The effect of n-3 long chain fatty acids supplementation on plasma peroxisome proliferator activated receptor gamma and thyroid hormones in obesity

BACKGROUND Peroxisome proliferator-activated receptor gamma (PPAR γ) is a transcription factor, which is abundantly expressed in adipose tissue and has a direct link to adiposity. It seems that long-chain polyunsaturated fatty acids (LC-PUFAs) can regulate PPAR γ expression. The purpose of this study was to investigate the effects of n-3LC PUFA supplementation on plasma levels of PPAR γ and thyroid hormones in obesity. MATERIALS AND METHODS In a randomized double-blind controlled trial, 66 subjects with obesity were assigned to 2 groups. Participants in intervention group consumed omega3 capsules contained 1000 mg n-3 fatty acids (180 mg of eicosapentaenoic acid [EPA] and 120 mg of docosahexaenoic acid [DHA]) and placebo group consumed placebo capsules contained paraffin twice a day for 4 wk. Fasting blood samples and weight measurements were collected at the baseline and at the end of the trial. Plasma PPAR γ and thyroid hormones were measured by ELISA. Data were analyzed using a repeated measure model-two factor for comparing two groups in two times. RESULTS No significant changes were observed in PPAR γ levels between and within the groups after supplementation (P>0.05). N-3LC PUFA supplementation significantly increased T4 levels after 4 wk (P<0.05) but T3 and TSH did not change significantly. CONCLUSION Our study showed that n-3LC PUFAs supplementation increased T4 levels. However, no significant changes in T3, TSH and PPAR γ plasma levels were observed in obese adults.