Seed oils were never a major part of the human diet until the early 20th Century when Proctor & Gamble introduced Crisco, a shortening made by bubbling hydrogen through Cotton Seed oil (introduced in 1911). This was a double whammy because not only was this a seed oil but the hydrogenation also produced “Trans fatty acids” which are toxic in their own right. Now it is estimated that Soybean oil accounts for about half of the worlds edible oil production. Were randomized trials comparing it to traditional oils like lard and tallow to see if it was safe done? NO!
All seed oils (Soy, Canola, Safflower, Corn, Cotton, walnut, pecan, almond to mention a few) contain primarily Omega-6 fatty acids and little to no Omega-3 fatty acids. For Instance 100 grams of almonds contain just 6 mg of Omega-3 fatty acid but contain 12065 mg of Omega-6 fatty acid while containing only 6 mg of Omega-3 .
Soybean oil is in an astonishing number of common products. Where is it? Almost all salad dressings, mayonnaise, peanut butter, ice cream, frozen dinners, and commercial baked goods. Just check the labels and get depressed.
Another substance produced when most vegetable oils are heated including Soybean Oil is “Toxic Aldehydes”. Here’s a nice article on how to avoid these. One of the Aldehydes produced is called ACROLEIN and was used as gas warfare during WWI. It has also been shown to be a mutagen and the poor workers at the many fast food restaurants around the nation are now exposed to it daily since the switch from saturated fats for deep frying. Yet no safety testing has been done.
And there are more problems with linoleic acid. In a trial published in the British Medical Journal called “The Sydney Study”, 458 men who had heart attacks were divided into 2 groups. One group ate a normal diet. The other group had almost all of their saturated fat replaced with linoleic acid and and they were followed for 7 years looking at recurrent heart disease and mortality. Here was the resulting statement “In this cohort, substituting dietary linoleic acid in place of saturated fats increased the rates of death from all causes, coronary heart disease, and cardiovascular disease. An updated meta-analysis of linoleic acid intervention trials showed no evidence of cardiovascular benefit.”
That’s why I, like so many of our hunter-gather ancestors prefer to eat a diet based on animal products. I don’t have to worry about “Seed Oils”!.