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 .
Conjugated linoleic acid supplementation for twelve weeks increases lean body mass in obese humans.
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
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 .