The Effect of Conjugated Linoleic Acid Supplementation on Lipid-Related Cardiovascular Biomarkers in Obese Adults

Background: Studies have shown incompatible findings regarding the effects of conjugated linoleic acid (CLA) supplementation on cardiovascular diseases (CVDs) risk factors. The aim of this study was to evaluate the effect of daily CLA supplementation on serum insulin and lipid- related CV biomarkers in obese adults. Methods: This randomized double-blind clinical trial was conducted on 54 adults categorized as class I obesity. The participants were randomly assigned into two groups (n=27) receiving a total of 3,000 mg/d of a 50:50 mixture of CLA isomers for three months in intervention group (IG) and 500 mg/d paraffin in placebo group (PG). Moreover, fasting serum levels of insulin, lipid profile, non-HDL-Cholesterol (non-HDL-C), atherogenic index of plasma (AIP), total triglyceride (TG)/HDL-C, and cholesterol/HDL-C ratio were measured.  The main statistical analysis method was independent t-test for changes. Results: Changes between the groups showed a significant decrease in total cholesterol (P=0.03), LDL-C (P=0.04), and non-HDL-C (P=0.03), and also a significant increase in AIP (P=0.04) in IG compared to the PG. A remarkable decrease was found in HDL-C and cholesterol/HDL-C ratio. In addition, a remarkable increase was observed in TG in this context. Serum insulin, VLDL-C, and LDL-C/HDL-C ratio showed no significant changes during the intervention period. The use of CLA supplementation could help reduce some adverse fractions of serum lipid profile, particularly TC, non-HDL-C and LDL-C. Conclusions: Regarding the augmenting effects of CLA intake on AIP as a strong predictive marker for CVDs, it is difficult to confirm the beneficial effects of CLA supplementation in preventing CVDs.