The role of fat in the body PART 2
Polyunsaturated fatty acids from cheap oils are incorporated in cell membranes, altering their physical and functional properties diminishing the ability of cells which provides immunity to fight against cancer cells.
Lately, fat fish is very has a lot of ads, which contain polyunsaturated omega-3 fatty acid, alpha-linoleic, and generally essential fatty acids that can not be synthesized by the human body. But the body needs of essential acids are very small, and should not exceed 1% of the total energy intake.
At the Academic Medical Centre of the Amsterdam University, had been researched the the effect of polyunsaturated fatty acids in fish oil on tumor development. It was found that after a fed with fish oil for three weeks the number of liver tumors in rats was ten times higher, and the volume of metastases a thousand times greater than in animals fed with a low fat diet. On rats in whose food has been added saffron oil, which contains a large amount of unsaturated fatty acids, like the sunflower oil, the number of tumors was four times higher, and the volume of metastases 500 times higher than in animals fed with a diet low in fat.
Among the arguments in favor of fish oil or fatty fish consumption, it remembers that eskimos presents a lower number of myocardial infarction, which is true. But it goes over the large number of cerebral hemorrhage and that eskimos have the most cases of osteoporosis, although they ingest daily between 200 and 400 g fish protein.
Also true is that fish oil lowers the plasma triglycerides, but it glosses over the fact that docosahexaenoic acid (DHA, 22: 6n-3), found in a large proportion in this oil, it is very susceptible to peroxidation due to its high degree of unsaturation. After the consumption of omega-3 fatty acids, increases the unsaturation of fatty acids from cell membranes, due to the incorporation of these acids. By peroxidation is meant the poor oxidation of fatty acids. In case of energy oxidation, the chain double link breaks, forming fatty acids with lower molecule.
Finally, in the journal Atherosclerosis from January 2001, Tohoku University Sendai, Japan, collaborators, show that in rats, omega-3 fatty acids decreased the blood triglycerides but led to a high peroxidation of phospholipid in cell membranes speeding up the process of atherosclerosis. So, instead of protect against atherosclerosis, omega-3 fatty acids favors this process, even if triglycerides are decreased.
- The third role of fatty acids is to be precursors of some biologically active metabolites: some polyunsaturated fatty acids with 20 carbon atoms can generate complete compounds with extremely important functions, as prostaglandins, thromboxanes and leukotrienes.
Even in very low concentrations, these compounds exert an extensive range of biological functions, for example, serve as hormones and intracellular signaling molecules.
Have been identified more than 100 different prostaglandin. They boosts or brakes elementary functions of the body, as temperature, blood clotting, dilation and blood vessel contraction, allergic reactions, membrane permeability, blood intraocular inflammation, production of steroid hormones, appetite, immune system function and lipid metabolism.
When prostaglandins are in a balanced proportion, then it makes a relaxation of arteries, reducing blood pressure; diminishing tumor formation and prevents platelets agglutination, reducing the risk of thrombus formation. If, however, there is an imbalance in the proportion of prostaglandins, then it obtains reverse effects. The undergo molecular changes that cheap oil suffer during the extraction and refining and then during the partial hydrogenation, to become margarine, can have a unfavorable effect on the report between different prostaglandins.
Leukotrienes are substances with an essential role in regulating the immune system in the producing of antibodies and participating in the destruction of viruses and cancer cells. For this reason, it is extremely important that leukotrienes be formed from fatty acids with normal configuration, CIS, not to endanger their functions.
- The fourth role of fatty acids is as carriers for fat-soluble vitamins A, D, E and K.
- Finally, fats are assigned a number of organoleptic properties, this is especially because we have accustomed to them. It is interesting, however, that researchers at the Department of Chemistry Food of the Chemistry Institute of Technology, Prague, Czech Republic, have shown that the various flavors and flavor active substances are slightly soluble in oil than in water. On the other hand, the oil can form a thin film on the surface shape of the mouth, preventing the substances contact (which give taste to food) with taste receptors. Czech authors’ conclusion is that oils and fats, including mayonnaise, influence the perception of tastes, flavors, not only by suppressing their intensity, but also by changing the balance between tastes.
I can assure you honestly that a vegetable soup, stew or a dish of vegetables, prepared without adding any oil or other fat, tastes excellent. In the serving moment, you can add some soy milk yogurt or a mixer cream made from sunflower seeds, nuts or other seeds.
Once, Mark Twain said that everything you need in life are ignorance and confidence – ignorance and guts. These Twain’s words always obsesses me when I read, even in health magazines, various food recipes, of which is not missing frying or hardening some components in fat, whatever the source, or preparation of fat food in the oven.