The Dangers of CLA Supplementation

I thought the Cis 11 Trans 9 Isomer was the one that is touted. This study seems to say the opposite:

Adipose depletion and apoptosis induced by trans-10, cis-12 conjugated linoleic Acid in mice.

Hargrave KM, Li C, Meyer BJ, Kachman SD, Hartzell DL, Della-Fera MA, Miner JL, Baile CA.

Department of Animal Science, University of Nebraska, Lincoln, USA.

OBJECTIVE: To compare the effectiveness of a conjugated linoleic acid (CLA) isomer mixture (mCLA) with each main isomer [trans-10,cis-12 CLA (CLA10,12) and cis-9,trans-11 CLA (CLA9,11)] in causing body lipid loss and adipose tissue apoptosis. RESEARCH METHODS AND PROCEDURES: Mice selected over 16 generations for high (MH) or low (ML) energy expenditure and a control group (MC) were fed diets containing either soy oil or soy oil plus mCLA, CLA10,12, or CLA9,11 for 5 days in one study and 14 days in a second study. RESULTS: Mice fed mCLA or CLA10,12 had less body lipid (p < 0.05), smaller retroperitoneal fat pads (p < 0.05), and ate less (p < 0.01) than mice fed no CLA or CLA9,11 for 5 days. Mice consuming 1% mCLA or 0.5% CLA10,12 gained less weight (p < 0.01) and had less body lipid (p < 0.05) and smaller epididymal (p < 0.05) and retroperitoneal fat pads (p < 0.01) than mice consuming either control or 0.5% CLA9,11-containing diets for 14 days. Only mCLA and CLA10,12 increased apoptosis in retroperitoneal fat pads (p < 0.01). The effects of mCLA and CLA10,12 were independent of genetic line except for the effect on adipocyte apoptosis. Mice of the MH line were slightly less sensitive than MC or ML mice to CLA-induced adipose tissue apoptosis. DISCUSSION: CLA10,12, but not CLA9,11, can induce both body fat loss and adipose apoptosis. Although mice of a genotype with less body fat and greater metabolic rate and feed intake appear less sensitive, these CLA effects are robust for mice of varying metabolic background.

Yea, it's the trans-10, cis-12 isomer that has been proposed to have fatloss effects in animals.

quote:

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J Lipid Res. 2003 Jul;44(7):1287-300. Epub 2003 May 01.

Isomer-specific regulation of metabolism and PPARgamma signaling by CLA in human preadipocytes.

Brown JM, Boysen MS, Jensen SS, Morrison RF, Storkson J, Lea-Currie R, Pariza M, Mandrup S, McIntosh MK.

Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC 27402-6170, USA.

Trans-10,cis-12 conjugated linoleic acid (CLA) has previously been shown to be the CLA isomer responsible for CLA-induced reductions in body fat in animal models, and we have shown that this isomer, but not the cis-9,trans-11 CLA isomer, specifically decreased triglyceride (TG) accumulation in primary human adipocytes in vitro. Here we investigated the mechanism behind the isomer-specific, CLA-mediated reduction in TG accumulation in differentiating human preadipocytes. Trans-10,cis-12 CLA decreased insulin-stimulated glucose uptake and oxidation, and reduced insulin-dependent glucose transporter 4 gene expression. Furthermore, trans-10,cis-12 CLA reduced oleic acid uptake and oxidation when compared with all other treatments. In parallel to CLA's effects on metabolism, trans-10,cis-12 CLA decreased, whereas cis-9,trans-11 CLA increased, the expression of peroxisome proliferator-activated receptor gamma (PPARgamma) and several of its downstream target genes when compared with vehicle controls. Transient transfections demonstrated that both CLA isomers antagonized ligand-dependent activation of PPARgamma. Collectively, trans-10,cis-12, but not cis-9, trans-11, CLA decreased glucose and lipid uptake and oxidation and preadipocyte differentiation by altering preadipocyte gene transcription in a manner that appeared to be due, in part, to decreased PPARgamma expression.

PMID: 12730300

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I thought the Cis 11 Trans 9 Isomer was the one that is touted

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Really, both are touted, depending on the focus of the literature. The Life Extensionists praise the 9,11 isomer for its reputed anticancer effects, while bodybuilders seek out the fat burning effects of the other isomer reported in some studies. So CLA enthusiasts generally go for a mix (Tonalin) to get both effects.

I had read a lot of the pros and cons of CLA but had not seen the increase in C reactive protein noted before. The review also mentioned that humans given CLA showed significantly elevated levels of a couple of markers of lipid peroxidation. These latter effects are not too surprising if one considers that chemically CLA is classified as a trans-fatty acid, which as most people know, are not supposed to be too healthful.

With most supplements the issue seems to be whether they simply work or not. With CLA there do seem to be health considerations as well.

Posted by: Nandi12

The review also mentioned that humans given CLA showed significantly elevated levels of a couple of markers of lipid peroxidation.

I know that Tea Catechins have been shown to protect against lipid peroxidation in a variety of different cells in vitro. If they do they same in vivo that might take care of that concern.

The question I had was what does the cla-induced liver hypertrophy mean and what are the consquences?

To my knowledge the effects of CLA on the liver have not been examined in humans. The authors are expressing their concerns based on animal studies that have shown CLA induces liver hypertrophy and steatosis (fatty liver). Steatosis can lead to fibosis and cirrhosis. But mice exhibit fat loss when given CLA, unlike humans (at least in most studies, according to the review), so it's not clear whether CLA actually leads to steatosis in people. There just aren't any studies.

'clinical' data from a wide pool of participants seems to suggest that indeed CLA particularly when combined with ALA or R-ALA and Alcar (and GTex w/high EGCG) absolutley has a positive effect on body composition

these trials used a pool of healthy active weigth training males and the predominant results in the group were of a highly favorable nature

one can go to lab resarch or such and get conflicting views/results observed, but i think this trial may be more definitive related to the interest of most here

entered obesity and CLA on google first two studies.

http://www.ncbi.nlm.nih.gov/entrez/...7&dopt;=Abstract

http://www.ncbi.nlm.nih.gov/entrez/...7&dopt;=Abstract

onjugated linoleic acid supplementation in humans--metabolic effects.

http://www.ncbi.nlm.nih.gov:80/entr...7&dopt;=Abstract

Posted by: wheycasein

entered obesity and CLA on google first two studies.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11477497&dopt=Abstrac t" target="_blank" rel="noopener"> http://www.ncbi.nlm.nih.gov/entrez/...7&dopt;=Abstract

Conjugated linoleic acid (CLA) reduced abdominal adipose tissue in obese middle-aged men with signs of the metabolic syndrome: a randomised controlled trial.

Riserus U, Berglund L, Vessby B.

Clinical Nutrition Research Unit, Department of Public Health and Caring Sciences/Geriatrics, Faculty of Medicine, Uppsala University, Uppsala, Sweden. [email protected]

BACKGROUND: Abdominal obesity is strongly related to metabolic disorders. Recent research suggests that dietary conjugated linoleic acid (CLA) reduces body fat and may improve metabolic variables in animals. The metabolic effects of CLA in abdominally obese humans have not yet been tested. OBJECTIVE: To investigate the short-term effect of CLA on abdominal fat and cardiovascular risk factors in middle-aged men with metabolic disorders. METHODS: Twenty-five abdominally obese men (waist-to-hip ratio (WHR), 1.05+/-0.05; body mass index (BMI), 32+/-2.7 kg/m(2) (mean+/-s.d.)) who were between 39 and 64-y-old participated in a double-blind randomised controlled trial for 4 weeks. Fourteen men received 4.2 g CLA/day and 10 men received a placebo. The main endpoints were differences between the two groups in sagittal abdominal diameter (SAD), serum cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, free fatty acids, glucose and insulin. RESULTS: At baseline, there were no significant differences between groups in anthropometric or metabolic variables. After 4 weeks there was a significant decrease in SAD (cm) in the CLA group compared to placebo (P=0.04, 95% CI; -1.12, -0.02). Other measurements of anthropometry or metabolism showed no significant differences between the groups. CONCLUSIONS: These results indicate that CLA supplementation for 4 weeks in obese men with the metabolic syndrome may decrease abdominal fat, without concomitant effects on overall obesity or other cardiovascular risk factors. Because of the limited sample size, the effects of CLA in abdominal obesity need to be further investigated in larger trials with longer duration.

Posted by: wheycasein

entered obesity and CLA on google first two studies.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11477497&dopt=Abstrac t" target="_blank" rel="noopener"> http://www.ncbi.nlm.nih.gov/entrez/...7&dopt;=Abstract

Conjugated linoleic acid (CLA) reduced abdominal adipose tissue in obese middle-aged men with signs of the metabolic syndrome: a randomised controlled trial.

Riserus U, Berglund L, Vessby B.

Clinical Nutrition Research Unit, Department of Public Health and Caring Sciences/Geriatrics, Faculty of Medicine, Uppsala University, Uppsala, Sweden. [email protected]

BACKGROUND: Abdominal obesity is strongly related to metabolic disorders. Recent research suggests that dietary conjugated linoleic acid (CLA) reduces body fat and may improve metabolic variables in animals. The metabolic effects of CLA in abdominally obese humans have not yet been tested. OBJECTIVE: To investigate the short-term effect of CLA on abdominal fat and cardiovascular risk factors in middle-aged men with metabolic disorders. METHODS: Twenty-five abdominally obese men (waist-to-hip ratio (WHR), 1.05+/-0.05; body mass index (BMI), 32+/-2.7 kg/m(2) (mean+/-s.d.)) who were between 39 and 64-y-old participated in a double-blind randomised controlled trial for 4 weeks. Fourteen men received 4.2 g CLA/day and 10 men received a placebo. The main endpoints were differences between the two groups in sagittal abdominal diameter (SAD), serum cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, free fatty acids, glucose and insulin. RESULTS: At baseline, there were no significant differences between groups in anthropometric or metabolic variables. After 4 weeks there was a significant decrease in SAD (cm) in the CLA group compared to placebo (P=0.04, 95% CI; -1.12, -0.02). Other measurements of anthropometry or metabolism showed no significant differences between the groups. CONCLUSIONS: These results indicate that CLA supplementation for 4 weeks in obese men with the metabolic syndrome may decrease abdominal fat, without concomitant effects on overall obesity or other cardiovascular risk factors. Because of the limited sample size, the effects of CLA in abdominal obesity need to be further investigated in larger trials with longer duration.

Posted by: wheycasein

onjugated linoleic acid supplementation in humans--metabolic effects.

http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11592727&dopt=Abstrac t" target="_blank" rel="noopener"> http://www.ncbi.nlm.nih.gov:80/entr...7&dopt;=Abstract

Conjugated linoleic acid supplementation in humans--metabolic effects.

Smedman A, Vessby B.

Department of Public Health and Caring Sciences/Geriatrics, Uppsala University, Sweden. [email protected]

Supplementation with conjugated linoleic acid (CLA) induces a number of physiological effects in experimental animals, including reduced body fat content, decreased aortic lipid deposition, and improved serum lipid profile. Controlled trials on the effects of CLA in humans have hitherto been scarce. The aim of this study was to evaluate the effects of supplementation with CLA in healthy humans on anthropometric and metabolic variables and on the fatty acid composition of serum lipids and thrombocytes. Fifty-three healthy men and women, aged 23-63 yr, were randomly assigned to supplementation with CLA (4.2 g/d) or the same amount of olive oil during 12 wk in a double-blind fashion. The proportion of body fat decreased (-3.8%, P< 0.001) in the CLA-treated group, with a significant difference from the control group (P = 0.050). Body weight, body mass index, and sagittal abdominal diameter were unchanged. There were no major differences between the groups in serum lipoproteins, nonesterified fatty acids, plasma insulin, blood glucose, or plasminogen activator inhibitor 1 (PAI-1). In the CLA group the proportions of stearic, docosatetraenoic, and docosapentaenoic acids increased in serum lipids and thrombocytes, while proportions of palmitic, oleic, and dihomo-gamma-linolenic acids decreased, causing a decrease of the estimated delta-6 and delta-9 and an increase in the delta-5 desaturase activities. These results suggest that supplementation with CLA may reduce the proportion of body fat in humans and that CLA affects fatty acid metabolism. No effects on body weight, serum lipids, glucose metabolism, or PAI-1 were seen.