Omega-3 Fatty Acids Do Not Prevent Heart Disease

Discussion in 'Scientific Studies' started by DaveFoster, Nov 20, 2016.

  1. DaveFoster

    DaveFoster Member

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    The relation of lipid peroxidation processes with atherogenesis: a new theory on atherogenesis. - PubMed - NCBI

    "The extremely high sensitivity of polyunsaturated fatty acids (PUFAs) to oxygen is apparently used by nature to induce stepwise appropriate cell responses. It is hypothesized that any alteration in the cell membrane structure induces influx of Ca2+ ions. Ca2+ ions are required to activate degrading enzymes, such as phospholipases and lipoxygenases (LOX) that transform PUFAs bound to membrane phospholipids to lipidhydroperoxides (LOOHs). Enzymatic reduction products of LOOHs seem to serve as ligands of proteins, which induce gene activation to initiate a physiological response. Increasing external impact on cells is connected with deactivation of LOX, liberation of the iron ion in its active center followed by cleavage of LOOH molecules to LO * radicals. LO * radicals induce a second set of responses leading to generation of unsaturated aldehydic phospholipids and unsaturated epoxyhydroxy acids that contribute to induction of apoptosis. Finally peroxyl radicals are generated by attack of LO * radicals on phospholipids. The latter attack nearly all types of cell constituents: Amino- and hydroxyl groups are oxidized to carbonyl functions, sugars and proteins are cleaved, molecules containing double bonds such as unsaturated fatty acids or cholesterol suffer epoxidation. LOOH molecules and iron ions at the cell wall of an injured cell are in tight contact with phospholipids of neighboring cells and transfer to these reactive radicals. Thus, the damaging processes proceed and cause finally necrosis except the chain reaction is stopped by scavengers, such as glutathione. Consequently, PUFAs incorporated into phospholipids of the cell wall are apparently equally important for the fate of a single organism as the DNA in the nucleus for conservation of the species.

    This review intends to demonstrate the connection of cell alteration reactions with induction of lipid peroxidation (LPO) processes and their relation to inflammatory diseases, especially atherosclerosis and a possible involvement of food. Previously it was deduced that food rich in cholesterol and saturated fatty acids is atherogenic, while food rich in n-3 PUFAs was recognized to be protective against vascular diseases. These deductions are in contradiction to the fact that saturated fatty acids withstand oxidation while n-3 PUFAs are subjected to LPO like all other PUFAs. Considering the influence of minor food constituents a new theory about atherogenesis and the influence of n-3 PUFAs is represented that might resolve the contradictory results of feeding experiments and chemical experiences.

    Cholesterol-PUFA esters are minor constituents of mammalian derived food, but main components of low density lipoprotein (LDL). The PUFA part of these esters occasionally suffers oxidation by heating or storage of mammalian derived food. There are indications that these oxidized cholesterol esters are directly incorporated into lipoproteins and transferred via the LDL into endothelial cells where they induce damage and start the sequence of events outlined above. The deduction that consumption of n-3 PUFAs protects against vascular diseases is based on the observation that people living on a fish diet have a low incidence to be affected by vascular diseases.

    Fish are rich in n-3 PUFAs; thus, it was deduced that the protective properties of a fish diet are due to n-3 PUFAs. Fish, fish oils, and vegetables contain besides n-3 PUFAs as minor constituents furan fatty acids (F-acids). These are radical scavengers and are incorporated after consumption of these nutrients into human phospholipids, leading to the assumption that not n-3 PUFAs, but F-acids are responsible for the beneficial efficiency of a fish diet."

    Dairy fat contains furan fatty acids as well as fish: http://pubs.acs.org/doi/abs/10.1021/jf502975b
     
  2. Drareg

    Drareg Member

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    Nice find.
    Most of the fish oils are sold with extra vitamin E always good to remember that,do they ever acknowledged this when doing fish oil studies?
     
  3. Westside PUFAs

    Westside PUFAs Member

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    That isn't always true. Heat and certain processing can cause SFA oxidation.
     
  4. OP
    DaveFoster

    DaveFoster Member

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    @Drareg

    Very true; salmon especially.

    I think he was making a comparative statement in regard n-3 fatty acids, where the latter oxidize more readily, but you're correct.
     
  5. A.R

    A.R Member

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    What number heat temperature and processing would cause this?

    Thankyou
     
  6. amethyst

    amethyst Member

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    Very interesting. So Furan fatty acids are radical scavengers. Meaning they destroy free radicals that do cell damage in the body?
     
  7. Agent207

    Agent207 Member

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    Misleading title. Does somewhere in the text proves that affirmation? As far as I read this isn't even a study with conclusive result, just an assumption correlative based. It says the furan fatty acid may play a role in protection.

    That said, who cares? we don't eat omega3 or isolated chemicals in real life; we eat FOOD. That's what matters. And with or without the furan acids, the fact is that ABOVE ALL FISH CONSUMPTION LOOKS PROTECTIVE. That's the study main premise,

    "people living on a fish diet have a low incidence to be affected by vascular diseases"

    Whole food effects is what matters.
    Whole food =/ isolated compounds.
     
  8. OP
    DaveFoster

    DaveFoster Member

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    That's like saying "Who cares if PUFA is really bad? It's in all foods, and we eat FOOD!" Now, pass me that soybean oil. Soybean's a food.
     
  9. OP
    DaveFoster

    DaveFoster Member

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    Yes, and they at least seem to defend against linoleic acid.

    Antioxidant effect of naturally occurring furan fatty acids on oxidation of linoleic acid in aqueous dispersion

    "Naturally occurring furan fatty acids were synthesized and their antioxidant activity has been studied during the oxidation of linoleic acid in the phosphate buffer, pH 6.9, in the dark. The extent of the oxidation was followed both by the accumulation of conjugated diene and by the measurement of the residual amounts of linoleic acid. The tetra-alkylsubstituted furan fatty acids were found to suppress the oxidation. The trialkylsubstituted compound also showed antioxidant activity, being about 50% as effective as the tetra-alkylsubstituted ones. The di-alkylsubstituted one revealed no significant activity. The antioxidant activity of furan fatty acids depended on the number of substituents on the furan ring. Therefore, a tetra-alkylsubstituted furan ring may be necessary for the antioxidant action of furan fatty acids. The tetra-alkylsubstituted furan fatty acids reduced 1,1-diphenyl-2-picrylhydrazyl, reacted with the peroxyl radical generated from the thermal decomposition of a radical initiator, 2,2′-azobis(2-amidinopropane)hydrochloride (AAPH), and also suppressed the AAPH-induced oxidation of linoleic acid, indicating that, by scavenging, the peroxyl radical furan fatty acids inhibit the oxidation."
     
  10. Agent207

    Agent207 Member

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    You gotta be kidding. That's really what you got from the message??

    Your understanding skill looks sort of limited.
     
  11. OP
    DaveFoster

    DaveFoster Member

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    Firstly, people do take isolated omega-3's. They're known as fish oil, and they're prescribed for depression!

    You can't extrapolate effects from food without emulating the entire diet and background of the person; the latter's impossible.

    Just because someone on a predominantly fish diet lives longer doesn't mean fish is the source of that longevity. It could be the displacing of an alternative food that's causing a shorter lifespan.

    Also, there's fatty and non-fatty fish.

    Lastly, Eskimos had (and have I suppose) larger livers and could undergo more efficient ketogenesis than Europeans, and could theoretically deal with greater levels of toxic metabolic byproducts, but that means neither ketogenesis is optimal, nor that Europeans should emulate the diets of Eskimos.

    Additionally, stop being so trite in your response; there's no need for personal attacks.
     
  12. amethyst

    amethyst Member

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    Fish, that hasn't been contaminated heavily with mercury and other toxins is good to eat if you can find it. Not so sure about Japanese fish, due to the fallout from Fukushima. But mass produced fish oil is not so good. Food in it's natural state, is what humans ate for eons, and seems to be the better choice.
     
  13. Peater Piper

    Peater Piper Member

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    It turns out the Inuit weren't consuming a ketogenic diet. They probably weren't as healthy as we were led to believe, anyway, so kinda moot. I've come to think omega 3 is pretty benign (within a normal diet, no need to supplement), and some fish can be a net-positive, assuming it's an isocaloric diet in a normal to lean person. I've honestly gained nothing from restricting PUFA over the last three years from whole foods, and with less than 10% body fat I'd be surprised if I'm storing a lot of it.
     
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