The American diet provides too much saturated fat with its emphasis on meat. Saturated fat is not the only kind of bad fat.
Seeds, beans, nuts and kernels from various plants contain enormous amounts of energy stored as oil, starch or fat. Much of it is good until manipulated for human consumption.
The three macronutrients are stored in the endosperm and represent the sole energy and protein source for the developing embryo.
Nuts, seeds, and beans have their oils extracted, refined, filtered, mixed and packaged. The more refined and processed the oil, the more the oil cause metabolic stress.
Long chain fatty acids are the building blocks of the fats and oils consumed in the diet. The chains contain either 16 or 18 carbon atoms and may have one or more 'double bonds' along its length. The more double bonds a fatty acid contains, the more the fat can undergo molecular alteration.
Double bonds are the sites that free radicals attack. They are electron rich areas and are succeptible to these attacks.
Both linoleic and alpha-linolenic acid (ALA) are polyunsaturated fatty acids containing 18 carbon atoms.
Linoleic acid possesses two double bonds beginning at carbon number 6, while alpha-linolenic acid contains three double bonds beginning at carbon number 3.
Linoleic acid therefore belongs to the omega-6 family of polyunsaturated fatty acids while ALA belongs to the omega-3 family of fatty acids.
They are both considered essential fatty acids. That is only because the body cannot manufacture them. It does not mean they are equally beneficial or even desirable.
ALA, or omega-3 oils are good fats. The presence of too much omega 6 fatty acids in the diet makes it a bad fat.
Monounsaturated fats like olive, macadamia nut and canola oils contain oleic acid, an unsaturated fatty acid possessing one double bond at carbon number 9. These are termed omega-9 or simply monounsaturated fatty acids.
Polyunsaturated fat sources include soy, sunflower and fish oils. They are preferable to the saturated fats with one major reservation, intake of linoleic acid, the omega-6 essential polyunsaturated fatty acid must be limited. Its double bond at the number six position assures it of surviving the refining process better than its chemical cousin the omega 3 fat.
The double bond position is important because the 6 position better resists hydrogenation and chemical breakdown. This is in contrast to the exposed omega-3 bond, which becomes converted into less desirable oils in the refining process.
Linolenic acid (the omega-3 precursor) is readily converted to a trans-fatty acid when it is hydrogenated. Linolenic acid is destroyed in the commercial extraction process. Hence the complete lack of omega-3 oils in cooking oils.
Linoleic acid is found in high amounts in all vegetable oils including as safflower, soy and corn oils. When taken in amounts greater than ten percent of total calories, linoleic acid causes the oxidation of low-density lipoproteins. Modified lipoproteins are atherogenic and cause plaque deposits on the inside of arterial walls.
Linoleic acid, although an essential fatty acid, is implicated in initiating atherosclerosis and therefore its intake should be limited.
Polyunsaturated fats become rancid in the presence of oxygen, heat and light.
Omega-6 fats are converted to arachidonic acid, a precursor to the formation of inflammatory molecules.
When omega 6 oils are consumed in high amounts they change the healthy balance between omega-3 and omega 6 fats. The new ratio is an unhealthy one, an imbalance that promotes inflammation and arthritis.