actually they don't need to be saturated. And unsaturated fats are much easier on your hear
Wrong. When you cut open those arterial plaques that kill people when they have heart attacks, they are comprised primarily of vegetable oils.
"Because polyunsaturates are highly subject to rancidity, they increase the body's need for vitamin E and other antioxidants. Excess consumption of vegetable oils is especially damaging to the reproductive organs and the lungsboth 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.41
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 "artery clogging" fats are not animal fats but vegetable oils.42
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.43"
http://www.westonaprice.org/know-your-fats/525-the-oiling-of-america.html#poly
I think it is great when people bring up the "conventional diet wisdom" as it gives me an opportunity to show the history of where these recommendations came from. It is fascinating how much was changed over the last 30-40 years due to nothing more than politics and a fraudulent study by Ancel Keys.
http://www.spacedoc.net/cholesterol_scam.html
It always boggles my mind how the American public (me included for many years) was bamboozled in to believing that the food we ate for millions of years is bad for us, but the new, highly processed items being passed of as food and created in factories is supposed to be the "healthy". All the while America, trying to follow the gvnmt recommendations, got sicker and fatter.