It has been shown through research that the ideal ratio of omega-6 fatty acids to omega-3 fatty acids in the human diet should be LESS THAN 4:1. Because vegetable oils are so high in omega-6 fatty acids and because processed, packaged foods are loaded with vegetable oils, the ratio of omega-6’s to omega-3’s in the western diet is an astonishing 15:1 in favor of the omega-6 fatty acids.
We are hearing more and more about avoiding things that cause inflammation in our bodies. Omega-6’s are the precursors to inflammatory compounds in the body and omega-3’s are the precursors to anti-inflammatory compounds in the body. Please get in the habit of reading ingredient labels. You will be astounded at the number of products that contain vegetable oils. Hence the reason for that high omega-6 to omega-3 ratio in the western diet.
Vegetable oils that are not real high in omega-6’s are olive oil, flaxseed oil and walnut oil. Olive oil is actually high in monounsaturated fatty acids which are considered to be healthy fats. This is why I recommend it for salads or sautéing when using low to moderate heat. So the 2 reasons to avoid most vegetable oils is that they are high in omega-6 fatty acids, (the precursors to inflammatory compounds in the body), and they degrade into harmful products when heated. Please see my posts from Nov. 13th, “The Problem With Peanut Oil”, and from Oct. 17th, “Frying and Sautéing in Vegetable Oils”.
Most of this information came from: THE GREAT CHOLESTEROL MYTH by Jonny Bowden, PhD and Stephen Sinatra, MD. This book also has a great visual chart to help you understand the differences between fatty acids (page 75).