Effects of conjugated linoleic acid supplementation on inflammatory mediators and immunoglobulins in overweight Korean females

Abstract

Conjugated linoleic acids (CLAs) are a group of fatty acids shown to have anti‐adipogenic and anti‐inflammatory properties, and beneficial effects on immune function. In a double‐blind placebo‐controlled study, 81 overweight premenopausal Korean females (BMI ≥ 23 kg/m2) aged 20‐50 years were randomized to one of 4 groups. Each group was received placebo (olive oil), a CLA mixture 1.5g/d, 2.25g/d or 3g/d for 12 weeks. The major isomer content of tested CLA mixture (78.4% free fatty acids) was 36.8% cis‐9 trans‐11 CLA and 37.3% trans‐10 cis‐12 CLA. With 12 weeks of supplementation, mean C‐reactive protein was increased by 35% in a group with olive oil, while groups with CLA at 2.25 and 3mg/d showed 1 and 11% elevation, respectively (p>0.05). Plasma interleukin‐10 (IL‐10), an anti‐inflammatory cytokine, was significantly increased with 3g/d CLA supplementation for 12 weeks (P<0.05). Although mean plasma IL‐10 was found to be increased after 12 weeks in all groups, the groups with CLA supplementation showed greater changes (187‐232%) compared with placebo (146%). Elevated plasma immunoglobulin M was observed in 73% of individuals who received 3mg/d CLA for 12 weeks. These results suggest that CLA supplementation might have a potential to modulate markers related with inflammation and immune function. However, the effects observed in the current trial seem to be much more subtle than those found in animals and few other clinical studies, and a clinically useful level of CLA dose should be further elucidated.