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 randomly 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.