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mbn_van-bc
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Date Joined Dec 2006
Total Posts : 950
| Posted 10/29/2010 10:03 AM (GMT -4) |   | I have a strong feeling the push to promote fish oils is linked to organic agriculture.
The fish are squished of their oil, then the bodies and bits sold as fertilizer, no??
More fish fertilizer, more fish oil.
More organic foods, more fish oil. | | Back to Top | | |
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Tom.
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Date Joined Jul 2006
Total Posts : 1245
| Posted 10/28/2010 10:18 AM (GMT -4) | | John2004 said...
Hi Tom, Regarding your question "at what price", I think right now, with regards to fish oil, we don't know what price, if any. If the pro-oxidant status of fish oil is up-regulating the bodies antioxidant defenses to the point where they contend with not only the pro-oxidant status of the fish oil, but also provide more benefit than ingesting anti-oxidants, or provide a good compliment go ingesting anti-oxidants, then there is no price to pay. There are trade-offs with everything in life but the bottom line question is whether or not eating fish and/or taking fish oil supplements is in general, good for you, and the data to date seems to indicate that it is.
Based on the information to date, we do know that there is a price to pay both positive and negative. The "mass media" has focused their attention on the wonderful, miraculous, almost god-like quality of fish and fish lipids. There is another side to the story that doesn't get published in places like, Prevention magazine, all the "Doctor" T.V. shows, and (excuse me I don't mean to be rude here) but, supplement companies as well. Often, the positive aspects are hyped up leaving no room in the mind of the consumer to accept anything other than good. It's almost a "How dare you!" lashing, even when somehow the conscience mind knows there is another side to the story. So, folks go about their day popping this and that, not aware of the scattered, pieces of the puzzle that lay dormant and unrecognized by the masses. Research by brilliant minds who spend countless hours doing human and animal studies that will probably never reach "mass market" appeal, but never the less, deserve it just the same. Unless someone puts those puzzle pieces together and provides this information there is none, for the majority. Since the majority doesn't have the time to ferret it out, send their brain back to biology, chemistry and anatomy 101, and complete the road map and then translate it into easy to understand information for the non-scientific mind. The information is out there as you've seen from my writings but it's not a hot, popular topic as the curative, therapeutic qualities, of which is only one side of the complete, overall story.
John2004 said...
If most diseases that omega-3 fatty acids show health-improving effects on are characterized by elevated oxidative stress, then it seems omega-3 is not causing a harmful pro-oxidant status in the body but the opposite is happening, the fish oil is somehow reducing oxidative stress in the body. Fish oil might not produce such anti-oxidant effects in a test tube or a mouse, but perhaps it does produce anti-oxidant effects in the human body. The fish oil does not appear to be producing harmful pro-oxidant effects in humans since fish oil / omega-3 has shown health improving effects on diseases characterized by elevated oxidative stress.
But it does show this and we know it does.
John2004 said...
We don't really know what is going on at the moment so more conclusive long term in-vivo studies need to be made. Like all supplements, when you take fish oil you are taking a leap of faith to a certain extent.
Yes, long term studies are always needed to really see the true effect in humans, but most of us don't have several lifetimes to wait and change course so animal models become the next closest thing to give us some type of prudent course of action now.
John2004 said...
Regarding the pro-oxidant status of fish oil, it could turn out that this is the very thing that allows fish oil to provide it's benefits, we just don't know at the moment. Even if a little pro-oxidant activity induced by fish oil turns out to be a good thing, it seems there will be an optimal range and it seems likely to me that when the fish oil gets close to the point of becoming rancid, it will be too far in that direction and likely cause problems at that point.
Keep in mind, things happen before it can be detected rancid.
John2004 said...
Unless it is shown that eating fish and/or taking fish oil is producing harmful effects in the human body (pro-oxidant or otherwise), I will probably continue to take my fish oil (as fresh as I can get it) since the data to date seems to predominantly show benefit.
It has been shown. I've tried to put some of the information here. There is more and it takes so much time. It's like following a never ending treasure map. It's fun but you know there is more out there to be uncovered. It can be quite addictive if you're interested in such topics. What you said illustrates my point exactly -- "The data seems to predominantly show" The reason why it is predominant, is that is what is hot and popular.
John2004 said...
I think you are an excellent researcher Tom, and I like reading your posts. I am going to keep following your research in this area but I'm hoping you will also research both sides of the coin with the same diligence and look into the possible benefits as well as the possible harms of these types of dietary fats.
I agree that to be a non-biased, health-science journalist, one must present both sides. The reason why I haven't written loads of information on the positive aspects is because that is not what is needed. We already know many of the benefits. I'm writing about the other side which folks would probably never know about unless someone took the time to research the data and write about it. I would never know this other side if I hadn't looked into it.
Keep a close eye on this thread because there is more to learn, coming soon.. | | Back to Top | | |
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John2004
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Date Joined Sep 2004
Total Posts : 141
| Posted 10/27/2010 5:11 PM (GMT -4) | | Hi Tom,
Regarding your question "at what price", I think right now, with regards to fish oil, we don't know what price, if any. If the pro-oxidant status of fish oil is up-regulating the bodies antioxidant defenses to the point where they contend with not only the pro-oxidant status of the fish oil, but also provide more benefit than ingesting anti-oxidants, or provide a good compliment go ingesting anti-oxidants, then there is no price to pay. There are trade-offs with everything in life but the bottom line question is whether or not eating fish and/or taking fish oil supplements is in general, good for you, and the data to date seems to indicate that it is.
If most diseases that omega-3 fatty acids show health-improving effects on are characterized by elevated oxidative stress, then it seems omega-3 is not causing a harmful pro-oxidant status in the body but the opposite is happening, the fish oil is somehow reducing oxidative stress in the body. Fish oil might not produce such anti-oxidant effects in a test tube or a mouse, but perhaps it does produce anti-oxidant effects in the human body. The fish oil does not appear to be producing harmful pro-oxidant effects in humans since fish oil / omega-3 has shown health improving effects on diseases characterized by elevated oxidative stress.
We don't really know what is going on at the moment so more conclusive long term in-vivo studies need to be made. Like all supplements, when you take fish oil you are taking a leap of faith to a certain extent.
Regarding the pro-oxidant status of fish oil, it could turn out that this is the very thing that allows fish oil to provide it's benefits, we just don't know at the moment. Even if a little pro-oxidant activity induced by fish oil turns out to be a good thing, it seems there will be an optimal range and it seems likely to me that when the fish oil gets close to the point of becoming rancid, it will be too far in that direction and likely cause problems at that point.
Unless it is shown that eating fish and/or taking fish oil is producing harmful effects in the human body (pro-oxidant or otherwise), I will probably continue to take my fish oil (as fresh as I can get it) since the data to date seems to predominantly show benefit.
I think you are an excellent researcher Tom, and I like reading your posts. I am going to keep following your research in this area but I'm hoping you will also research both sides of the coin with the same diligence and look into the possible benefits as well as the possible harms of these types of dietary fats. | | Back to Top | | |
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Tom.
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Date Joined Jul 2006
Total Posts : 1245
| Posted 10/27/2010 11:57 AM (GMT -4) | | | To your point, there is a some evidence indicating a pro-oxidant can trigger the natural defense mechanism to combat free radicals generated by the pro-oxidant. Some theory suggests that even this up-regulation of antioxidant defenses caused by the pro-oxidant can cause more of an overall antioxidant protection throughout the body. But at what price? Protection In some cases, like cancer for example, a pro-oxidant might be beneficial against the cancerous cell, although potential consequences to healthy cells would still exist. | | Back to Top | | |
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John2004
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Date Joined Sep 2004
Total Posts : 141
| Posted 10/25/2010 10:32 AM (GMT -4) | | I found a couple of studies that suggest the pro-oxidant status of fish oil may actually be a benefit by causing the body to modulate it's natural defense mechanisms against free radicals. I had always thought the endogenous antioxidants made by our own bodies were more powerful than the one's we ingest from food or supplements. It would be interesting if it turned out that ingesting a pro-oxidant of the right type and strength is actually better than ingesting anti-oxidants, or at least a good compliment to antioxidants. It sort of reminds me of immunization where injecting a weakened form of a virus into your bloodstream can immunize you against the virus. Perhaps this is one reason why exercise is beneficial even though it generates free radicals. Here is a site which references a study done by researchers from the Paris-based Laboratory of Micro-nutrients and Cardiovascular Disease http://english.upmc.fr/UK/info/00 (Omega-3 Fatty Acids: Modulators of Antioxidant Defense). Reference to and overview of, the study: http://www.straightfromthedoc.com/50226711/omega3_fatty_acids_modulators_of_antioxidant_defense.php Does anyone have a link to the full study referenced in the link above ? I went to the "science direct" link and the French university link but did not see the study. If most diseases that omega-3 fatty acids show health-improving effects on are characterized by elevated oxidative stress, it seems the fish oil must be causing a reduction of oxidation in the body even though it can have a pro-oxidant status in and of itself. Perhaps something like what is proposed at the link above may be going on in the body so that ingestion of fish oil turns out to be more of an advantage than a disadvantage, even in light of the fish oil's pro oxidant status. With all the evidence on the beneficial effects of fish oil it seems something is going on to counter the possible negative side effects of the pro-oxidant status of the fish oil. Here is another study along the same lines... "Fish oil feeding alters liver gene expressions to defend against PPAR activation and ROS production" http://ajpgi.physiology.org/cgi/content/short/282/2/G338 It seems we still need to learn much more, but for now I'm going to take my fish oil as fresh as I can get it, but I'm still going to take it. | | Back to Top | | |
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Tom.
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Total Posts : 1245
| Posted 10/19/2010 10:11 AM (GMT -4) | | An interesting article about how dietary fats react when processed and/or altered ...
Fate in digestion in vitro of several food components, including some toxic compounds coming from omega-3 and omega-6 lipids
Encarnación Goicoecheaa, Esther F.A. Brandonb, Marco H. Bloklandb and María D. Guilléna
Food Technology Department, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain
National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
Received 11 May 2010; Accepted 2 October 2010. Available online 10 October 2010.
Abstract
In this study it was proved the formation of oxygenated alpha,beta-unsaturated aldehydes (OαβUAs) of 6, 7, 9 and 10 carbon atoms during the thermal treatment (190 °C with aeration) of a commercial vegetable oil rich in omega-3 and omega-6 acyl groups, which also contained small amounts of added proteins and carbohydrates to produce barbecue aroma when heated.
The OαβUAs detected by Solid Phase Microextraction (SPME) followed by Gas Chromatography/Mass Spectrometry (GC/MS) were: 4-hydroxy-2-hexenal, 4-oxo-2-hexenal and 4,5-epoxy-2-heptenals, coming from omega-3 acyl groups; and 4-hydroxy-2-nonenal, 4-oxo-2-nonenal and 4,5-epoxy-2-decenals, coming from omega-6 acyl groups.
Mixtures of this oil, either thermodegraded or not, with standard food were submitted to an in vitro digestion model.
The study of the digestion products obtained revealed that OαβUAs remained unaltered, being bioaccessible in the gastrointestinal tract and so able to reach the systemic circulation. Besides, it was evidenced that during digestion Maillard, esterification and oxidation reactions take place.
LINKPost Edited (Tom.) : 10/22/2010 3:58:45 AM (GMT-4) | | Back to Top | | |
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Tom.
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Date Joined Jul 2006
Total Posts : 1245
| Posted 10/19/2010 10:11 AM (GMT -4) | | Albedo,
Hey you're welcome. It's not easy or quick to do this research. I post it here for my benefit as well as for all my faithful followers and those who just lurk and absorb the important information but never come out of the shadows to say anything! Here's to your health! Enjoy! | | Back to Top | | |
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Tom.
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Date Joined Jul 2006
Total Posts : 1245
| Posted 10/11/2010 10:15 AM (GMT -4) | | As far as "-prostanes" are concerned, it isn't a simple subject to discuss. Since around the early 1990's several metabolites have been discovered such as isoprostanes, neuroprostanes, phytoprostanes and probably more such metabolites that PUFA's generate via peroxidation that can participate in a wide variety of altered, abnormal functions in an individual or an organ. T Durand et al; Isoprostanes and phytoprostanes: Bioactive lipids; Biochemie (2010) / Ullrich Jahn et al; Beyond prostaglandins--chemistry and biology of cyclic oxygenated metabolites formed by free-radical pathways from polyunsaturated fatty acids; Angew Chem Int Ed 47(32):5894-955 (2008)
For example, F2-isoprostanes are from the peroxidation of arachidonic acid, Milne GL et al; Biomarkers. 2005 Nov;10 Suppl 1:S10-23.
F3-isoprostanes are produced from the peroxidation of EPA in vivo. Gao L et al; J Biol Chem. 2006 May 19;281(20):14092-9. Epub 2006 Mar 28.
DHA may be oxidized into non-enzymatically into F4-, D4-, E4-, A4- and J4-neuroprostanes and are an indicators of oxidative stress in the retina and brain. Omega-3 fatty acids, the brain and retina. By Artemis P. Simopoulos, Nicolás G. Bazán
It can not be concluded that just because F2 levels decrease that fish oil EPA and DHA are not oxidized and not contributing to oxidative damage. For example, this study, from Emilie Mas et al, entitled: The omega-3 fatty acids EPA and DHA decrease plasma F2-isoprostanes: Results from two placebo-controlled interventions, one would assume that there would be no lipid peroxidation in fish oil. But that not the whole picture.
There has been allot of attention lately surrounding the shift toward omega-3 fatty acids but proof and evidence is mounting indicating a increased exposure to lipid peroxidation. Song WL et al; J Biol Chem. 2009 Aug 28;284(35):23636-43.
In this study entitled Novel Eicosapentaenoic Acid-derived F3-isoprostanes as Biomarkers of Lipid Peroxidation; Wen-Liang Song et al noted when the mice were fed a diet without fish oil there was no significant change in urine in two major F3-isoprostane that measure EPA oxidation. When the mice were fed 1% fish oil, urinary F3-isoprostane levels (remember these are the ones that measure oxidation of EPA), increased.
What is interesting to note is that urinary F2 levels (the ones that measure arachidonic acid peroxidation) decreased with the lower levels of fish oil. When the mice were fed 5% fish oil, F3's significantly increased in a short time span and increased significantly higher the longer the duration of consumption. With the higher fish oil consumption, even the F2's significantly increased.
Also noted from, Wen-Liang Song et al:
"Some of the studies that reported benefits of fish consumption were conducted on populations where the fish were lean and relatively deficient in ω-3 PUFA.
Because EPA and DHA possess more double bonds than AA, (arachidonic acid) they may be more susceptible to oxidation by free radicals than is AA. This might adversely influence cell membrane function or constrain beneficial effects of fish oils via autacoidal effects of F3- and F4-iPs.
Moreover, multiple iPs (isoprostanes) are likely to be formed together under conditions of oxidative stress, rendering assumptions based on concentrations or comparative bioactivities of single species difficult to relate to conditions in vivo." | | Back to Top | | |
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Tom.
Registered Member
Date Joined Jul 2006
Total Posts : 1245
| Posted 10/11/2010 10:07 AM (GMT -4) | | Albedo,
I'm glad you find my researched posts informative. I already answered the question about Ross's shotgun approach to posting all those headlines.. HEREAbedo, Let me answer you with this ... "The polyunsaturated fatty acids in biological membranes serve as both the target and source of oxidative damage and can be regarded as the most unstable class of biomolecules in the body. Lipid peroxides arising from both spontaneous and enzymatic oxidation of polyunsaturated fatty acids are the major source of endogenous DNA damage linked to various age-related pathologies and initiating carcinogenesis" Rejuvenation Res. 2010 Apr-Jun;13(2-3):285-7."In humans, fish consumption or administration of DHA has been associated with cognitive improvement in many, but not all, studies" J Alzheimers Dis. 2010;20(3):737-47. Therefore it is not conclusive that fish oil absolutely improves cognitive function. Also, what about long-term consumption of highly unstable, ω-3 polyunsaturated fish oil. How does this affect life span? "Progressive neurological dysfunction is a key aspect of human aging. Because of underlying differences in the aging of mice and humans, useful mouse models have been difficult to obtain and study. . . The senescence-accelerated mice are a collection of inbred mouse strains developed as models of accelerated aging, and include nine short-lived, senescence-accelerated mouse prone strains (SAMP) . . . The SAMP strains exhibit several features that make them interesting models of human aging, including age-associated early onset of senile amyloidosis, degenerative arthropathy, cataracts, osteoporosis and osteoarthritis, reduced fecundity and early loss of fertility." Carter, et al"The effects of fish oil including ω-3 polyunsaturated fatty acids on aging and lifespan are not well understood. In this (recent) study, the influence of long-term ingestion of fish oil on lifespan was examined in senescence-accelerated (SAMP8) mice. Researchers investigated the effects of dietary fish oil on lifespan and on lipid composition and oxidative stress in plasma and liver in SAMP8 mice. Male mice were fed a fish oil diet (5% fish oil and 5% safflower oil) or a safflower oil diet (10% safflower oil) from 12 wk of age. The SAMP8 mice fed fish oil did not have a longer maximum lifespan and had a shorter average lifespan than mice fed safflower oil. To examine the mechanism underlying these results, the effects on oxidative stress of long-term ingestion of fish oil were also examined. SAMP8 mice fed fish oil for 28 wk showed strong oxidative stress that caused hyperoxidation of membrane phospholipids and a diminished antioxidant defense system due to a decrease in tocopherol compared with mice fed safflower oil. These findings suggest that intake of fish oil increases oxidative stress, decreases cellular function, and causes organ dysfunction in SAMP8 mice, thereby promoting aging and shortening the lifespan of the mice." Tsuyoshi Tsuduki Ph.D., et alIt is well known that oxidized lipids causes oxidative damage. Oxidative damage shortens telomeres ". . .Oxidative damage to both nuclear and mitochondrial DNA has detrimental effects, leading to uncontrolled cell proliferation or accelerated cell death". Kevin C. Kregel, et al"Recent results from international cellular, animal and human trials indicate that the oxidised products in fish oils may have potential carcinogenic and pro-inflammatory actions. These products have the potential to increase the risk of atherosclerosis and thrombosis and reduce the potential benefits of omega-3 fatty acids. Dr Turner, a lipids scientist with Crop & Food Research, says that unfortunately, fish oils containing omega-3 fatty acids are unstable and more vulnerable to oxidation than vegetable oils or other animal fats. When fish oils come into contact with oxygen and are exposed to metals, light and heat they degrade. Oxidation of the oil accelerates after extraction from the fish and during subsequent storage." Dr Rufus Turner, et al; Food & Crop Research | | Back to Top | | |
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albedo
Registered Member
Date Joined Jan 2008
Total Posts : 1049
| Posted 10/8/2010 7:24 PM (GMT -4) | |
Tom, I love reading your posts and find always a balanced and researched point of view. I hope you do not mind if I report here, without having read them though, the studies which Ross7755 reports HERE as contradicting your thesis. I do this mostly to keep a track for my research in one of the most interesting treads in the Forum. Btw many studies mention the F(2) isoprostanes test which you let me discover; would like to pass this test. I am visiting LEF in November and would love if this was possible. Any progress?
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Erdogan H, Fadillioglu E, Ozgocmen S, Sogut S, Ozyurt B, Akyol O, Ardicoglu O. Effect of fish oil supplementation on plasma oxidant/antioxidant status in rats. Prostaglandins Leukot Essent Fatty Acids. 2004 Sep;71(3):149-52.
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Higdon JV, Liu J, Du SH, Morrow JD, Ames BN, Wander RC. Supplementation of postmenopausal women with fish oil rich in eicosapentaenoic acid and docosahexaenoic acid is not associated with greater in vivo lipid peroxidation compared with oils rich in oleate and linoleate as assessed by plasma malondialdehyde and F(2)-isoprostanes. Am J Clin Nutr. 2000 Sep;72(3):714-22.
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Iraz M, Erdogan H, Ozyurt B, Ozugurlu F, Ozgocmen S, Fadillioglu E. Brief communication: omega-3 essential fatty acid supplementation and erythrocyte oxidant/antioxidant status in rats. Ann Clin Lab Sci. 2005 Spring;35(2):169-73.
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Mas E, Woodman RJ, Burke V, Puddey IB, Beilin LJ, Durand T, Mori TA. The omega-3 fatty acids EPA and DHA decrease plasma F(2)-isoprostanes: Results from two placebo-controlled interventions. Free Radic Res. 2010 Jun 14.
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Mori TA, Woodman RJ, Burke V, Puddey IB, Croft KD, Beilin LJ. Effect of eicosapentaenoic acid and docosahexaenoic acid on oxidative stress and inflammatory markers in treated-hypertensive type 2 diabetic subjects. Free Radic Biol Med. 2003 Oct 1;35(7):772-81.
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Nalsen C, Vessby B, Berglund L, Uusitupa M, Hermansen K, Riccardi G, Rivellese A, Storlien L, Erkkila A, Yla-Herttuala S, Tapsell L, Basu S. Dietary (n-3) fatty acids reduce plasma F2-isoprostanes but not prostaglandin F2alpha in healthy humans. J Nutr 2006;136:1222 – 1228.
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Palozza P, Sgarlata E, Luberto C, Piccioni E, Anti M, Marra G, Armelao F, Franceschelli P, Bartoli GM. n-3 fatty acids induce oxidative modifications in human erythrocytes depending on dose and duration of dietary supplementation. Am J Clin Nutr. 1996 Sep;64(3):297-304. Accessed at http://www.ajcn.org/cgi/reprint/64/3/297
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Quaggiotto P, Leitch JW, Falconer J, Murdoch RN, Garg ML. Plasma F2[alpha]-isoprostane levels are lowered in pigs fed an (n-3) polyunsaturated fatty acid supplemented diet following occlusion of the left anterior descending coronary artery. Nutr Res 2000;20:675 – 684.
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Richard D, Kefi K, Barbe U, Bausero P, Visioli F. Polyunsaturated fatty acids as antioxidants. Pharmacol Res. 2008 May 18. [Epub ahead of print]
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Thies F, Garry JM, Yaqoob P, Rerkasem K, Williams J, Shearman CP, Gallagher PJ, Calder PC, Grimble RF. Association of n-3 polyunsaturated fatty acids with stability of atherosclerotic plaques: a randomised controlled trial. Lancet. 2003 Feb 8;361(9356):477-85.
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Wander RC, Du SH. Oxidation of plasma proteins is not increased after supplementation with eicosapentaenoic and docosahexaenoic acids. Am J Clin Nutr. 2000 Sep;72(3):731-7.>>
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Andrew Xnn
Registered Member
Date Joined Oct 2010
Total Posts : 14
| Posted 10/7/2010 10:05 AM (GMT -4) | | | Are sardines and extra virgin olive oil good for ones health if they are not cooked? | | Back to Top | | |
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Tom.
Registered Member
Date Joined Jul 2006
Total Posts : 1245
| Posted 10/6/2010 10:48 AM (GMT -4) | | Lipid Peroxidation Products Are Elevated in Fish Oil Diets Even in the Presence of Added Antioxidants
Michael J. Gonzalez, J. Ian Gray, Rachel A. Schemmel, Leroy Dugan, Jr. and Clifford W. Welsch1,2,
Departments of Food Science and Human Nutrition; * Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824
Purified corn and fish oil diets with different types and concentrations of antioxidants were evaluated for oxidation products. In addition, a determination of different organ and carcass oxidation product levels was performed.
Peroxide value and thiobarbituric acid assays were performed on the diets immediately after mixing (0 h) and 24, 48 and 72 h after being fed to mice. The AIN-recommended level of antioxidant addition (butylated hydroxytoluene, 0.02 g/100 g oil) and even the addition of 100 times this level (2 g/100 g oil), although decreasing the level of oxidation products, failed to totally prevent oxidative deterioration in diets high in fish oil.
Furthermore, other antioxidants added in excess to the fish oil diets also failed to completely suppress oxidative deterioration of the diets and, in addition, when fed daily to mice for a period of 4 wk, caused an accumulation of lipid peroxidation products in certain organs (e.g., heart, skeletal muscle, mammary glands) and in the carcass.
These results provide evidence that in the preparation of fish oil diets, the addition of antioxidants at the AIN-recommended level, or even levels substantially higher, does not completely suppress oxidative deterioration of experimental diets.
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Tom.
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Date Joined Jul 2006
Total Posts : 1245
| Posted 10/6/2010 10:48 AM (GMT -4) | | Omega-3 LC PUFA Contents and Oxidative Stability of Encapsulated Fish Oil Dietary Supplements
Author: Wojciech Kolanowskia
Abstract
The aim of this study was to examine omega-3 LC PUFA content and oxidative stability of fish oil dietary supplements available in Poland. Nineteen brands of fish body oil and fish liver oil capsules were purchased over the counter and analyzed. Oil content, fatty acid composition and peroxide value were determined. The label claims for EPA and DHA for the majority of the products were presented with reasonable accuracy. However, it can be supposed that the oxidative stability of some fish oil products available on the market might not be sufficient to ensure health quality and safety during longer storage.
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Tom.
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Total Posts : 1245
| Posted 9/20/2010 12:53 PM (GMT -4) | | Isoprostanes are prostaglandin-like compounds formed in vivo from the free radical-catalyzed peroxidation of essential fatty acids. These compounds are accurate markers of lipid peroxidation in both animal and human models of oxidative stress.
It is interesting to note that in this study, low dose DHA supplementation (200 mg day) appears to have an antioxidant effect whereas a high dose (1600 mg day) appears to be a pro-oxidant as measured by an increase of urinary isoprostane. | | Back to Top | | |
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Tom.
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Date Joined Jul 2006
Total Posts : 1245
| Posted 9/9/2010 10:19 AM (GMT -4) | | Spain,
Although some studies have shown that some people have experienced immunosuppressive effects at doses as low as 0.9 g/day for EPA and 0.6 g/day for DHA (see the Linus Pauling Institute website for more details). However, that is not the norm. It is larger doses which suppress immune function.
You misread the previous study. It didn't say small dose, so I don't understand what prompted you to make that statement.
Also, never once has this thread mentioned or endorsed a low fat diet, or high carb diet or eliminating coconut (saturated fat). So again, I don't understand why you needed to claim that statement on this thread either.
This thread is about dangerous effects of lipid peroxidation, understanding it, knowing how to spot sources that are high in it and making better dietary fat choices.
This thread is not about avoiding proper, good fats. Nope far from it. Fats are essential. | | Back to Top | | |
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SpainEurope
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Date Joined Dec 2008
Total Posts : 709
| Posted 9/8/2010 5:29 PM (GMT -4) | | A small dose of fish oil -1 or 2 grams- does not suppress immune function, it's ridiculous.
A low fat diet is a high carb diet. Problem is carbs, no fats. Every body needs omega 3 and saturated and monounsaturated fats. Read Weston Price Foundation.
Low fat = wrong | | Back to Top | | |
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Tom.
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Date Joined Jul 2006
Total Posts : 1245
| Posted 9/8/2010 10:16 AM (GMT -4) | | Dietary fatty acids and oxidative stress in the heart mitochondria
Study compared the effects of different oils on oxidative stress in rat heart mitochondria, as well as on plasma parameters used as risk factors for cardiovascular disease.
The rats were fed for 16 weeks with:
coconut (saturated)
olive oil (monounsaturated)
fish oil (polyunsaturated)
The cardiac mitochondria from rats fed with coconut oil showed the lowest concentration of oxidized proteins and peroxidized lipids.
The fish oil diet leads to the highest oxidative stress in cardiac mitochondria, an effect that could be partly prevented by the antioxidant probucol. Total and LDL cholesterols decreased in plasma of rats fed fish oil, compared to olive and coconut oils fed rats.
A diet enriched in (coconut) saturated fatty acids offers strong advantages for the protection against oxidative stress in heart mitochondria.
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Tom.
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Total Posts : 1245
| Posted 9/8/2010 10:15 AM (GMT -4) | | | Pollyunsaturated fatty acids (PUFAs) suppress the immune system and the reason for their anti-inflammatory properties. If you're trying to seasonally boost the immune system or have a compromised immune system, you would want to avoid PUFAs. LINK | | Back to Top | | |
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Tom.
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Total Posts : 1245
| Posted 9/8/2010 10:15 AM (GMT -4) | | For the parents out there
"Infant formulas are highly sensitive to the Maillard reaction during manufacturing, while this reaction induces significant loss in protein nutritional value and safety." LINK | | Back to Top | | |
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Tom.
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Date Joined Jul 2006
Total Posts : 1245
| Posted 8/9/2010 2:25 PM (GMT -4) | | I found this information interesting and thought it should go here. Keep in mind this previous topic I wrote when considering supplementing with melatonin:
http://forum.lef.org/default.aspx?f=35&m=26483
Melatonin may counteract lipid peroxidation
www.ncbi.nlm.nih.gov/pubmed/20674543
"Eighty years ago, Burr and Burr, introduced for the first time the concept of essential fatty acids. Now is very well known that requirements for polyunsaturated fatty acids PUFAs can not be met by de novo metabolic processes within mammalian tissues.
Animals are absolutely dependent on plants for providing the two major precursors of the n-6 and n-3 fatty acids, C18:2n-6; linoleic and C18:3n-3; alpha-linolenic acids. In animal tissues these precursors are transformed to fatty acids containing three to six double bonds.
During the last four decades the interest in polyunsaturated fatty acids has augmented manifolds, and the number of published studies is rising each year. The current impetus for this interest has been mainly the observation that PUFAs and their metabolites have several physiological roles including: energy provision, membrane structure, cell signaling and regulation of gene expression.
In addition the observation that PUFAs are targets of lipid peroxidation opens a new important area of investigation.
Melatonin, the main secretory product of the pineal gland, efficiently scavenges both the hydroxyl and peroxyl radicals counteracting lipid peroxidation in biological membranes.
In addition the two key pineal biochemical functions, lipoxygenation and melatonin synthesis may be synergistically regulated by the status of n-3 essential fatty acids. ..."
(This next paragraph concurs with my research above regarding lipid peroxidation and eyesight)
"... At the retina level, free radicals may preferentially react with the membrane polyunsaturated fatty acids leading to the release of lipoperoxide radicals. These lipoperoxides can induce oxidative stress linked to membrane lysis, damage to neuronal membranes may be related to alteration of visual function."
Antioxidant advantages
www.ncbi.nlm.nih.gov/pmc/articles/PMC2582546/
"Another advantage of melatonin over classical antioxidants is its lack of prooxidative actions.
All classical antioxidants are potential electron donors and they exhibit both reduced and oxidized forms. Once they donate an electron to neutralize a free radical, they are transformed from a reduced to an oxidized state. Usually, the oxidized form will be regenerated to the reduced state through the mechanism known as redox reaction or recycling.
In this pathway, the recycling of vitamin C or vitamin E occurs at the expense of GSH. In many cases, however, GSH is a better antioxidant than either vitamin C or vitamin E.
Because these antioxidants are electron donors and exhibit redox reactions, their oxidized forms also can oxidize other molecules. Therefore, classical antioxidants are prooxidants.
Melatonin sacrifices itself and does not participate in redox cycling after scavenging free radicals. As previously mentioned, melatonin not only does not consume cellular GSH, it also preserves or even increases the content of GSH in tissues. Thus, melatonin is classified as a suicidal or terminal antioxidant."
Melatonin sources
www.ncbi.nlm.nih.gov/pubmed/10899700
"Melatonin has been detected in vegetables, fruits and a variety of herbs. In some plants, especially in flowers and seeds (the reproductive organs which are most vulnerable to oxidative insults), melatonin concentrations are several orders of magnitude higher than measured in the blood of vertebrates.
Melatonin in plants not only provides an alternative exogenous source of melatonin for herbivores but also suggests that melatonin may be an important antioxidant in plants which protects them from a hostile environment that includes extreme heat, cold and pollution, all of which generate free radicals.Post Edited (Tom) : 8/9/2010 1:41:13 PM (GMT-4) | | Back to Top | | |
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Tom.
Registered Member
Date Joined Jul 2006
Total Posts : 1245
| Posted 8/9/2010 1:19 PM (GMT -4) | | | | |
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Tom.
Registered Member
Date Joined Jul 2006
Total Posts : 1245
| Posted 7/6/2010 10:51 AM (GMT -4) | | This link to the study below is an very interesting hypothesis of an oxidative stress-induced cancer apoptosis mechanism. In this hypothesis they referring to breast cancer. What I was able to glean from this article can be basically summed up from this statement:
"We found that women with genetic polymorphisms causing lower or no activity in detoxifying genes (GSTM1, GSTT1, GSTP1) had more protection from marine n-3 fatty acids than those with common alleles, putatively because more cytotoxic peroxidation agents could reach the cancerous and pre-cancerous cells and cause damage."
Remember it is only a theory/hypothisis at this point. Never the less, it is important to include here for discussion. In case anyone is interested, here is the link:
http://breast-cancer-research.com/content/9/1/201 | | Back to Top | | |
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Tom.
Registered Member
Date Joined Jul 2006
Total Posts : 1245
| Posted 7/5/2010 1:28 PM (GMT -4) | | Study Abstract
Polyunsaturated fatty acids (PUFAs) have anti-inflammatory effects at low concentrations; however increased dietary consumption may conversely increase susceptibility to oxidation by free radicals.
The objective of this study was to determine the effects of PUFAs on selective oxidative injury and inflammatory biomarkers in canine urine and serum.
Dogs (n=54) consumed a diet supplemented with 0.5% conjugated linoleic acid/dry matter, 1.0% conjugated linoleic acid/dry matter, or 200 mg/kg docosahexaenoic acid/eicosapentaenoic acid for 21 days. All dogs exhibited significantly increased plasma PUFA concentrations. All dogs had significant elevations in urinary F2a isoprostane concentration, though dogs consuming a diet containing 1.0% conjugated linoleic acid/dry matter had the highest increase (P=.0052). Reduced glutathione concentrations within erythrocytes decreased significantly in all three dietary treatment groups (P=.0108). Treatment with diets containing 1.0% conjugated linoleic acid/dry matter resulted in the greatest increase in oxidant injury.
Caution should be exercised when supplementing PUFAs as some types may increase oxidation.
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