the effect of conjugated linoleic acids, vitamin e and their com¬bination on lipid peroxidation in active rheumatoid arthritis

background: reactive oxygen species (ros) have important role in the etiology and pathogenesis of rheumatoid arthritis (ra). we investigated the effect of conjugated linoleic acids (clas) and vitamin e on lipid peroxidation. methods: in a randomized, double-blind placebo, controlled, clinical trial 87 patients with active ra were enrolled. they were divided into 4 groups, received one of the following daily supplement for 3 months; 1- group c: 2.5gr cla, that con­tained 2 gr 50:50 mix of cis 9- trans 11 and trans 10-cis 12 clas, 2- group e: 400mg vitamin e, 3- group ce: clas  plus vita­min e, 4- group p: placebo. after supplementation glutathione peroxidase (gsh-px) level increased in c, e and ce groups, ce group had  lower gsh-px than p group( p≤ 0 . 05). results: glutathione reductase (gr) increased in ce, c and p groups. catalase increased in all groups, but enhancement was significant in c and ce. superoxide dismutase (sod) decreased in e and c ( p≤ 0 . 05). catalase and sod did not show signifi­cant differences between groups. malondialdehyde (mda) decreased significantly in all groups but this decrease was only significant in ce in comparison with other groups. conclusion:  clas might be useful in reducing oxidative stress in ra