in blood danger of occurrence and atherosclerosis development raises.
The basic part of cholesterol (about 70 80 %) in an organism is formed in a liver, and also in other fabrics of fat acids, mainly from sated, and carbohydrates. Most of all cholesterol the butter (0,17—0,27 %), a liver (0,13-0,27 %), kidneys (0,2-0,3 %) contains in such products, as eggs (0,57 %). In meat on the average contains 0,06—0,1 %, in fish — to 0,3 % of cholesterol.
Any of the fats, taken separately, cannot provide completely requirement of an organism for fatty substances. Animal fats, including dairy fat, possess high flavouring qualities, contain a lot of lecithin, vitamins A and D. However in them few irreplaceable polynonsaturated fat acids and are a lot of cholesterol. Vegetative fats contain many polynonsaturated fat acids, vitamin E, , promoting normalisation of a cholesteric exchange. However in vegetable oils there are no vitamins A and D.
Therefore animal and vegetative fats in food to use in a complex.
At a food of the pregnant woman should be present sufficient (but not superfluous) quantity of fats (25—30 % of a diet). The organism of the pregnant woman acquires the fats containing in milk and dairy products, and also in vegetable oils is better. However consumption and these fats should be limited, and it is expedient to exclude margarine, and also the beef, pork and mutton fat, fat from a diet. The requirement for fats makes 80—100 a day, on a share of vegetative fats should 20—30 From fats the butter and vegetable oils (sunflower, soya, corn) are recommended.