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Unsaturated oils

When an oil is saturated, that means that the molecule has all the hydrogen atoms it can hold. Unsaturation means that some hydrogen atoms have been removed, and this opens the structure of the molecule in a way that makes it susceptible to attack by free radicals.

8 passages
1 author
1997–2020
Most-cited: Ray Peat

Unsaturated oils are hazardous to health due to their ability to weaken the immune system's function, similar to the damage caused by radiation, hormone imbalance, cancer, aging, or viral infections . When an oil is saturated, it means that the molecule has all the hydrogen atoms it can hold, whereas unsaturation means that some hydrogen atoms have been removed, opening the structure of the molecule and making it susceptible to attack by free radicals .

The unsaturated oils, especially polyunsaturates, are liquid when cold, which is necessary for organisms living at low temperatures, but they easily get rancid when warm and exposed to oxygen . Seeds contain a small amount of vitamin E to delay rancidity, but when stored in human tissues, the oils are warmer and more directly exposed to oxygen, making their tendency to oxidize even greater .

Unsaturated oils cause hormonal imbalances, damage to the immune system, and oxidative damage . They interfere with the function of the thyroid gland, blocking thyroid hormone secretion, its movement in the circulatory system, and the response of tissues to the hormone . This can lead to increased levels of estrogen and a deficiency in the "protective hormones" progesterone and pregnenolone .

The thyroid hormone is required for using and eliminating cholesterol, so cholesterol is likely to be raised by anything that blocks the thyroid function . Unsaturated fats directly kill white blood cells, and vegetable oil emulsions were used to suppress the immune system in cancer patients . The same products are now marketed specifically for suppressing immunity in patients who have had organ transplants .

It has been shown that it is probably impossible to experience a detectable deficiency of linoleic acid outside of the laboratory setting, but the real issue is whether the amount in the normal diet is harmful to development . The unsaturated oils promote the formation of age pigment, and the discovery that stress or additional cortisone forces cells to take up more fat has implications for the effects of unsaturated oils on human development .

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