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| | From:  taka00381 (Original Message) | Sent: 1/2/2008 2:46 PM |
Hans, you have been talking about your parents and the pre-vegetable oil era people having Mead acid in their cells. Novadays people and farmed animals are fed vegetable oils so they are loaded with AA instead. But how about the wild animals, they are still eating like they were thousands of years ago so there should be some Mead acid in them. Here is one example study looking at lipids in 42 mammalian species and all they are finding are n-3 to n-6 PUFAs. I don't have access to the full text but it's unlikely they used only animals kept in ZOO and fed vegetable oils. I have yet to find some report of Mead acid in game meat or wild species (except the elongated Mead acid derivative in Turkeys I posted on the other thread). Does it mean that the wild animals are getting enough Omega-3 and Omega-6 PUFAs in their natural diet to prevent the synthesis of Mead acid?
Aging Cell. 2007 Feb;6(1):15-25. Epub 2006 Dec 5.
N-3 polyunsaturated fatty acids impair lifespan but have no role for metabolism.
Valencak TG, Ruf T.
Research Institute of Wildlife Ecology, University of Veterinary Medicine, Savoyenstrasse 1, A-1160 Vienna, Austria. teresa.valencak[at]vu-wien.ac.at
Although generally considered as beneficial components of dietary fats, polyunsaturated fatty acids (PUFA) have been suspected to compromise maximum lifespan (MLSP) in mammals. Specifically, high amounts of phospholipid PUFAs are thought to impair lifespan due to an increase in the susceptibility of membranes to lipid peroxidation and its damaging effect on cellular molecules. Also, there is evidence from in vitro studies suggesting that highly unsaturated PUFAs elevate basal metabolic rate (BMR). Previous comparative studies in this context were based on small sample sizes, however, and, except for one study, failed to address possible confounding influences of body weight and taxonomic relations between species. Therefore, we determined phospholipid membrane composition in skeletal muscle from 42 mammalian species to test for a relation with published data on MLSP, and with literature data on BMR (30 species). Using statistical models that adjust for the effects of body weight and phylogeny, we found that among mammals, MLSP indeed decreases as the ratio of n-3 to n-6 PUFAs increases. In contrast to previous studies, we found, however, no relation between MLSP and either membrane unsaturation (i.e. PUFA content or number of double bonds) or to the very long-chain, highly unsaturated docosahexaenoic acid (DHA). Similarly, our data set gave no evidence for any notable relation between muscle phospholipid fatty acid composition and BMR, or MLSP and BMR in mammals. These results contradict the 'membrane pacemaker theory of aging', that is, the concept of a direct link between high amounts of membrane PUFAs, elevated BMR, and thus, impaired longevity.
PMID: 17156083 |
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There's a lot that needs to be clarified. For example, did they study only animals that live much shorter lives than humans? Also, they are talking about PUFAs in cells, and I am not arguing against this, but rather to replace the AA or an omega 3 with Mead acid, then see what happens. Now let's consider humans. We can see from statistics when people often die of "heart disease" and certain cancers, for instance. Both of these seem to be directly related to PUFAs in the typical diet (in the majority of cases), and so if a large number of people die of these "diseases" well before the age of let's say 90, it's clear that this is significant for human life expectancy, and this particular study is not especially useful, though it would be nice to see a study that is "on point," that is, it compares animals with Mead acid in their cells to those with AA and/or omega 3 PUFAs.
In fact, I remember writing a post for another newsgroup about an animal that was injured, taken into captivity, then died for reasons the "experts" could not explain. I suggested that these "experts" may have thought the animal required "essential fatty acids," and killed it by giving it too much dietary omega 6 and/or 3 PUFAs. |
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It seems to me that the most likely explanation is that the Mead acid (n-9 PUFA) can co-exist with the n-3 and n-6 PUFAs which seem to be present even in the animals at wild. The experts probably screwed it up by claiming that Mead acid appears only in the absence of the n-3/n-6 "EFAs". There is probably some threshold for the "EFAs" beyond which the synthesis of Mead acid is greatly suppressed. But this is all just speculation because no one has apparently looked for the presence of Mead acid in the wild animals.
It may be even possible, that humans can do well with "EFAs" within their natural life span which is ~40 years. The "chronic" diseases usually develop after this age. But if they want to live past what the evolution set as their reproductive age it may be advantageous to remove the EFAs from their bodies. EFAs may be indeed "essential" for the reproduction and growth but can backfire later like the TOR/insulin signaling is said to do. Some scientists say that the aging is just uncontrolled run out of the developmental program past the reproductive age - perhaps we can suppress its deleterious effects by reducing the "EFAs" ... |
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| Look at all the "childhood diseases" that we are told are "epidemic" or becoming so - probably all are due to AA to one degree or another. I had several conditions as a child that were likely due to AA, because I was being fed a corn oil rich diet. I no longer have any of these conditions, after I changed my diet several years ago. |
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At least in snails the Mead acid seems to happily coexist with the "EFAs" till they are fed the vegetable oils:
Journal of Food Composition and Analysis
Volume 19, Issue 2-3, March 2006, Pages 212-216
Effects of feed protein and lipid contents on fatty acid profile of snail (Helix aspersa maxima) meat
Milinsk, M.C.a , das Graças Padre, R.a , Hayashi, C.b , de Oliveira, C.C.a , Visentainer, J.V.a , de Souza, N.E.a , Matsushita, M.a
a Department of Chemistry, State University of Maringá, Av. Colombo 5790, 87020-900 Maringa, Parana State, Brazil
b Department of Biology, State University of Maringá, Av. Colombo 5790, 87020-900 Maringa, Parana State, Brazil
The purpose of the present work is to verify the influence of different feed protein and lipid contents on the proximate composition on the fatty acid profile of snail meat (Helix aspersa maxima). The predominant fatty acids were palmitic (16.0), estearic (18:0), oleic (18:1 n-9), linoleic (18:2 n-6), mead (20:3 n-9), and arachidonic (20:4 n-6) acids. The reason of interest is that snail meat has n-6 and n-3 fatty acids with a chain length of 22 carbons (as 22:4 n6, 22:5 n6 and 22:5 n3). The results of this work revealed that snail meat (H. aspersa maxima) is a protein source with low lipid content that has with essential fatty acids in its composition (linoleic and linolenic acids) and polyunsaturated fatty acids with more than 20 C atoms, indicating that this food can be used for patient nutrition irrespective of total lipid content.
Food Chemistry
Volume 82, Issue 4, September 2003, Pages 553-558
Influence of diets enriched with different vegetable oils on the fatty acid profiles of snail Helix aspersa maxima
Milinsk, M.C.a , Das Graças Padre, R.a , Hayashi, C.b , De Souza, N.E.a , Matsushita, M.a
a Department of Chemistry, State University of Maringa, Av. Colombo, 5790, CEP 87020-900, Maringa, Parana State, Brazil
b Department of Biology, State University of Maringa, Av. Colombo, 5790, CEP 87020-900, Maringa, Parana State, Brazil
The proximate analyses and fatty acid profiles of snail (Helix aspersa maxima) muscle submitted to different feedings with diets enriched with 3% of different vegetable oils (canola, soybean, flaxseed, sunflower, maize and rice) were analysed. The lowest value of lipids was in the snail muscle of the treatment enriched with soybean oil. The main fatty acids detected were palmitic (C16:0), oleic (C18:1n9) and linoleic (LA, C18:2n6) in all treatments. The highest value for linolenic acid (LNA, C18:3n3) was observed in muscle of snail fed with enriched diet of flaxseed (oil also high in LNA). |
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