Here is an extract from a long article laden with research data that runs through the history, corruption and propaganda that has been put out -- and is still being put out -- by sections of the US food vegetable oil industry as well as the FDA, concerning how healthy vegetable oils are for us in our diets. This extract, from a long article, is by Mrs Mary Enig, Phd, a famous researcher in nutrition. As Ted from Bangkok has already said, polyunsturated vegetable oils, whether chemically processed or not are simply not good for us. This extract also does not describe the effects of trans fats in margarine etc, but does describes the many other bad effects of especially rancid and oxidized vegetable oils:
Dangers of polyunsaturates(veg oils)
"The irony is that these trends have persisted concurrently with revelations about the dangers of polyunsaturates. Because polyunsaturates are highly subject to rancidity, they increase the bodyâ€TMs need for vitamin E and other antioxidants. Excess consumption of vegetable oils is especially damaging to the reproductive organs and the lungsâ€”both of which are sites for huge increases in cancer in the US. In test animals, diets high in polyunsaturates from vegetable oils inhibit the ability to learn, especially under conditions of stress; they are toxic to the liver; they compromise the integrity of the immune system; they depress the mental and physical growth of infants; they increase levels of uric acid in the blood; they cause abnormal fatty acid profiles in the adipose tissues; they have been linked to mental decline and chromosomal damage; they accelerate aging. Excess consumption of polyunsaturates is associated with increasing rates of cancer, heart disease and weight gain; excess use of commercial vegetable oils interferes with the production of prostaglandins leading to an array of complaints ranging from autoimmune disease to PMS. Disruption of prostaglandin production leads to an increased tendency to form blood clots, and hence myocardial infarction, which has reached epidemic levels in America.
Vegetable oils are more toxic when heated. One study reported that polyunsaturates turn to varnish in the intestines. A study by a plastic surgeon found that women who consumed mostly vegetable oils had far more wrinkles than those who used traditional animal fats. A 1994 study appearing in the Lancet showed that almost three quarters of the fat in artery clogs is unsaturated. The â€śartery cloggingâ€ť fats are not animal fats but vegetable oils.
Those who have most actively promoted the use of polyunsaturated vegetable oils as part of a Prudent Diet are well aware of their dangers. In 1971, William B. Kannel, former director of the Framingham study, warned against including too many polyunsaturates in the diet. A year earlier, Dr. William Connor of the American Heart Association issued a similar warning, and Frederick Stare reviewed an article which reported that the use of polyunsaturated oils caused an increase in breast tumors. And Kritchevsky, way back in 1969, discovered that the use of corn oil caused an increase in atherosclerosis.
Benefits of saturated fats
Foods containing trans fat sell because the American public is afraid of the alternativeâ€”saturated fats found in tallow, lard, butter, palm and coconut oil, fats traditionally used for frying and baking. Yet the scientific literature delineates a number of vital roles for dietary saturated fatsâ€”they enhance the immune system, are necessary for healthy bones, provide energy and structural integrity to the cells, protect the liver and enhance the bodyâ€TMs use of essential fatty acids. Stearic acid, found in beef tallow and butter, has cholesterol lowering properties and is a preferred food for the heart. As saturated fats are stable, they do not become rancid easily, do not call upon the bodyâ€TMs reserves of antioxidants, do not initiate cancer, do not irritate the artery walls.
Your body makes saturated fats, and your body makes cholesterolâ€”about 2000 mg per day. In general, cholesterol that the average American absorbs from food amounts to about 100 mg per day. So, in theory, even reducing animal foods to zero will result in a mere 5% decrease in the total amount of cholesterol available to the blood and tissues. In practice, such a diet is likely to deprive the body of the substrates it needs to manufacture enough of this vital substance; for cholesterol, like saturated fats, stands unfairly accused. It acts as a precursor to vital corticosteroids, hormones that help us deal with stress and protect the body against heart disease and cancer; and to the sex hormones like androgen, testosterone, estrogen and progesterone; it is a precursor to vitamin D, a vital fat-soluble vitamin needed for healthy bones and nervous system, proper growth, mineral metabolism, muscle tone, insulin production, reproduction and immune system function; it is the precursor to bile salts, which are vital for digestion and assimilation of fats in the diet. Recent research shows that cholesterol acts as an antioxidant. This is the likely explanation for the fact that cholesterol levels go up with age. As an antioxidant, cholesterol protects us against free radical damage that leads to heart disease and cancer. Cholesterol is the bodyâ€TMs repair substance, manufactured in large amounts when the arteries are irritated or weak. Blaming heart disease on high serum cholesterol levels is like blaming firemen who have come to put out a fire for starting the blaze.
Cholesterol is needed for proper function of serotonin receptors in the brain. Serotonin is the body's natural "feel-good" chemical. This explains why low cholesterol levels have been linked to aggressive and violent behavior, depression and suicidal tendencies. Motherâ€TMs milk is especially rich in cholesterol and contains a special enzyme that helps the baby utilize this nutrient. Babies and children need cholesterol-rich foods throughout their growing years to ensure proper development of the brain and nervous system. Dietary cholesterol plays an important role in maintaining the health of the intestinal wall, which is why low-cholesterol vegetarian diets can lead to leaky gut syndrome and other intestinal disorders.
Animal foods containing saturated fat and cholesterol provide vital nutrients necessary for growth, energy and protection from degenerative disease. Like sex, animal fats are necessary for reproduction. Humans are drawn to both by powerful instincts. Suppression of natural appetites leads to weird nocturnal habits, fantasies, fetishes, bingeing and splurging.
Source Article: coconutoil.com/oiling_america.
My own take on saturated fat intake is that since it is now all but impossible to guarantee that animal fats or meat sources used in our western diets like pork, beef and chicken can no longer be guaranteed to be grass fed, in their natural habitat and that their food and water comes from pollution free, unleached soils etc as was the case in the 19th century -- I would always therefore prefer virgin coconut oil as my favourite saturated oil source.