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 .
Effect of Conjugated Linoleic Acid, Vitamin E, Alone or Combined on Immunity and Inflammatory Parameters in Adults with Active Rheumatoid Arthritis: A Randomized Controlled Trial
Background : Little information about the effects of conjugated linoleic acids ( CLAs ) on inflammation and immune function in humans is available . This study investigated the effects of CLAs , with and without Vitamin E on immunity and inflammatory parameters in adults with active rheumatoid arthritis ( RA ) . Methods : In a double-blind clinical trial , 78 patients were r and omly divided into four groups , each group receiving one of the following daily supplement for 3 months ; group C : 2.5 g CLAs , group E : 400 mg Vitamin E , group CE : CLAs plus Vitamin E , group P : Placebo .  Cytokines , matrix metalloproteinase 3 ( MMP-3 ) and citrullinated antibody ( CCP-A ) were measured by ELISA method and Vitamin E by high-performance liquid chromatography . Results : Consider statistical methods there were no significant differences between groups in cytokines interleukin-2 ( IL-2 ) , IL-4 , tumor necrosis factor-α ( TNF-α ) , IL-1β , IL-2/IL-4 , CCP-A white blood cells and neutrophils , lymphocyte , monocytes , and eosinophils numbers . TNF-α decreased in all groups , but its reduction was significant in group CE . IL-1β increased in groups P ( P = 0.004 ) and E ( P = 0.041 ) but the difference between group P and CE was significant . IL-4 decreased in groups C , CE and E ( P = 0.03 , P = 0.03 , P = 0.07 respectively ) . IL2 did not change significantly within groups . CCP-A increased in groups P ( P = 0.035 ) and E ( P = 0.05 ) , while it decreased in groups CE ( P = 0.034 ) . CCP-A and MMP-3 decrease were significant between groups P and CE . MMP-3 reduction was significant in group CE . Conclusions : Co-supplementation CLAs and Vitamin E may be effective in the level of inflammatory markers in RA patients
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 .