title: Effects of the individual isomers cis-9,trans-11 vs. trans-10,cis-12 of conjugated linoleic acid (CLA) on inflammation parameters in moderately overweight subjects with LDL-phenotype B Supplementation with conjugated linoleic acid for 24 months is well tolerated by and reduces body fat mass in healthy, overweight humans. Study of the effect of trans fatty acids from ruminants on blood lipids and other risk factors for cardiovascular disease. An oil mixture with trans-10, cis-12 conjugated linoleic acid increases markers of inflammation and in vivo lipid peroxidation compared with cis-9, trans-11 conjugated linoleic acid in postmenopausal women. Effects of cis-9,trans-11 and trans-10,cis-12 conjugated linoleic acid on immune cell function in healthy humans. Conjugated linoleic acid reduces body fat mass in overweight and obese humans. Conjugated linoleic acid supplementation for twelve weeks increases lean body mass in obese humans. Conjugated linoleic acid supplementation for 1 y reduces body fat mass in healthy overweight humans. Dietary supplementation with cis-9,trans-11 conjugated linoleic acid and aortic stiffness in overweight and obese adults. Effects of milk supplementation with conjugated linoleic acid on weight control and body composition in healthy overweight people. A high intake of trans fatty acids has little effect on markers of inflammation and oxidative stress in humans. Cis-9, trans- 11 and trans-10, cis-12 conjugated linoleic acid (CLA) do not affect the plasma lipoprotein profile in moderately overweight subjects with LDL phenotype B. Conjugated Linoleic Acid Impairs Endothelial Function Creatine Monohydrate and Conjugated Linoleic Acid Improve Strength and Body Composition Following Resistance Exercise in Older Adults Six months supplementation with conjugated linoleic acid induces regional-specific fat mass decreases in overweight and obese. Effects of conjugated linoleic acid plus n-3 polyunsaturated fatty acids on insulin secretion and estimated insulin sensitivity in men The role of conjugated linoleic acid in reducing body fat and preventing holiday weight gain Effects of conjugated linoleic acid supplementation on blood lipids and adiposity of rats fed diets rich in saturated versus unsaturated fat. Conjugated linoleic acids reduce body fat in healthy postmenopausal women. Lipoprotein(a) as a risk factor for cardiovascular mortality in type 2 diabetic patients: a 10-year follow-up study. CLA Does Not Impair Endothelial Function and Decreases Body Weight as Compared with Safflower Oil in Overweight and Obese Male Subjects Conjugated linoleic acid induces lipid peroxidation in humans
abstract: Immune-modulating effects of CLA have been reported in animals , but results are inconsistent . In humans , CLA has shown no effects or only minor effects on immune function . The objective of this study was to evaluate the immune-modulating effects of 3 g cis-9,trans-11 ( c9,t11 ) vs. trans-10,cis-12 ( t10,c12 ) CLA isomers in a population with a high risk of coronary heart disease characterized by moderate overweight ( body-mass index , 25–32.5 kg/m2 ) in combination with LDL-phenotype B ( ≥35 % small LDL cholesterol , density≥1.040 g/mL ) . After a run-in period of 1 wk , 42 men and women were r and omly allocated to the c9,t11 CLA group , the t10,c12 CLA group , or the placebo group . Effects of 13 wk of consumption of 3 g of CLA isomers on cytokine production by ex vivo lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells ( P BMC ) and whole blood , and on plasma C-remononuclear protein ( CRP ) concentrations were evaluated . To generate hypotheses for future studies , protein expression patterns of 42 cytokines , chemokines , and growth factors were evaluated with an antibody array in pooled , nonstimulated , fasting plasma sample s. LPS induced interleukin (IL)-6 , IL-8 , and tumor necrosis factor-α production by P BMC , and whole blood as well as plasma CRP concentrations were not significantly changed by the c9,t11 , and the t10,c12 CLA isomers . The cytokine expression profile in nonstimulated plasma suggested that both CLA isomers induced a specific inflammatory signature , in which the c9,t11 CLA group showed more activity in terms of numbers of proteins regulated . We conclude that daily consumption of 3 g of c9,t11 or t10,c12 CLA isomer did not affect LPS-stimulated cytokine production by P BMC or whole blood and plasma CRP levels . Inflammatory signatures in fasting , nonstimulated plasma as determined by an antibody array may indicate enhanced immune function by both CLA isomers After 12 mo in a r and omized , double-blind , placebo-controlled trial of conjugated linoleic acid ( CLA ) supplementation ( 2 groups received CLA as part of a triglyceride or as the free fatty acid , and 1 group received olive oil as placebo ) , 134 of the 157 participants who concluded the study were included in an open study for another 12 mo . The goals of the extension study were to evaluate the safety [ with clinical chemistry analyses and reported adverse events ( AEs ) ] and assess the effects of  CLA on body composition [ body fat mass ( BFM ) , lean body mass ( LBM ) , bone mineral mass ( BMM ) ] , body weight , and BMI . All subjects were supplemented with 3.4 g CLA/d in the triglyceride form . Circulating lipoprotein(a ) and thrombocytes increased in all groups . There was no change in fasting blood glucose . Aspartate amino transferase , but not alanine amino transferase , increased significantly . Plasma total cholesterol and LDL cholesterol were reduced , whereas HDL cholesterol and triglycerides were unchanged . The AE rate decreased compared with the first 12 mo of the study . Body weight and BFM were reduced in the subjects administered the placebo during the initial 12 mo study ( -1.6 + /- 3.2 and -1.7 + /- 2.8 kg , respectively ) . No fat or body weight changes occurred in the 2 groups given CLA during the initial 12 mo . LBM and BMM were not affected in any of the groups . Changes in body composition were not related to diet and /or training . In conclusion , this study shows that CLA supplementation for 24 mo in healthy , overweight adults was well tolerated . It confirms also that CLA decreases BFM in overweight humans , and may help maintain initial reductions in BFM and weight in the long term BACKGROUND The intake of trans fatty acids ( TFA ) from industrially hydrogenated vegetable oils ( iTFA ) is known to have a deleterious effect on cardiovascular health , the effects of TFA from ruminants ( rTFA ) are virtually unknown . OBJECTIVE The purpose of the present study was to compare the effects of rTFA and iTFA on plasma LDL concentrations and other cardiovascular disease risk factors in healthy subjects . DESIGN In a double-blind , r and omized crossover controlled study , 38 healthy men were fed each of 4 experimental isoenergetic diets lasting 4 wk each . The 4 diets were high in rTFA ( 10.2 g/2500 kcal ) , moderate in rTFA ( 4.2 g/2500 kcal ) , high in iTFA ( 10.2 g/2500 kcal ) , and low in TFA from any source ( 2.2 g/2500 kcal ) ( control diet ) . RESULTS Plasma LDL-cholesterol concentrations were significantly higher after the high- rTFA diet than after the control ( P = 0.03 ) or the moderate- rTFA ( P = 0.002 ) diet . Plasma LDL-cholesterol concentrations also were significantly ( P = 0.02 ) higher after the iTFA diet than after the moderate-rTFA diet . Plasma HDL-cholesterol concentrations were significantly ( P = 0.02 ) lower after the high-rTFA diet than after the moderate-rTFA diet . Finally , all risk factors were comparable between the control and the moderate-rTFA diets . CONCLUSIONS These results suggest that , whereas a high dietary intake of TFA from ruminants may adversely affect cholesterol homeostasis , moderate intakes of rTFA that are well above the upper limit of current human consumption have neutral effects on plasma lipids and other cardiovascular disease risk factors A mixture of trans-10 , cis-12 ( t10,c12 ) and cis-9 , trans-11 ( c9,t11 ) conjugated linoleic acid ( CLA mixture ) reduced atherosclerosis in animals , thus the effect of these isomers on endothelial dysfunctions leading to inflammation and atherosclerosis is of interest . We gave 75 healthy postmenopausal women a daily supplement of 5.5 g of oil rich in either CLA mixture , an oil rich in the naturally occurring c9,t11 CLA ( CLA milk ) , respectively , or olive oil for 16 wk in a double-blind , r and omized , parallel intervention study . We sample d blood and urine before and after the intervention . The ratios of total cholesterol : HDL cholesterol and concentrations of C-reactive protein , fibrinogen , and plasminogen activator inhibitor-1 were significantly higher in women supplemented with the CLA mixture than in those supplemented with CLA milk .  Plasma triacylglycerol was significantly higher and HDL cholesterol was lower in women supplemented with the CLA mixture than with olive oil . Both CLA supplements increased lipid peroxidation , a marker of in vivo oxidative stress measured as urinary free 8-iso-prostagl and in F(2alpha ) . However , the CLA mixture increased lipid peroxidation more than the CLA milk did . The plasma cytokines interleukin-6 and tumor necrosis factor-alpha were not affected by the treatments , nor were any of the other variables measured . In conclusion , oil containing trans-10,cis-12 CLA has several adverse effects on classical and novel markers of coronary vascular disease , whereas the c9,t11 CLA isomer is more neutral , except for a small but significant increase in lipid peroxidation compared with olive oil BACKGROUND Animal studies have suggested that conjugated linoleic acid ( CLA ) , a natural component of ruminant meat and dairy products , may confer beneficial effects on health . However , little information on the effects of CLA on immune function is available , especially in humans . Furthermore , the effects of individual isomers of CLA have not been adequately investigated . OBJECTIVE This study investigated the effects of supplementing the diet with 3 doses of highly enriched cis-9,trans-11 CLA ( 0.59 , 1.19 , and 2.38 g/d ) or trans-10,cis-12 CLA ( 0.63 , 1.26 , and 2.52 g/d ) on immune outcomes in healthy humans . DESIGN The study had a r and omized , double-blind , crossover design . Healthy men consumed 1 , 2 , and 4 capsules sequentially that contained 80 % of either cis-9,trans-11 CLA or trans-10,cis-12 CLA for consecutive 8-wk periods . This regimen was followed by a 6-wk washout and a crossover to the other isomer . RESULTS Both CLA isomers decreased mitogen-induced T lymphocyte activation in a dose-dependent manner . There was a significant negative correlation between mitogen-induced T lymphocyte activation and the proportions of both cis-9,trans-11 CLA and trans-10,cis-12 CLA in peripheral blood mononuclear cell lipids . However , CLA did not affect lymphocyte sub population s or serum concentrations of C-reactive protein and did not have any consistent effects on ex vivo cytokine production . CONCLUSION CLA supplementation results in a dose-dependent reduction in the mitogen-induced activation of T lymphocytes . The effects of cis-9,trans-11 CLA and trans-10,cis-12 CLA were similar , and there was a negative correlation between mitogen-induced T lymphocyte activation and the cis-9,trans-11 CLA and trans-10,cis-12 CLA contents of mononuclear cells Conjugated linoleic acid ( CLA ) has been shown to reduce body fat mass ( BFM ) in animals . To investigate the dose-response relationships of conjugated linoleic acid with regard to BFM in humans , a r and omized , double-blind study including 60 overweight or obese volunteers ( body mass index 25 - 35 kg/m(2 ) ) was performed . The subjects were divided into five groups receiving placebo ( 9 g olive oil ) , 1.7 , 3.4 , 5.1 or 6.8 g conjugated linoleic acid per day for 12 wk , respectively . Dual-energy X-ray absorptiometry was used to measure body composition [ measurements at wk 0 ( baseline ) , 6 and 12 ] . Of the 60 subjects , 47 completed the study . Eight subjects withdrew from the study due to adverse events ; however , no differences among treatment groups were found regarding adverse events . Repeated- measures analysis showed that a significantly higher reduction in BFM was found in the conjugated linoleic acid groups compared with the placebo group ( P : = 0.03 ) . The reduction of body fat within the groups was significant for the 3.4 and 6.8 g CLA groups ( P : = 0.05 and P : = 0.02 , respectively ) . No significant differences among the groups were observed in lean body mass , body mass index , blood safety variables or blood lipids . The data suggest that conjugated linoleic acid may reduce BFM in humans and that no additional effect on BFM is achieved with doses > 3.4 g CLA/d Conjugated linoleic acid ( CLA ) alters body composition in animal models , but few studies have examined the effects of CLA supplementation on body composition and clinical safety measures in obese humans . In the present study , we performed a r and omized , double-blind , placebo-controlled trial to examine the changes in body composition and clinical laboratory values following CLA ( 50:50 ratio of cis-9 , trans-11 and trans-10 , cis-12 isomers ) supplementation for 12 wk in otherwise healthy obese humans . Forty-eight participants ( 13 males and 35 females ) were r and omized to receive placebo ( 8 g safflower oil/d ) , 3.2 g/d CLA , or 6.4 g/d CLA for 12 wk . Changes in body fat mass and lean body mass were determined by dual-energy X-ray absorptiometry . Resting energy expenditure was assessed by indirect calorimetry . Clinical laboratory values and adverse-event reporting were used to monitor safety . Lean body mass increased by 0.64 kg in the 6.4 g/d CLA group ( P < 0.05 ) after 12 wk of intervention . Significant decreases in serum HDL-cholesterol and sodium , hemoglobin , and hematocrit , and significant increases in serum alkaline phosphatase , C-reactive protein , and IL-6 , and white blood cells occurred in the 6.4 g/d CLA group , although all values remained within normal limits . The intervention was well tolerated and no severe adverse events were reported , although mild gastrointestinal adverse events were reported in all treatment groups . In conclusion , whereas CLA may increase lean body mass in obese humans , it may also increase markers of inflammation in the short term BACKGROUND Short-term trials showed that conjugated linoleic acid ( CLA ) may reduce body fat mass ( BFM ) and increase lean body mass ( LBM ) , but the long-term effect of CLA was not examined . OBJECTIVE The objective of the study was to ascertain the 1-y effect of CLA on body composition and safety in healthy overweight adults consuming an ad libitum diet . DESIGN Male and female volunteers ( n = 180 ) with body mass indexes ( in kg/m(2 ) ) of 25 - 30 were included in a double-blind , placebo-controlled study . Subjects were r and omly assigned to 3 groups : CLA-free fatty acid ( FFA ) , CLA-triacylglycerol , or placebo ( olive oil ) .  Change in BFM , as measured by dual-energy X-ray absorptiometry , was the primary outcome . Secondary outcomes included the effects of CLA on LBM , adverse events , and safety variables . RESULTS Mean ( + /- SD ) BFM in the CLA-triacylglycerol and CLA-FFA groups was 8.7 + /- 9.1 % and 6.9 + /- 9.1 % , respectively , lower than that in the placebo group ( P < 0.001 ) . Subjects receiving CLA-FFA had 1.8 + /- 4.3 % greater LBM than did subjects receiving placebo ( P = 0.002 ) . These changes were not associated with diet or exercise . LDL increased in the CLA-FFA group ( P = 0.008 ) , HDL decreased in the CLA-triacylglycerol group ( P = 0.003 ) , and lipoprotein(a ) increased in both CLA groups ( P < 0.001 ) compared with month 0 . Fasting blood glucose concentrations remained unchanged in all 3 groups . Glycated hemoglobin rose in all groups from month 0 concentrations , but there was no significant difference between groups . Adverse events did not differ significantly between groups . CONCLUSION Long-term supplementation with CLA-FFA or CLA-triacylglycerol reduces BFM in healthy overweight adults BACKGROUND Animal studies suggest that dietary cis-9,trans-11 ( c9,t11 ) conjugated linoleic acid ( CLA ) may inhibit or regress the development of atherosclerosis . The effect of CLA on atherosclerosis has not been assessed in humans . OBJECTIVE We investigated the effect of c9,t11 CLA supplementation on aortic pulse wave velocity ( a marker of atherosclerosis ) and on cardiovascular risk factors in overweight and obese but otherwise apparently healthy subjects . DESIGN In a double-blind , r and omized , placebo-controlled , parallel-group trial , we r and omly assigned 401 subjects , aged 40 - 70 y and with a body mass index ( in kg/m(2 ) ) > or = 25 , to receive either 4 g CLA/d ( 2.5 g c9,t11 CLA/d and 0.6 g trans-10,cis-12 CLA/d ) or placebo supplements for 6 mo . Aortic pulse wave velocity , blood pressure , anthropometric characteristics , and concentrations of fasting lipid , glucose , insulin , and C-reactive protein were measured before and after supplementation . RESULTS During the intervention , mean ( + /-SE ) pulse wave velocity did not change in the c9,t11 CLA group ( Delta0.00 + /- 0.07 ) compared with the placebo group ( Delta0.09 + /- 0.06 ) . There was no effect of c9,t11 CLA supplementation on blood pressure , body composition , insulin resistance , or concentrations of lipid , glucose , and C-reactive protein . CONCLUSION This study does not support an antiatherosclerotic effect or an effect on cardiovascular risk factors of c9,t11 CLA . This trial was registered at www . clinical trials.gov as NCT00706745 INTRODUCTION Conjugated linoleic acids ( CLAs ) have shown beneficial effects in weight control therapy however this relation is not clear . OBJETIVE The aim of the study was to examine the effects and safety of 3 g of a 1:1 mix of c9-t11 and t10-c12 on weight control and body composition in healthy overweight individuals . METHODS A prospect i ve , placebo-controlled , r and omised double-blind , parallel clinical trial lasting 24 weeks was carried out in 38 volunteers ( 29w , 9 m ) aged 30 - 55 years and BMI ≥27-<30 kg/m2 who consumed 200 ml/day of skimmed milk with 3 g of CLAs or 3 g olive oil ( placebo ) .  Anthropometric , biochemical and dual x-ray absorptiometry ( DXA ) tests were measured . Diet and physical activity were assessed . RESULTS Subjects maintained their habitual dietary and exercise patterns over the study . Only CLA group showed a significant decrease in weight ( 74.43 ± 10.45 vs 73.54 ± 11.66 kg , p = 0.029 ) and waist circumference ( 91.45 ± 10.33 vs 90.65 ± 9.84 cm , p = 0.012 ) between baseline and end of the study . BMI and waist height ratio decreased ( 28.44 ± 1.08 vs 27.81 ± 1.43 kg/m2 , p = 0.030 and 0.57 ± 0.05 vs 0.56 ± 0.04 p = 0.013 respectively ) in CLA group at the end . CLA group experienced a reduction in total fat mass after 24 weeks ( 38.62 ± 5.02 vs 36.65 ± 5.64 % , p = 0.035 ) . No decrease was observed in Control group . HOMA index had no changes . CONCLUSIONS The consumption of skimmed milk enriched with 3 g of a 1:1 mixture of c9-t11 and t10-c12 for 24 weeks led to a decrease in body weight and total fat mass in healthy , overweight subjects who maintained habitual diets and exercise patterns . No adverse effects were observed . Registered under Clinical Trials.gov Identifier No. NCT01503047 Consumption of industrial trans fatty acids ( iTFA ) increases LDL cholesterol , decreases HDL cholesterol , and is strongly associated with a higher risk of cardiovascular disease ( CVD ) . However , changes in circulating cholesterol can not explain the entire effect . Therefore , we studied whether iTFA and conjugated linoleic acid ( CLA ) affect markers of inflammation and oxidative stress .  Sixty-one healthy adults consumed each of 3 diets for 3 wk , in r and om order . Diets were identical except for 7 % of energy provided by oleic acid ( control diet ) , iTFA , or CLA . At the end of the 3 wk , we measured plasma inflammatory markers IL-6 , C-reactive protein , tumor necrosis factor receptors I and II ( TNF-RI and -RII ) , monocyte chemotactic protein-1 and E-selectin , and urinary 8-iso-PGF(2α ) , a marker of lipid peroxidation . Consumption of iTFA caused 4 % lower TNF-RI concentrations and 6 % higher E-selectin concentrations compared with oleic acid ( control ) and had no significant effect on other inflammatory markers . CLA did not significantly affect inflammatory markers . The urine concentration of 8-iso-PGF(2α ) [ geometric mean ( 95 % CI ) ] was greater after the iTFA [ 0.54 ( 0.48 , 0.60 ) nmol/mmol creatinine ] and the CLA [ 1.2 ( 1.1 , 1.3 ) nmol/mmol creatinine ] diet periods than after the control period [ 0.45 ( 0.41 , 0.50 ) nmol/mmol creatinine ; P < 0.05 ] . In conclusion , high intakes of iTFA and CLA did not substantially affect plasma concentrations of inflammatory markers , but they increased the urine 8-iso-PGF(2α ) concentration . However , it is unlikely this plays a major role in the mechanism by which iTFA increase the risk of CVD . However , more research is needed to fully underst and the implication s of these findings BACKGROUND Results of a pilot study suggested that cis-9 , trans-11 conjugated linoleic acid ( CLA ) improved LDL phenotype in moderately overweight subjects with LDL phenotype B. OBJECTIVE Initiated by the results of this pilot study , we have specifically design ed a study to test the hypothesis that cis-9 , trans-11 conjugated linoleic acid improves LDL phenotype in moderately overweight subjects with LDL phenotype B. Effects on the serum lipid profile , on plasma glucose and insulin concentrations , and on clinical parameters were also examined . DESIGN Volunteers with LDL phenotype B were divided into three groups consuming daily a drinkable dairy product not enriched with CLA ( placebo , n = 34 ) , the same dairy product enriched with 3 g c9 , t11 CLA ( n = 34 ) , or the dairy product enriched with 3 g t10 , c12 CLA ( n = 19 ) for 13 weeks . RESULTS Median changes in the proportions of plasma small dense LDL were -2.0 % in the control group and -0.1 % in the c9 , t11 CLA and t10 , c12 CLA groups ( p = 0.981 for the differences between the groups ) . c9 , t11 CLA or t10 , c12 CLA did also not affect serum concentrations of LDL and HDL cholesterol , and of triacylglycerol , and plasma concentrations of glucose and insulin . CONCLUSIONS In humans with LDL phenotype B , c9 , t11 CLA and t10 , c12 CLA do not beneficially change risk factors for cardiovascular disease or diabetes Objectives —To determine the effect of dietary supplementation with conjugated linoleic acid ( CLA ) on body mass index ( BMI ) , body fat distribution , endothelial function , and markers of cardiovascular risk . Methods and Results —Forty healthy volunteers with BMI > 27 kg/m2 were r and omized to receive a CLA isomeric mixture or olive oil in a 12-week double-blind study . Subcutaneous body fat and abdominal/hepatic fat content were assessed using skin-fold thicknesses and computed tomography scanning , respectively . Endothelial function was assessed by brachial artery flow-mediated dilatation ( FMD ) . Plasma isoprostanes were measured as an index of oxidative stress . CLA supplementation did not result in a significant change in BMI index or total body fat . There was a significant decrease in limb ( −7.8 mm , P<0.001 ) , but not torso skin-fold thicknesses or abdominal or liver fat content . Brachial artery FMD declined ( −1.3 % , P=0.013 ) , and plasma F2-isoprostanes increased ( + 91pg/mL , P=0.042 ) . Conclusions —A CLA isomeric mixture had at most modest effects on adiposity and worsened endothelial function . On the basis of these results , the use of the isomeric mixture of CLA as an aid to weight loss can not be recommended Aging is associated with lower muscle mass and an increase in body fat . We examined whether creatine monohydrate ( CrM ) and conjugated linoleic acid ( CLA ) could enhance strength gains and improve body composition ( i.e. , increase fat-free mass ( FFM ) ; decrease body fat ) following  resistance exercise training in older adults ( > 65 y ) . Men ( N = 19 ) and women ( N = 20 ) completed six months of resistance exercise training with CrM (5g/d)+CLA ( 6g/d ) or placebo with r and omized , double blind , allocation . Outcomes included : strength and muscular endurance , functional tasks , body composition ( DEXA scan ) , blood tests ( lipids , liver function , CK , glucose , systemic inflammation markers ( IL-6 , C-reactive protein ) ) , urinary markers of compliance ( creatine/creatinine ) , oxidative stress ( 8-OH-2dG , 8-isoP ) and bone resorption ( Ν-telopeptides ) . Exercise training improved all measurements of functional capacity ( P<0.05 ) and strength ( P<0.001 ) , with greater improvement for the CrM+CLA group in most measurements of muscular endurance , isokinetic knee extension strength , FFM , and lower fat mass ( P<0.05 ) . Plasma creatinine ( P<0.05 ) , but not creatinine clearance , increased for CrM+CLA , with no changes in serum CK activity or liver function tests . Together , this data confirms that supervised resistance exercise training is safe and effective for increasing strength in older adults and that a combination of CrM and CLA can enhance some of the beneficial effects of training over a six-month period . Trial Registration . Clinical Trials.gov Long-term supplementation with conjugated linoleic acid ( CLA ) reduces body fat mass ( BFM ) and increases or maintains lean body mass ( LBM ) . However , the regional effect of CLA was not studied . The study aim ed to evaluate the effect of CLA per region and safety in healthy , overweight and obese adults . A total of 118 subjects ( BMI : 28 - 32 kg/m2 ) were included in a double blind , placebo-controlled trial . Subjects were r and omised into two groups supplemented with either 3 x 4 g/d CLA or placebo for 6 months . CLA significantly decreased BFM at month 3 ( Delta=- 0 x 9 % , P=0 x 016 ) and at month 6 ( Delta=- 3 x 4 % , P=0 x 043 ) compared with placebo . The reduction in fat mass was located mostly in the legs ( Delta=- 0 x 8 kg , P<0 x 001 ) , and in women ( Delta=-1 x 3 kg , P=0 x 046 ) with BMI > 30 kg/m2 ( Delta=-1 x 9 kg , P=0 x 011 ) , compared with placebo . The waist-hip ratio decreased significantly ( P=0 x 043 ) compared with placebo .  LBM increased ( Delta=+0 x 5 kg , P=0 x 049 ) within the CLA group . Bone mineral content was not affected ( P=0 x 70 ) . All changes were independent of diet and physical exercise . Safety parameters including blood lipids , inflammatory and diabetogenic markers remained within the normal range . Adverse events did not differ between the groups . It is concluded that supplementation with CLA in healthy , overweight and obese adults decreases BFM in specific regions and is well tolerated Background / Objectives : Dietary addition of either conjugated linoleic acid ( CLA ) or n-3 long-chain polyunsaturated fatty acids ( n-3 LC-PUFAs ) has been shown to alter adiposity and circulating lipids , risk markers of cardiovascular diseases . However , CLA may decrease insulin sensitivity , an effect that may be reversed by n-3 LC-PUFA . Thus , the potential of CLA plus n-3 LC-PUFA to affect insulin secretion and sensitivity in non-diabetic young and old , lean and obese subjects was tested . Subjects/ Methods : CLA ( 3 g daily ) plus n-3 LC-PUFA ( 3 g daily ) or control oil ( 6 g daily ) was given to lean ( n=12 ; BMI 20–26 kg/m2 ) or obese ( n=10 ; BMI 29–35 kg/m2 ) young ( 20–37 years old ) or lean ( n=16 ) or obese ( n=11 ) older men ( 50–65 years ) for 12 weeks . The study had a double-blind , placebo-controlled r and omized crossover design , and primary end points were insulin secretion and sensitivity during a st and ardized meal test , evaluated by modeling glucose , insulin and C-peptide data . Results : The combination was well tolerated . There was no significant difference in fasting levels of glucose , insulin or C-peptide after CLA/n-3 LC-PUFA treatment compared with control oil . Neither insulin secretion nor estimated sensitivity was affected by CLA/n-3 LC-PUFA in lean or obese young subjects or in older lean subjects . However , in older obese subjects , estimated insulin sensitivity was reduced with CLA/n-3 LC-PUFA compared with control ( P=0.024 ) . Conclusions : The results do not support beneficial effects of CLA/n-3 LC-PUFA for β-cell dysfunction or insulin resistance in humans but suggest that insulin sensitivity in older obese subjects is reduced Objective : The incidence of obesity and overweight in the US has increased considerably during the past two decades and currently affects 65 % of the adult population . Research has indicated that small , yet irreversible , gains during the holiday season contribute to increases in weight during adulthood . Conjugated linoleic acid ( CLA ) , a naturally occurring dietary fatty acid , has been found to reduce weight gain and dramatically decrease fat mass in animals . Although research in humans has shown inconsistent results , most studies have been of insufficient duration or have utilized body composition methods that are less accurate than the currently accepted criterion . Design : R and omized , double-blind , placebo-controlled study of 3.2 g/day CLA for 6 months . Subjects : Forty healthy , overweight subjects ( age : 18–44 years ; body mass index : 25–30 kg/m2 ) Measurements : Body composition by the four-compartment model , resting metabolic rate ( RMR ) by indirect calorimetry , self-reported physical activity and dietary intake , and blood chemistries were determined at baseline and after 6 months . Body weight was measured monthly during the pre-holiday season ( August – October ) , holiday season ( November – December ) and post-holiday season ( January – March ) . Adverse events were assessed monthly . Results : Compared to CLA , the placebo group showed a greater rate of weight gain during the holiday season ( P=0.01 ) . Within the placebo group , holiday weight change was significantly greater compared to the pre-holiday period ( August – October ) ( P=0.03 ) . Six-month change in body composition was improved with CLA compared to placebo ( P=0.02 ) , and body fat was significantly reduced within the CLA group ( −1.0±2.2 kg , P=0.05 ) . CLA had no effect on RMR , physical activity or dietary intake . The rate of reported negative emotions decreased significantly with CLA , although there was no difference in any other category of adverse event . In comparison to the placebo , CLA did not affect insulin resistance , blood lipids and markers of liver function or markers of inflammation , with the exception of a significant decrease in a biomarker of endothelial dysfunction . Conclusion : CLA  supplementation among overweight adults significantly reduced body fat over 6 months and prevented weight gain during the holiday season . Although no adverse effects were seen , additional studies should evaluate the effect of prolonged use of CLA Conjugated linoleic acid ( CLA ) may decrease adiposity and improve blood lipid profiles under some conditions . The goal of this study was to determine the effects of CLA supplementation on blood lipid profiles and adiposity of rats fed a diet containing a primarily saturated fat versus a diet containing a primarily unsaturated fat . Twenty-eight male Sprague-Dawley rats were r and omly assigned to one of four diets containing coconut oil , coconut oil with CLA , corn oil or corn oil with CLA . After 28 days , blood was collected and serum concentrations of total cholesterol ( TC ) , HDL-cholesterol ( HDL-C ) , and triacylglycerols ( TG ) were assessed . Food intake , body weights , and epididymal fat pads were measured . No significant differences ( p>0.05 ) were noted among groups for amount of food consumed , weight gained , food efficiency ratio or serum TG concentrations . TC concentrations were lower ( p<0.05 ) in the CLA-supplemented rats that were fed coconut oil but not those consuming corn oil . Serum HDL-C was lower ( p<0.05 ) in rats consuming corn oil but was not significantly different ( p>0.05 ) for CLA supplemented groups . Epididymal fat pads weighed significantly more ( p<0.05 ) in the coconut oil fed group compared to the corn oil fed group , but there was no significant difference ( p>0.05 ) between the corn oil and coconut oil + CLA group . Overall , this study suggests that CLA is more beneficial for control of blood lipids and adiposity when supplemented to a diet rich in saturated versus unsaturated fat Isomers of conjugated linoleic acids ( CLA ) reduce fat mass ( FM ) and increase insulin sensitivity in some , but not all , murine studies . In humans , this effect is still debatable . In this study , we compared the effect of 2 CLA supplements on total and regional FM assessed by dual energy X-ray absorptiometry , changes in serum insulin and glucose concentrations , and adipose tissue ( AT ) gene expression in humans . In a double-blind , parallel , 16-wk intervention , we r and omized 81 healthy postmenopausal women to 1 ) 5.5 g/d of 40/40 % of cis9,trans11-CLA ( c9,t11-CLA ) and trans10,cis12-CLA ( t10,c12-CLA ) ( CLA-mix ) ; 2 ) cis9 , trans11-CLA ( c9,t11-CLA ) ; or 3 ) control ( olive oil ) .  We assessed all variables before and after the intervention . The CLA-mix group had less total FM ( 4 % ) and lower-body FM ( 7 % ) than the control ( P = 0.02 and < 0.001 , respectively ) . Post hoc analyses showed that serum insulin concentrations were greater in the CLA-mix group ( 34 % ) than the control group ( P = 0.02 ) in the highest waist circumference tertile only . AT mRNA expression of glucose transporter 4 , leptin , and lipoprotein lipase was lower , whereas expression of tumor necrosis factor-alpha was higher in the CLA-mix group than in the control group ( P < 0.04 ) . In conclusion , a 50:50 mixture of c9,t11- and t10,c12-CLA isomers result ed in less total and lower-body FM  in postmenopausal women and greater serum insulin concentrations in the highest waist circumference tertile . Future research is needed to confirm the insulin desensitizing effect of the CLA mixture and the effect on the mRNA expression of adipocyte-specific genes in humans Although patients with type 2 diabetes have a high risk of death from cardiovascular disease ( CVD ) , the traditional risk factors do not fully explain this excess of mortality . In this regard , it would be of great interest to assess the role of nontraditional risk factors such as lipoprotein(a ) in cardiovascular mortality in diabetic patients . Danesh et al. ( 1 ) , in a meta- analysis including the prospect i ve studies published before 2000 , concluded that there was a clear association between lipoprotein(a ) and CVD in the general population . Further prospect i ve reports have demonstrated that lipoprotein(a ) is an independent predictor of the development of CVD ( 2–5 ) . However , little data exist on the clinical importance of lipoprotein(a ) in the diabetic population . We herein report a prospect i ve study to evaluate the relationship between lipoprotein(a ) levels and cardiovascular mortality in type 2 diabetic patients of Caucasian origin . One hundred twenty-two consecutive type 2 diabetic out patients of Caucasian origin attending the outpatient diabetic unit of a university hospital between April and May of 1993 were enrolled for a 10-year prospect i ve study . To avoid the possible transient increase of lipoprotein(a ) after starting insulin treatment ( 6 ) , all patients in whom insulin treatment was initiated in the months before the study were excluded . Patients with renal failure were also excluded . To assess evidence of macroangiopathy , we used the World Health Organization ( WHO ) protocol , which includes a detailed question naire and a 12-lead electrocardiogram ( 7,8 ) . By the end of the study , data were available from 100 patients . Of these , 29 had died ( 23 from CVD ) . Metabolic parameters Objective : Conjugated linoleic acid ( CLA ) showed a wide range of beneficial biological effects with relevance for cardiovascular health in animal models and humans . Most human studies used olive oil as a reference . This study assessed the effect of CLA as compared with safflower oil on endothelial function and markers of cardiovascular risk in overweight and obese men .  Heated safflower oil and olive oil were given for additional descriptive control . Methods : Eighty-five overweight men ( aged 45–68 years , body mass index 25–35 kg/m2 ) were r and omized to receive 4.5 g/d of the CLA isomeric mixture , safflower oil , heated safflower oil , or olive oil in a 4-week double-blind study .  Endothelial function was assessed by peripheral arterial tonometry ( PAT ) index determination in the fasting and postpr and ial state ( i.e. , 4 hours after consumption of a fat- and sucrose-rich meal ) . Results : CLA as compared with safflower oil consumption did not impair fasting or postpr and ial PAT index but decreased body weight .  CLA as compared with safflower oil did not change total , low-density lipoprotein ( LDL ) , or high-density lipoprotein ( HDL ) cholesterol ; triglycerides ; insulin sensitivity indices ; C-reactive protein ; soluble adhesion molecules ; oxidized LDL ; lipoprotein a ( Lp[a ] ) ; paraoxonase ; or platelet-activating factor acetylhydrolase ( PAF-AH ) activity , but significantly reduced arylesterase activity and increased concentrations of the F2-isoprostane 8-iso-prostagl and in F (PGF)2α . Conclusion : CLA did not impair endothelial function . Other parameters associated with metabolic syndrome and oxidative stress were not changed or were slightly improved . Results suggest that CLA does not increase cardiovascular risk . Increased F2-isoprostane concentrations in this context may not indicate increased oxidative stress Conjugated linoleic acid ( CLA ) is shown to have chemoprotective properties in various experimental cancer models . CLA is easily oxidised and it has been suggested that an increased lipid oxidation may contribute to the antitumorigenic effects . This report investigates the urinary levels of 8‐iso‐PGF2α , a major isoprostane and 15‐keto‐dihydro‐PGF2α , a major metabolite of PGF2α , as indicators of non‐enzymatic and enzymatic lipid peroxidation after dietary supplementation of CLA in healthy human subjects for 3 months . A significant increase of both 8‐iso‐PGF2α and 15‐keto‐dihydro‐PGF2α in urine was observed after 3 months of daily CLA intake ( 4.2 g/day ) as compared to the control group ( P<0.0001 ) . Conjugated linoleic acid had no effect on the serum α‐tocopherol levels . However , γ‐tocopherol levels in the serum increased significantly ( P=0.015 ) in the CLA‐treated group . Thus , CLA may induce both non‐enzymatic and enzymatic lipid peroxidation in vivo . Further studies of the mechanism behind , and the possible consequences of , the increased lipid peroxidation after CLA supplementation are urgently needed
target: Conclusion The current systematic review and meta- analysis showed that the long-term consumption of CLA increases the levels of CRP and Lp(a )
background: Background C-reactive protein ( CRP ) and lipoprotein ( a ) ( Lp[a ] ) play essential roles in cardiovascular disease incidence .
  This study aim ed to review the association between the intake of conjugated linoleic acid ( CLA ) in the form of dietary supplement or enriched food with different treatment duration s and the levels of Lp(a ) and CRP in human studies .