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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 8 of 8. This is the beginning of the thread.
Posted by IsoM on February 6, 2003, at 17:50:41
Larry, you seem pretty educated about the benefits of diff fatty acids. Do you have any links to reliable articles about CLAs? I'd like to read more about them that isn't from a commercial site, or pseudo-science fad sites. I'd appreciate it if you had anything reliable to share.
Posted by linkadge on February 6, 2003, at 18:10:25
In reply to Larry Hoover - Question about CLAs, posted by IsoM on February 6, 2003, at 17:50:41
I found personally that CLA had a strong calming and mood stabalizing effect. Almost slightly mood darkening. What have you noticed ?
Linkadge
Posted by missinglynxx on February 6, 2003, at 22:45:49
In reply to Re: Larry Hoover - Question about CLAs, posted by linkadge on February 6, 2003, at 18:10:25
> I found personally that CLA had a strong calming and mood stabalizing effect. Almost slightly mood darkening. What have you noticed ?
>
> LinkadgeReally linkadge thats interesting. Dont you hate when the advertise CLA as giving you dense firm muscles,and huge biceps!
I mean no nutrient expect protein would influence muscles...... Its so hard to separate the HYPE From Reality..////
Is CLA supposed to influence Brain Function?
Posted by IsoM on February 7, 2003, at 1:19:34
In reply to Re: Larry Hoover - Question about CLAs, posted by linkadge on February 6, 2003, at 18:10:25
I've never used CLA capsules, so I'm not looking to see what they may have done for me. Instead, I'm looking for genuine sources of organic meat with animals that are fed open range rather than typical feed & grain. I try to get as much as my nutrients from foods rather than pay mega-bucks for supplements that aren't always what they're cracked up to be.
CLAs are only found in any amount in the fat of animals that graze on grass. It's not just the brain boosting that interests me but over all health & benefits. I'm glad I never bought into the hype about fats years ago. I've never used margarine or shortening. It was butter or lard if I used anything. My intake of trans-fatty acids has been practically nil - don't like chips, don't eat french fries (maybe once every 2 years), or store-bought baked goods or crackers, etc.
I'm curious to read what's known about CLAs & figure Larry would probably have the most up-to-date info available.
Posted by Larry Hoover on February 7, 2003, at 9:06:48
In reply to ...that's why I'm asking Larry for articles..., posted by IsoM on February 7, 2003, at 1:19:34
> I've never used CLA capsules, so I'm not looking to see what they may have done for me. Instead, I'm looking for genuine sources of organic meat with animals that are fed open range rather than typical feed & grain. I try to get as much as my nutrients from foods rather than pay mega-bucks for supplements that aren't always what they're cracked up to be.
CLA supplements may actually be harmful, as there are many different isomers (28 I think) which would be randomly produced in man-made supplements. You're wise to focus on wholefood sources. If a CLA supplement is *extracted* from whole foods, that would be OK, but I don't know how you'd be able to tell that sort of product from one that is man-made. They could both be labelled "natural source", as the ALA in the man-made product would obviously come from vegetable oil. This is my biggest concern about CLA supplementation, and I admit that I haven't looked into finding a quality product yet.
> CLAs are only found in any amount in the fat of animals that graze on grass.
Actually, CLAs come from ruminants, cud-chewers. It's the lumen bacteria that produce the CLAs from partial hydrogenation of ALA. Beef, dairy cattle, sheep and lamb are the best sources. I believe that grass-feeding is an enhancement, but probably through co-ingestion of "weeds" like dandelion.
>It's not just the brain boosting that interests me but over all health & benefits. I'm glad I never bought into the hype about fats years ago. I've never used margarine or shortening. It was butter or lard if I used anything. My intake of trans-fatty acids has been practically nil - don't like chips, don't eat french fries (maybe once every 2 years), or store-bought baked goods or crackers, etc.
You're exceptional. <grin>
> I'm curious to read what's known about CLAs & figure Larry would probably have the most up-to-date info available.I appreciate the confidence you place in me. Here's the latest:
**This article links one specific CLA isomer, the trans-10, cis-12 one, to beneficial changes in energy-regulation in type-2 diabetes.
J Nutr 2003 Jan;133(1):257S-260S
The conjugated linoleic acid (CLA) isomer, t10c12-CLA, is inversely associated with changes in body weight and serum leptin in subjects with type 2 diabetes mellitus.Belury MA, Mahon A, Banni S.
Department of Human Nutrition, The Ohio State University, Columbus, USA. belury.1@osu.edu
Isomers of conjugated linoleic acid (CLA) are found in beef, lamb and dairy products. Diets containing CLA reduce adipose mass in various depots of experimental animals. In addition, CLA delays the onset of diabetes in the ZDF rat model for obesity-linked type 2 diabetes mellitus. We hypothesize that there would be an inverse association of CLA with body weight and serum leptin in subjects with type 2 diabetes mellitus. In this double-blind study, subjects with type 2 diabetes mellitus were randomized into one of two groups receiving either a supplement containing mixed CLA isomers (CLA-mix; 8.0 g daily, 76% pure CLA; n = 12) or a supplement containing safflower oil (placebo; 8.0 g daily safflower oil, n = 9) for 8 wk. The isomers of CLA in the CLA-mix supplement were primarily c9t11-CLA ( approximately 37%) and t10c12-CLA ( approximately 39%) in free fatty acid form. Plasma levels of CLA were inversely associated with body weight (P < 0.05) and serum leptin levels (P < 0.05). When levels of plasma t10c12-CLA isomer were correlated with changes in body weight or serum leptin, t10c12-CLA, but not c9t11-CLA, was inversely associated with body weights (P < 0.05) and serum leptin (P < 0.02). These findings strongly suggest that the t10c12-CLA isomer may be the bioactive isomer of CLA to influence the body weight changes observed in subjects with type 2 diabetes. Future studies are needed to determine a causal relationship, if any, of t10c12-CLA or c9t11-CLA to modulate body weight and composition in subjects with type 2 diabetes. Furthermore, determining the ability of CLA isomers to influence glucose and lipid metabolism as well as markers of insulin sensitivity is imperative to understanding the role of CLA to aid in the management of type 2 diabetes and other related conditions of insulin resistance.
**This one just says nice things about CLAs.Can J Appl Physiol 2002 Dec;27(6):617-28
Effects of Conjugated Linoleic Acid (CLA) on Immune Responses, Body Composition and Stearoyl-CoA Desaturase.
Ntambi JM, Choi Y, Park Y, Peters JM, Pariza MW.
Department of Biochemistry and Department of Nutritional Sciences, Food Research Institute, University of Wisconsin-Madison, WI.
Conjugated linoleic acid (CLA) has shown a wide range of biologically beneficial effects; reduction of incidence and severity of animal carcinogenesis, reduction of the adverse effects of immune stimulation, reduction of severity of atherosclerosis, growth promotion in young rats, and modulation of stearoyl-CoA desaturase (SCD). One of the most interesting aspects of CLA is its ability to reduce body fat while enhancing lean body mass which is associated with the trans-10,cis-12 isomer of CLA. The effects of CLA are unique characteristics that have not been observed with other polyunsaturated fatty acids. In this review, we will focus on the effects of CLA on immune responses, body compositional changes and stearoyl-CoA desaturase.
**This one shows that CLAs block inflammatory processes both at the enzyme level and at the gene-regulatory level.Clin Nutr 2002 Dec;21(6):451-9
Colonic anti-inflammatory mechanisms of conjugated linoleic acid.BASSAGANYA-RIERA J, HONTECILLAS R, BEITZ DC.
Department of Animal Sciences, Iowa State University, Ames, Iowa, USA
Conjugated linoleic acid (CLA) is a mixture of positional (e.g. 7,9; 9,11; 10,12; 11,13) and geometric (cis or trans) isomers of octadecadienoic acid. This compound was first shown to prevent mammary carcinogenesis in murine models. Later investigations uncovered a number of additional health benefits, including decreasing atherosclerosis and inflammation while enhancing immune function. The mechanisms of action underlying these biological properties are not clearly understood. The aim of this review is to highlight recent advances in CLA research related to experimental inflammatory bowel disease. In addition, two possible mechanisms of action (i.e. endoplasmic and nuclear) were discussed in detail in the context of enteric inflammatory disorders. Conjugated linoleic acid was first implicated in down-regulating the generation of inducible eicosanoids (i.e. PGE(2) and LTB(4)) involved in early micro-inflammatory events (endoplasmic). More recently, CLA has been shown to modulate the expression of genes regulated by peroxisome proliferator-activated receptors (PPARs; nuclear). In pigs, prolonged dietary CLA treatment stimulated the expression of PPAR-gamma in the muscle. Thus, evidence supporting both mechanistic theories of CLA acting through eicosanoid synthesis and PPAR activity is available. The further understanding of the anti-inflammatory mechanisms of action of CLA may yield novel nutritional therapies for enteric inflammation.
**This one provides evidence that CLAs are *bad*, with respect to heart disease risk factors and insulin/glucose regulation. (Gotta consider everything.)
Circulation 2002 Oct 8;106(15):1925-9
Supplementation with conjugated linoleic acid causes isomer-dependent oxidative stress and elevated C-reactive protein: a potential link to fatty acid-induced insulin resistance.
Riserus U, Basu S, Jovinge S, Fredrikson GN, Arnlov J, Vessby B.Department of Public Health and Caring Sciences/Geriatrics, Uppsala University, Uppsala, Sweden. ulf.riserus@pubcare.uu.se
BACKGROUND: Conjugated linoleic acids (CLAs), a group of fatty acids shown to have beneficial effects in animals, are also used as weight loss supplements. Recently, we reported that the t10c12 CLA-isomer caused insulin resistance in abdominally obese men via unknown mechanisms. The aim of the present study was to examine whether CLA has isomer-specific effects on oxidative stress or inflammatory biomarkers and to investigate the relationship between these factors and induced insulin resistance. METHODS AND RESULTS: In a double-blind placebo-controlled trial, 60 men with metabolic syndrome were randomized to one of 3 groups receiving t10c12 CLA, a CLA mixture, or placebo for 12 weeks. Insulin sensitivity (euglycemic clamp), serum lipids, in vivo lipid peroxidation (determined as urinary 8-iso-PGF(2alpha) [F2-isoprostanes]), 15-ketodihydro PGF(2alpha), plasma vitamin E, plasma C-reactive protein, tumor necrosis factor-alpha, and interleukin-6 were assessed before and after treatment. Supplementation with t10c12 CLA markedly increased 8-iso-PGF(2alpha) (578%) and C-reactive protein (110%) compared with placebo (P<0.0001 and P<0.01, respectively) and independent of changes in hyperglycemia or dyslipidemia. The increases in 8-iso-PGF(2alpha), but not in C-reactive protein, were significantly and independently related to aggravated insulin resistance. Oxidative stress was related to increased vitamin E levels, suggesting a compensatory mechanism. CONCLUSIONS: t10c12 CLA supplementation increases oxidative stress and inflammatory biomarkers in obese men. The oxidative stress seems closely related to induced insulin resistance, suggesting a link between the fatty acid-induced lipid peroxidation seen in the present study and insulin resistance. These unfavorable effects of t10c12 CLA might be of clinical importance with regard to cardiovascular disease, in consideration of the widespread use of dietary supplements containing this fatty acid.
**This one discusses the anti-cancer effects of CLAs.J Nutr 2002 Oct;132(10):2995-8
Inhibition of carcinogenesis by conjugated linoleic acid: potential mechanisms of action.Belury MA.
Department of Molecular Medicine, Northwest Hospital, Bothell, WA 98021, USA. Belury@u.washington.edu
Conjugated linoleic acid (CLA) is composed of positional and stereoisomers of octadecadienoate (18:2); it is found in foods derived from ruminants (beef and lamb as well as dairy products from these sources). When a mixture of isomers is fed to experimental animals, chemically induced tumorigenesis of mammary, skin and colon is reduced. Importantly, many isomers of CLA are readily metabolized to desaturated/elongated products as well as beta-oxidized products, suggesting that these metabolites may be important anticancer compounds. Mechanisms of inhibition of carcinogenesis may include reduction of cell proliferation, alterations in the components of the cell cycle and induction of apoptosis. In addition, CLA modulates markers of immunity and eicosanoid formation in numerous species as well as lipid metabolism and gene expression. It is likely that CLA exerts inhibitory properties in carcinogenesis via one or more of these pathways with some tissue specificity. This review will explore recent advances in putative mechanisms of reduction of carcinogenesis by CLA.
Posted by Larry Hoover on February 7, 2003, at 9:40:06
In reply to Re: Larry Hoover - Question about CLAs, posted by missinglynxx on February 6, 2003, at 22:45:49
> Really linkadge thats interesting. Dont you hate when the advertise CLA as giving you dense firm muscles,and huge biceps!
> I mean no nutrient expect protein would influence muscles...... Its so hard to separate the HYPE From Reality..////
> Is CLA supposed to influence Brain Function?Actually, CLA is linked to increases in the ratio of lean body mass/fat storage, both in man and laboratory animals.
Lar
Posted by IsoM on February 20, 2003, at 2:06:41
Larry, I'm reposting here in case you missed the archived post for you.
This is to do with the abstracts on CLA. You mentioned that lab produced CLAs would have a higher proportion of c9t11-CLA & t10c12-CLA as opposed to what occurs naturally in the fat of ruminants.
But in the abstracts, when studies were done on possible benefits, what CLAs were used for these studies? It seems to imply that the man-made isomer mixes were used, not extracts from the fat of the ruminants. I found quite a few more abstracts on CLAs but in all of them, it implies or directly states that the CLAs used were the supplemental ones sold. Do you want to clarify anything about this as I'm curious to what was used & how that would compare to the actual fat of grass-grazed ruminants. Does that change any of the results of the studies & what they'd be like if actual fat was used instead?
Got a few more questions -
1. The newer methods that labs use now to separate racemic mixtures in lab synthesized compounds (like thalidomide) - can these methods (or similar ones) be used in separating isomers of fatty acids? And if they can be used, are they actually in use or is the method still prohibitory expensive?2. What exactly is done in the labs to ordinary sunflower oil (or other polyunsaturated ones) to make CLAs? What's the method?
3. Considering what's done with the excess of beef tallow in the food industry, would it be feasible for labs to extract the CLAs from beef fat rather than synthesize it from vegetable oils?
4. As I said earlier, I prefer to get mine from real food, but is the high price of CLA supplements justified by the cost of production?
5. Is there much difference that you know of in the fatty acids of pork & chicken fat between those factory produced animals & those raised "free range"? I know the fatty acids of eggs show a difference. I'm curious as pork & chicken fat is much less solid than beef & sheep (lamb) fat at room temperature.
6. And finally - the values used in the USDA sites of nutrient breakdown - these would all be the averages, I assume, so they'd be the values from that of factory produced animals. Am I correct?
As an extra for you about taurine - I wondered why cat food needs to have taurine added to the food. I knew that cats have a higher requirement of taurine than most animals. If it had to be added, I wondered where they would've got it from before pet foods had it added. Did some checking & comparing, & found some of the highest levels of taurine are found in rodents. If I wouldn't be grossed out skinning the little beggars, I'd add them to the meat mix I use in making my cats' home-made food. I'm not at all squeamish but that's going a bit too far. I buy it as a powder & add it instead. Humans get plenty in their foods if they get enough protein, correct?
Posted by Larry Hoover on February 22, 2003, at 10:52:43
In reply to Larry Hoover - about CLA Abstracts and taurine, posted by IsoM on February 20, 2003, at 2:06:41
> Larry, I'm reposting here in case you missed the archived post for you.
>
> This is to do with the abstracts on CLA. You mentioned that lab produced CLAs would have a higher proportion of c9t11-CLA & t10c12-CLA as opposed to what occurs naturally in the fat of ruminants.I'm not sure what I said before, but I've spent some time researching this further, as my opinions were somewhat coloured by inference.
What is clear to me now is that the dominant CLA isomer in ruminant food products is the c9t11 isomer (85%, more or less); only synthetic products have a substantial amount of the t10c12 isomer. It is now apparent that the isomer that enhances lean/adipose ratios is the latter, synthetic isomer.
> But in the abstracts, when studies were done on possible benefits, what CLAs were used for these studies? It seems to imply that the man-made isomer mixes were used, not extracts from the fat of the ruminants. I found quite a few more abstracts on CLAs but in all of them, it implies or directly states that the CLAs used were the supplemental ones sold. Do you want to clarify anything about this as I'm curious to what was used & how that would compare to the actual fat of grass-grazed ruminants. Does that change any of the results of the studies & what they'd be like if actual fat was used instead?
Isolating CLA from natural food products is much more costly (prohibitively so) than synthesizing CLA via base-catalyzed isomerization. The problem (if it is one) with the latter process is that is so non-specific that many "unnatural" isomers are produced as well. The health effects of the latter are of some concern, but as revealed in these following references, there are high-quality products on the market which are virtually pure c9t11-CLA & t10c12-CLA.
http://www.lipid.co.uk/infores/others/claintro.html
http://www.lipid.co.uk/infores/topics/cla/file.pdf
http://www.britanniafood.com/german/invite_08.htm
> Got a few more questions -
> 1. The newer methods that labs use now to separate racemic mixtures in lab synthesized compounds (like thalidomide) - can these methods (or similar ones) be used in separating isomers of fatty acids? And if they can be used, are they actually in use or is the method still prohibitory expensive?Fatty acids are not chiral, so there are no racemates. So called physico-chemical processes can separate fatty acids, e.g. distillation. Chromatography also works, but it is not practical for bulk samples.
> 2. What exactly is done in the labs to ordinary sunflower oil (or other polyunsaturated ones) to make CLAs? What's the method?The fatty acids are exposed to base (e.g. potassium hydroxide). There is an addition-elimination reaction which either produces the parent compound again, or a positional isomer of the parent (it's a statistical process). As the product of the isomerization can further isomerize, other products begin to grow in concentration as time goes on. At some point, an equilibrium would occur, but the process would likely be stopped when "primary" isomers predominate, and secondary ones had not yet had much chance to increase in concentration.
> 3. Considering what's done with the excess of beef tallow in the food industry, would it be feasible for labs to extract the CLAs from beef fat rather than synthesize it from vegetable oils?
As it stands now, the PUFAs are saturated via hydrogenation, and there aren't any such by-products.
> 4. As I said earlier, I prefer to get mine from real food, but is the high price of CLA supplements justified by the cost of production?Yes, it's a costly process. Is it a justifiable price? Probably not.
> 5. Is there much difference that you know of in the fatty acids of pork & chicken fat between those factory produced animals & those raised "free range"?Substantial difference. Most of the difference is in the PUFAs.
>I know the fatty acids of eggs show a difference. I'm curious as pork & chicken fat is much less solid than beef & sheep (lamb) fat at room temperature.
That has much to do with what the liver does with excess calories than anything else. Each species has a dominant storage fatty acid(s), and that's what determines the melting point of the adipose fat.
> 6. And finally - the values used in the USDA sites of nutrient breakdown - these would all be the averages, I assume, so they'd be the values from that of factory produced animals. Am I correct?You can be certain those are from factory animals.
(My assumption).> As an extra for you about taurine - I wondered why cat food needs to have taurine added to the food. I knew that cats have a higher requirement of taurine than most animals. If it had to be added, I wondered where they would've got it from before pet foods had it added. Did some checking & comparing, & found some of the highest levels of taurine are found in rodents. If I wouldn't be grossed out skinning the little beggars, I'd add them to the meat mix I use in making my cats' home-made food. I'm not at all squeamish but that's going a bit too far. I buy it as a powder & add it instead. Humans get plenty in their foods if they get enough protein, correct?
Cats are obligate taurine consumers; they've lost the capacity to synthesize it, just like we've lost the capacity to synthesize vitamin C. From an evolutionary stand-point, the loss of the enzyme to create taurine is of no consequence as kitties eat lots of rodents, unless we prevent their access to same, and provide them inadequate dietary content as a replacement.
This is the end of the thread.
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