@Cirion the omega 6 fatty acids are actually the precursors to the prostaglandins - it's hard to get more inflammatory then that. Not only do they cause and promote inflammation via multiple mechanisms- they are inflammation (basically).
But the effects of PUFA do damage far outside just causing inflammation.
1. They lower androgens and increase estrogen:
“Some of the interesting enzymes affected specifically by polyunsaturated fatty acids are those involved in hormone production. While they inhibit the formation of progesterone and androgens, they activate the synthesis of estrogen, which in turn activates the release of more free polyunsaturated fatty acids from the tissues, in a positive feedback pattern.”
2. They’re carcinogenic
“The equivalent of just about a teaspoonful of unsaturated fat per day is enough to show a threshold increase in the incidence of cancer. “
3. They’re immunosuppressive (omega 3s are actually more immunosuppressive then omega 6s and that’s the way omega 3s lower inflammation- via immunosuppression)
“The proteolytic enzymes are an essential part of innate immunity, and the highly unsaturated fatty acid, EPA, which is the most immunosuppressive of the fats, strongly inhibits proteolysis in some cells. The natural killer (NK) cells and phagocytic cells are two types of cell that are suppressed by PUFA, and they are involved in many kinds of physiological events, not just the killing of tumor cells and virus infected cells.
The immunosuppressive effects of PUFA are very general. Many metabolites that are known to have harmful effects on the immune system are increased by the PUFA (histamine [Masini, et al., 1990], serotonin, lactate, nitric oxide [Omura, et al., 2001]). These substances are also involved in tumor development.”
4. They’re prone to Lipid peroxidation - basically they go rancid inside your body. Yeah no fun.
5. They inhibit mitochondrial respiration:
“The suppressive effects of unsaturated fats on mitochondrial energy production have been widely investigated, since it is that effect that makes animal fattening with PUFA so economical. Rather than interpreting that as a toxic effect, using the innate structure and function of the mitochondrion as a point of reference from which to evaluate dietary components, the consumption of "good" oils is being used as the reference point from which to evaluate the meaning of metabolism ("efficiency is good," "low oxygen consumption is good")
6. They inhibit detoxification processes
“The inhibition of detoxification enzymes by PUFA (Tsoutsikos, et al., 2004) affects many processes, such as the elimination of estrogen, contributing to the positive feedback between estrogen and the oils. The meaning of this tends to be lost, because of the estrogen industry's effective campaigns.
7. They’re essential to the development of lipofuscin (age pigment- age spots)
8. They’re heptatotoxic (liver toxic)
9. They inhibit the formation of the protective Mead Acid (that’s the accurate way to see it in my opinion. I think its misrepresntitive to say that Mead Acid “fills in” for a lack of PUFA in the diet.)
10. They lower the ability to properly oxidize glucose.
“The most highly unsaturated fats found in fish oil break down into chemicals that block the use of glucose and oxygen.“
11. Lowers thyroid hormone production and blocks the effect of thyroid hormone.
“The unsaturation of vitamin A and of thyroxin allow them to bind firmly with transthyretin and certain other proteins, but the unsaturated fatty acids are able to displace them, with an efficiency that increases with the number of double bonds, from linoleic (with two double bonds) through DHA (with six double bonds). “
“While the competition by PUFA for protein binding sites blocks the effects of thyroid hormone and vitamin A, the action of PUFA on the sex steroid binding protein (SBP, or SSBG, for sex steroid binding globulin) increases the activity of estrogen.”
And I know I’m missing some other damaging effects of PUFA
(All quotes by ray peat)
One for the road:
“The food-derived polyunsaturated fatty acids play important roles in the development of all of the problems associated with aging--reduced immunity, insomnia, decreased learning ability, substitution of fat for muscle, susceptibility to tissue peroxidation and inflammation, growth of tumors, etc., and are probably involved in most other health problems, even in children. If research hadn't been guided by the economic interests of the seed oil industry, many of those problems would have been solved by now.“
Besides the ones @tankasnowgod referenced these are good too:
Fats, functions and malfunctions.
Suitable Fats, Unsuitable Fats: Issues in Nutrition
And Broda B from downtown with the game point:
“Everyone should have the privilege of playing Russian Roulette if desired, but it is only fair to have the warning that with the use of polyunsaturated fats the gun probably contains live ammunition.” - Dr Broda Barnes, MD
Great summary!