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 .
Effects of two conjugated linoleic Acid isomers on body fat mass in overweight humans.
OBJECTIVE To examine the effects of two different conjugated linoleic acid ( CLA ) isomers at two different intakes on body composition in overweight humans . RESEARCH METHODS AND PROCEDURES Eighty-one middle-aged , overweight , healthy men and women participated in this bicentric , placebo-controlled , double-blind , r and omized study . For 6 weeks ( run-in period ) , all subjects consumed daily a drinkable dairy product containing 3 g of high oleic acid sunflower oil . Volunteers were then r and omized over five groups receiving daily either 3 g of high oleic acid sunflower oil , 1.5 g of cis-9,trans-11 ( c9t11 ) CLA , 3 g of c9t11 CLA , 1.5 g of trans-10,cis-12 ( t10c12 ) CLA , or 3 g of t10c12 CLA administrated as triacylglycerol in a drinkable dairy product for 18 weeks . Percentage body fat mass and fat and lean body mass were assessed at the end of the run-in and experimental periods by DXA . Dietary intake was also recorded . RESULTS Body fat mass changes averaged 0.1 + /- 0.9 kg ( mean + /- SD ) in the placebo group and -0.3 + /- 1.4 , -0.8 + /- 2.1 , 0.0 + /- 2.3 , and -0.9 + /- 1.7 kg in the 1.5-g c9t11 , 3-g c9t11 , 1.5-g t10c12 , and 3-g t10c12 groups , respectively . Changes among the groups were not significantly different ( p = 0.444 ) . Also , lean body mass and dietary intake were not significantly different among the treatments . DISCUSSION A daily consumption of a drinkable dairy product containing up to 3 g of CLA isomers for 18 weeks had no statistically significant effect on body composition in overweight , middle-aged men and women
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 .