Conjugated linoleic acid improves airway hyper‐reactivity in overweight mild asthmatics Effect of conjugated linoleic acid and omega-3 fatty acid supplementation on inflammatory and oxidative stress markers in atherosclerotic patients The effects of conjugated linoleic acid supplementation on immune function in healthy volunteers 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. Conjugated linoleic acid induces lipid peroxidation in humans Conjugated linoleic acid supplementation for twelve weeks increases lean body mass in obese humans. Conjugated linoleic acid supplementation for 8 weeks does not affect body composition, lipid profile, or safety biomarkers in overweight, hyperlipidemic men. Conjugated linoleic acid reduces body fat mass in overweight and obese humans. The role of conjugated linoleic acid in reducing body fat and preventing holiday weight gain Conjugated linoleic acid supplementation reduces peripheral blood mononuclear cell interleukin-2 production in healthy middle-aged males. Conjugated linoleic acid supplementation for 1 y reduces body fat mass in healthy overweight humans. Supplementation with conjugated linoleic acid for 24 months is well tolerated by and reduces body fat mass in healthy, overweight humans. A diet rich in conjugated linoleic acid and butter increases lipid peroxidation but does not affect atherosclerotic, inflammatory, or diabetic risk markers in healthy young men. Effects of conjugated linoleic acid supplementation on blood lipids and adiposity of rats fed diets rich in saturated versus unsaturated fat. Effects of Conjugated Linoleic Acid Supplementation During Resistance Training on Body Composition, Bone Density, Strength, and Selected Hematological Markers Effect of conjugated linoleic acid supplementation on weight loss and body fat composition in a Chinese population. Anti-inflammatory effects of conjugated linoleic acid on young athletic males.
Background Conjugated linoleic acids ( CLA ) are naturally occurring fatty acids that have multiple biological properties including the regulation of metabolic , proliferative and immune processes BACKGROUND Cardiovascular disease is the major cause of morbidity , mortality , and disability in Iranian people . Inflammation and oxidative processes are key components of cardiovascular disease . The aim of this study was to evaluate the effect of conjugated linoleic acids ( CLA ) and omega-3 fatty acid ( ω-3 fatty acids ) supplementation on inflammation markers and oxidative stress in atherosclerotic patients . METHODS This study was a two-month clinical , r and omized trial . 90 volunteers who referred to Emam Reza Heart Clinic of Shiraz University of Medical Sciences ( Shiraz , Iran ) from February to March 2011 and had the inclusion criteria of this study were selected . Participants were classified into 3 groups receiving 3 g/d CLA , 1920 mg/d ω-3 , or placebo for 2 months . C-reactive protein ( CRP ) , interleukin-6 ( IL-6 ) , malondialdehyde ( MDA ) , and glutathione peroxidase ( GPx ) were measured before and after supplementation . RESULTS The hs-CRP level decreased significantly in both the omega-3 and CLA group ( P < 0.05 ) . IL-6 reduced significantly in the ω-3 group , but the reduction of IL-6 levels in the CLA group was not significant . GPx increased in the CLA and omega-3 groups ( P < 0.05 ) . MDA level decreased significantly in both omega-3 and CLA groups ( P < 0.05 ) . Comparison between the groups indicates a significant change in CRP levels in the ω-3 group relative to the control group . However , other indices did not cause any significant change in the ω-3 and CLA groups in comparison to the control group . CONCLUSION Diet supplementation with CLA and ω-3 can have a beneficial effect on some indices of inflammatory and oxidative stress Objective : To assess the effects of dietary supplementation using two isomeric blends of conjugated linoleic acid ( CLA ) on immune  function in healthy human volunteers . Design : Double-blind , r and omised , placebo-controlled intervention trial . Subjects and intervention : A total of 55 healthy volunteers ( n=20 males , n=35 females ) were r and omised into one of three study groups who received 3 g/day of a fatty acid blend containing a 50:50 cis-9 , trans-11 : trans-10 , cis-12 CLA isomer blend ( 2 g CLA ) , and 80:20 cis-9 , trans-11 : trans-10 , cis-12 ( 80:20 ) CLA isomer blend ( 1.76 g CLA ) or linoleic acid ( control , 2 g linoleic acid ) for 8 weeks . Results : Supplementation with the 80:20 CLA isomer blend significantly ( P≤0.05 ) enhanced PHA-induced lymphocyte proliferation . CLA  decreased basal interleukin (IL)-2 secretion ( P≤0.01 ) and increased PHA-induced IL-2 and tumor necrosis factor α ( TNFα ) production ( P≤0.01 ) . However , these effects were not solely attributable to CLA as similar results were observed with linoleic acid . CLA supplementation had no significant effect on peripheral blood mononuclear cells IL-4 production , or on serum-soluble intercellular adhesion molecule-1 ( sICAM-1 ) or plasma prostagl and in E2 ( PGE2 ) or leukotreine B4 ( LTB4 ) concentrations . Conclusions : This study shows that CLA supplementation had a minimal effect on the markers of human immune function . Furthermore , supplementation with CLA had no immunological benefit compared with linoleic acid . Sponsorship : CLA supplements were provided by Loders Croklaan 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 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 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 The usefulness of conjugated linoleic acid ( CLA ) as a nutraceutical remains ambiguous . Our objective was , therefore , to investigate the effect of CLA on body composition , blood lipids , and safety biomarkers in overweight , hyperlipidemic men . A double-blinded , 3-phase crossover trial was conducted in overweight ( BMI ≥ 25 kg/m(2 ) ) , borderline hypercholesterolemic [ LDL-cholesterol ( C ) ≥ 2.5 mmol/L ] men aged 18 - 60 y. During three 8-wk phases , each separated by a 4-wk washout period , 27 participants consumed under supervision in r and om order 3.5 g/d of safflower oil ( control ) , a 50:50 mixture of trans 10 , cis 12 and cis 9 , trans 11 ( c9 , t11 ) CLA : Clarinol G-80 , and c9 , t11 isomer : c9 , t11 CLA . At baseline and endpoint of each phase , body weight , body fat mass , and lean body mass were measured by DXA . Blood lipid profiles and safety biomarkers , including insulin sensitivity , blood concentrations of adiponectin , and inflammatory ( high sensitive-C-reactive protein , TNFα , and IL-6 ) and oxidative ( oxidized-LDL ) molecules , were measured . The effect of CLA consumption on fatty acid oxidation was also assessed . Compared with the control treatment , the CLA treatments did not affect changes in body weight , body composition , or blood lipids . In addition , CLA did not affect the β-oxidation rate of fatty acids or induce significant alterations in the safety markers tested . In conclusion , although no detrimental effects were caused by supplementation , these results do not confirm a role for CLA in either body weight or blood lipid regulation in humans 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 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 ) refers to geometric and positional isomers of linoleic acid . Animal studies have shown that CLA modulates the immune system and suggest that it may have a therapeutic role in inflammatory disorders . This double-blind placebo-controlled intervention trial investigated the effects of CLA supplementation on indices of immunity relating to cardiovascular disease ( CVD ) in a cohort of healthy middle-aged male volunteers . Subjects were r and omly assigned to supplement their diet with 2.2 g 50:50 isomeric blend of cis 9 , trans 11 ( c9 , t11)-CLA and trans 10 , cis 12 ( t10 , c12)-CLA or placebo daily for 8 weeks . Interleukin ( IL ) 2 , IL-10 and tumour necrosis factor ( TNF ) alpha were measured in the supernatant of cultured unstimulated and concanavalin A ( Con A)-stimulated peripheral blood mononuclear cells ( P BMC ) by ELISA . Serum IL-6 and plasma CRP were measured by ELISA and plasma fibrinogen by automated clotting assay . Gene expression was investigated by real-time RT-PCR . CLA supplementation significantly reduced Con A-stimulated P BMC IL-2 secretion ( 37.1 % ; P=.02 ) . CLA supplementation had no significant effect on transcription of IL-2 .  CLA supplementation had no direct significant effects on P BMC TNFalpha or IL-10 secretion . Other inflammatory markers associated with CVD , including IL-6 , CRP and fibrinogen , were not affected by CLA supplementation . This study showed that CLA supplementation reduced P BMC IL-2 secretion from Con A-stimulated P BMC but lacked effect on other markers of the human inflammatory response 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 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 Intake of conjugated linoleic acid ( CLA ) has been demonstrated to beneficially affect risk markers of atherosclerosis  and  diabetes in rats . CLA is naturally found in milk fat , especially from cows fed a diet high in oleic acid , and increased CLA intake can occur concomitantly with increased milk fat intake . Our objective was to investigate the effect of CLA as part of a diet rich in butter as a source of milk fat on risk markers of atherosclerosis , inflammation , diabetes type II , and lipid peroxidation .  A total of 38 healthy young men were given a diet with 115 g/d of CLA-rich fat ( 5.5 g/d CLA oil , a mixture of 39.4 % cis9 , trans11 and 38.5 % trans10 , cis12 ) or of control fat with a low content of CLA in a 5-wk double-blind , r and omized , parallel intervention study . We collected blood and urine before and after the intervention . The fatty acid composition of plasma triacylglycerol , cholesterol esters , and phospholipids reflected that of the intervention diets . The CLA diet result ed in increased lipid peroxidation measured as an 83 % higher 8-iso-prostagl and in F2alpha concentration compared with the control , P < 0.0001 . We observed no other significant differences in the effect of the interventions diets . In conclusion , when given as part of a diet rich in butter , a mixture of CLA isomers increased lipid peroxidation but did not affect risk markers of cardiovascular disease , inflammation , or fasting insulin and glucose concentrations 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 Conjugated linoleic acids ( CLA ) are essential fatty acids that have been reported in animal studies to decrease catabolism , promote fat loss , increase bone density , enhance immunity , and serve as an antiatherogenic and anticarcinogenic agent . For this reason , CLA has been marketed as a supplement to promote weight loss and general health . CLA has also been heavily marketed to resistance-trained athletes as a supplement that may help lessen catabolism , decrease body fat , and promote greater gains in strength and muscle mass during training . Although basic research is promising , few studies have examined whether CLA supplementation during training enhances training adaptations and /or affects markers of health . This study evaluated whether CLA supplementation during resistance training affects body composition , strength , and /or general markers of catabolism and immunity . In a double-blind and r and omized manner , 23 experienced , resistance-trained subjects were matched according to body mass and training volume and r and omly assigned to supplement their diet with 9 g·d-1 of an olive oil placebo or 6 g·d-1 of CLA with 3 g·d-1 of fatty acids for 28 days . Prior to and following supplementation , fasting blood sample s , total body mass , and dual-energy X-ray absorptiometry ( DEXA ) determined body composition , and isotonic bench press and leg press 1 repetition maximums ( 1RMs ) were determined . Results revealed that although some statistical trends were observed with moderate to large effect sizes , CLA supplementation did not significantly affect ( p > 0.05 ) changes in total body mass , fat-free mass , fat mass , percent body fat , bone mass , strength , serum substrates , or general markers of catabolism and immunity during training . These findings indicate that CLA does not appear to possess significant ergogenic value for experienced resistance-trained athletes OBJECTIVE Conjugated linoleic acid ( CLA ) has several benefits , including body fat reduction , as proved in animals . However , the results of CLA-induced body composition alterations in humans are inconsistent , and no related data are available for Chinese population s. This study aim ed to determine whether CLA affects body weight ( BW ) loss and body composition of overweight and obese Chinese subjects . METHODS In this r and omized , double-blind , placebo-controlled trial , subjects with a body mass index ( BMI ) of 24 to 35 kg/m(2 ) r and omly received 1.7 g of cis-9,trans-11 and trans-10,cis-12 CLA ( n = 30 ) or placebo ( salad oil ; n = 33 ) in 200 mL of sterilized milk twice daily for 12 wk . Changes in body composition were determined by bioimpedance measurements . RESULTS Sixty-three subjects completed the study  ( CLA , n = 30 ) . After 12 wk , compared with the baseline , the BW , BMI , total fat mass , fat percentage , subcutaneous fat mass , and waist-to-hip ratio decreased in the CLA group ( P < 0.05 ) . The CLA group was stratified by BMI and gender . The BW , BMI , subcutaneous fat mass , and waist-to-hip ratio decreased in 27 subjects with a BMI ≥ 27 , and these indices , except subcutaneous fat mass , were lower in female subjects . The levels of total cholesterol , triacylglycerol , low-density lipoprotein , and plasma fasting glucose increased , whereas those of high-density lipoprotein decreased after 3 mo of CLA treatment . The changes were not significantly different from the baseline values . CONCLUSION The supplementation of CLA for 12 wk in overweight and grade I obese Chinese subjects yielded lower obesity indices , with no obvious adverse effects OBJECTIVE To explore the efficacy of conjugated linoleic acid supplementation on some inflammatory factors in young healthy males during exhaustive exercise . METHODS The r and omised double-blind controlled study was conducted at Ardabil University of Medical Sciences , Iran , from December 2012 to March2013 , and comprised healthy male athletes 18 - 24 years of age . The subjects were r and omly distributed into control and intervention groups . About 5.6 g/day conjugated linoleic acid supplement and oral paraffin ( placebo ) were given to intervention and control groups respectively daily for two weeks . Fasting blood sample s were taken at baseline and at the end of the two weeks of intervention . The subjects underwent exhaustive exercise and then fasting blood sample s were taken . Serum levels of tumour necrosis factor alpha , interleukin-6 , high-sensitivity C-reactive protein , matrix metalloproteinases-2 and 9 were measured . RESULTS There were 23 subjects in the study , with 13(56.5 % ) in the supplemented group and 10(43.4 % ) in the control group .  Serum levels of matrix metalloproteinases-2 and tumour necrosis factor alpha were significantly decreased in the supplemented group ( p<0.05 ) . After exhaustive exercise , serum levels of matrix metalloproteinases-2 , high-sensitivity C-reactive protein and tumour necrosis factor alpha significantly decreased in the supplemented group compared to the control group(p<0.05 ) . CONCLUSIONS Two-week administration of conjugated linoleic acid reduced the inflammatory factors following exhaustive exercise in young healthy males
There was a significant heterogeneity for the impact of CLA  on CRP and IL-6 , but not TNF-α .
Conclusions This meta- analysis showed that CLA supplementation may increase inflammatory markers ( CRP and TNF-α ) .
Background / objectives Conjugated linoleic acid ( CLA ) is a polyunsaturated fatty acid with attractive biological activities .
Numerous studies have been conducted on the inflammation-lowering effects of CLA in in vitro and animal models .
However , the effects of CLA treatment on the inflammatory markers in humans are controversial .