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| This is a test thread. Those who believe the claim that some amount of dietary polyunsaturated fatty acids ("PUFAs") are essential for life and/or basic biological functions (in and adult, non-pregnant human) are asked to provide evidence for it here. |
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| The issue is still LDL oxidation, and so the less PUFAs the better, in general. I want my LDL it be at least on the high end of "normal," because low LDL means greater cancer risk (and other "diseases"). The reason they make these claims is because they are looking at statistical correlations, rather than trying to understand the issue comprehensively, including the molecular level (the molecular-level evidence shows that if LDL contains a lot of PUFAs, it's much more susceptible to oxidation). |
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| Did the study investigators not actually measure the results of the control/olive oil group? |
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| Which study are you referring to? |
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| The one that was just quoted in favour of DHA supplementation. I didn't read any results for the Olive Oil group. |
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| The results they gave seem to be compared to the oleic group, so there was 22 percent less small LDL in the DHA group as compare to the oleic group, right? Again, this is indirect "marker" stuff, and now it's known that the smaller the LDL the more susceptible it is to oxidation, so that is the key, and it's easy to prevent oxidation, but these "researchers" probably don't even know about the research on oxidized LDL. If they do, I would classify this "study" as academically dishonest or at least misleading. |
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On the www.raypeat.com there is an excellent essay on fish oil. Below is an excerpt from it:
QUOTE: ...The "prion" diseases, CJD and TSE/BSE (mad cow disease) have many features in common with Alzheimer's disease, and several studies have shown that the "prion" protein produces its damage by activating the lipases that release polyunsaturated fatty acids and produce lipid peroxides (Bate, et al., 2004, Stewart, et al., 2001).
Acrolein reacts with DNA, causing "genetic" damage, and also reacts with the lysine in proteins, for example contributing to the toxicity of oxidized low density lipoproteins (LDL), the proteins that carry cholesterol and that became famous because of their involvement in the development of atherosclerosis that was supposedly caused by eating saturated fats.
My newsletter on mad cow disease discussed the evidence incriminating the use of fish meal in animal feed, as a cause of the degenerative brain diseases, and earlier newsletters (glycemia, and glycation) discussed the reasons for thinking that inappropriate glycation of lysine groups in proteins, as a result of a lack of protective carbon dioxide/carbamino groups, produces the amyloid (or "prion") proteins that characterize the dementias. Acrolein, produced from the decomposing "fish oils" in the brain, is probably the most reactive product of lipid peroxidation in the brain, and so would be likely to cause the glycation of lysine in the plaque-forming proteins.
These toxic effects of acrolein in the brain are analogous to the multitude of toxic effects of the omega-3 fatty acids and their breakdown products in all of the other organs and tissues of the body. Cancer cells are unusual in their degree of resistance to the lethal actions of the lipid peroxides, but the inflammatory effects of the highly unsaturated fatty acids are now widely recognized to be essentially involved in the process of cancerization (my newsletters on cancer and leakiness discuss some of the ways the fats are involved in tumor development).
The fats that we synthesize from sugar, or coconut oil, or oleic acid, the omega-9 series, are protective against the inflammatory PUFA, in some cases more effective even than vitamin E... UNQUOTE.
Source: http://raypeat.com/articles/articles/fishoil.shtml |
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QUOTE: ...Results Changes in gene expression as observed in response to dietary oxidized cholesterol were strongly dependent on the type of fat. In the rats fed coconut oil, the expression of 7 genes (5 up�?and 2 down–regulated) was altered by dietary oxidized cholesterol, while in the rats fed salmon oil, the expression of 50 genes (16 up�?and 34 down–regulated) was altered. 29 genes (22 up- and 7 down–regulated) were identified as possible targets for an altered gene expression by dietary salmon oil as compared to dietary coconut oil.
Conclusion The present study showed that dietary oxidized cholesterol transcriptionally affects many genes involved in xenobiotic metabolism and stress response—an effect that was amplified by the administration of fish oil as dietary fat. UNQUOTE.
Source: European Journal of Nutrition, Volume 44, Number 4 / June, 2005.
On the internet: http://www.springerlink.com/content/7q1da2uxdfbtqagc/ |
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| This is nice. So the fish oil can actually impair the detoxification of oxidized cholesterol in the body. The experts usually teach that coconut oil + cholesterol is the prescription for atherosclerosis which is "prevented" by fish oil ... Even without any studies I feel much better on coconut than the fish oil. Also I have a chance to compare people from fish eating nation such as Japan with the Filipinos (south Asia rich in coconut) side by side: The Japanese look like zombies with very bad teeth while the Filipinos are shining health with perfect white teeth and lot of energy. Of course, this may be the effect of being raised in a big crowded stressy city versus pristine islands but makes me wonder anyway. |
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Here the experts are contradicting themselves by saying that DHA is proinflammatory while AA decreases TNFalpha production. They had better looking at the real things like LTB4 and PGE2 instead of hunting their cytokine markers and being caught in the causality puzzle ...
Neuro Endocrinol Lett. 2007 Dec;28(6):875-80.
Why fish oils may not always be adequate treatments for depression or other inflammatory illnesses: docosahexaenoic acid, an omega-3 polyunsaturated fatty acid, induces a Th-1-like immune response.
Maes M, Mihaylova I, Kubera M, Bosmans E.
Clinical Research Center for Mental Health, Antwerp, Belgium.
BACKGROUND: We have shown that a depletion of omega3 polysaturated fatty acids (PUFAs) plays a role in the pathophysiology of depression, in part because omega3 PUFAs have anti-inflammatory effects. omega3 PUFAs are frequently employed to treat depression. Most if not all antidepressants have negative immunoregulatory effects by decreasing the production of proinflammatory cytokines, such as interferon-gamma (IFNgamma) and/or increasing that of anti-inflammatory cytokines, such as interleukin10 (IL-10). AIM: The aim of the present study was to examine the immunoregulary effects of the omega3 PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the omega6 PUFA, arachidonic acid (AA), on the production of interferon-gamma (IFNgamma), interleukin-10 (IL-10) and tumor necrosis factor-alpha (TNFalpha). METHODS: This study examines the ex vivo effects of EPA (4.5 microM, 9 microM, 18 microM and 45 microM), DHA (1.3 microM, 3 microM, 6 microM and 13 microM) and AA (8 microM, 16 microM, 32 microM and 80 microM) on the LPS + PHA-stimulated production of IFNgamma, IL-10 and TNFalpha, and on the IFNgamma/IL-10 production ratio. Results: We found that EPA did not have any significant effects on the above cytokines. DHA significantly increased the IFNgamma/IL-10 production ratio, caused by a greater reduction in IL-10 than in IFNgamma. AA significantly decreased TNFalpha production. DISCUSSION: The results show that DHA induces a Th-1-like immune response and that AA has anti-inflammatory effects by decreasing the production of TNFalpha. Thus, the immune effects of omega3 PUFAs are not compatible with what is expected from antidepressive substances. The results of the present study show that treatment with fish oils, containing DHA, should be avoided in the treatment of depression. Toward this end, highly concentrated and pure EPA seems to be indicated.
PMID: 18063921
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Mutat Res. 2008 Feb 23. [Epub ahead of print]
4-Oxo-2-hexenal, a mutagen formed by omega-3 fat peroxidation:
Occurrence, detection and adduct formation.
Kasai H, Kawai K.
Department of Environmental Oncology, Institute of Industrial
Ecological Sciences, University of Occupational and Environmental
Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
The purpose of this review is to summarize our recent studies of a
novel mutagen, 4-oxo-2-hexenal. To identify the mutagens formed in a
model reaction of lipid peroxidation, linolenic acid methyl ester and
hemin were reacted with dG. A 4-oxo-2-hexenal-dG adduct (dG*) was
identified in the model reaction mixture. The 4-oxo-2-hexenal (4-OHE)
showed mutagenic activity in the Salmonella typhimurium strains TA100
and TA104. 4-OHE reacts with DNA to form dG, dC, and 5-methyl-dC(5-Me-
dC)-adducts (dG*, dC*, 5-Me-dC*) in vitro. After 4-OHE was orally
administered to mice, these adducts were detected in esophageal,
stomach and intestinal DNA by liquid chromatography coupled with
electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS). We
also confirmed the formation of 4-OHE during the heat processing of
edible vegetable oil, and during cooking. It was present at an
especially high concentration in broiled saury. 4-OHE is probably
generated by the oxidation of omega-3 fats. These results provide a
warning to humans, who may be exposed to this mutagen. Since 4-OHE
induces DNA adduct formation in experimental animal organs, further
studies on the carcinogenicity of 4-OHE and the detection of 4-OHE-DNA
adducts in human tissue will be required. |
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After reading the abstract in the post above, I did a search for a recipe for saury (apparently, a blue fish dish). I found a recipe that included the following dietary advice:
"The oil contained in blue fish cleanses our blood and helps prevent arteriosclerosis. Try to eat one serving every day."
Source: http://www.tec-tsuji.com/recipe2002/healthy/ht0136/index.html
I can't imagine advice that is much worse than that ! |
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| I used to be eating that broiled blue fish in the past and I always got terrible hiccough after eating more than 3 pieces ... |
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Saury is also used in pet food manufacture �?boiled for hours, extruded under high temperatures, coated in ex-restaurant grease and left exposed to the air and light for up to 2 years! Yum yum NOT. My kitteh will stick with his raw diet thanks. For any wondering if this diet could be good for a cat. He was 7 months when I got him on 21st April this year. He was sick and had terrible diarrhoea and weighed only 2.1 kg. Today he weighs 5kg, and doesn’t have an ounce of fat �?that’s what 10 weeks�?raw diet has done (and he is also disgustingly healthy and very active). |
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A new "finding" that is consistent with what I've been pointing out about fish oil for years now:
QUOTE: ...In the study, blister wounds on the arms of people taking fish oil supplements were compared to the wounds of people taking a placebo. The wounds healed in about the same amount of time �?but at the local cellular level, something unexpected happened. The levels of proteins associated with initiating and sustaining inflammation were higher in the blister fluid in people who had taken the active fish oil supplements. The researchers had expected those proteins to be lowered by the increased systemic presence of omega-3 fatty acids in the blood.
“That finding was hard to explain,�?said Jodi McDaniel, lead author of the study and an assistant professor of nursing at Ohio State University. “These proteins may have other functions that we don’t yet fully understand. And our results also suggested there could be a difference between men and women in the amount of inflammatory proteins that are produced, because on average, women had lower levels of one of the proteins.�?
If the polyunsaturated fatty acids in the fish oils do indeed delay acute wound healing, then they probably should be discontinued for awhile by patients scheduled for surgery, McDaniel said. They appear to have enough of an effect that patients should at least inform their doctors if they’re taking a fish oil supplement, she added... UNQUOTE.
Source: http://www.sciencedaily.com/releases/2008/07/080723162117.htm |
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| Probably, the inflammatory proteins induced by Omega-3 are due to the higher level of lipid peroxidation from these unsaturated fatty acids. |
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