SUPPLEMENTARY SELENIUM INFLUENCES THE RESPONSE TO FATTY ACID-INDUCED OXIDATIVE STRESS IN HUMANS

The mutual influences of wheat selenium (Se) and n-3 polyunsaturated f atty acids (n-3 PUFA) on plasma Se and indicators of increased oxidati ve stress were investigated in a randomized, double-blind study with 3 1 women (23.5 +/- 3.4 yr). Groups 1 and 2 ingested 5.4 g n-3 PUFA dail y (as ethyl esters), whereas groups 3 and 4 received placebo capsules. Groups 2 and 3 received 3 slices of high-Se bread daily, providing 11 5 mu g Se, in addition to the 77 +/- 26 mu g Se in the diet. Groups 1 and 4 received placebo slices. Blood samples were drawn at baseline an d at 3 and 6 wk. Serum Se concentrations increased in both groups give n Se-enriched bread, but significantly less in subjects given n-3 PUFA (group 2). There were no changes in the plasma ratio alpha-tocopherol :mg cholesterol or plasma ascorbic acid levels. In group 1, plasma-con jugated dienes and thiobarbituric acid-reactive substances (TEARS) ros e by 130% (p < 0.005) and 126% (p < 0.005), respectively. Two-way ANOV A showed significant interaction effects of Se and n-3 PUFA on changes in conjugated dienes (p = 0.03) and TBARS (p = 0.015), Se treatment a pparently modifying the peroxidative effects of n-3 PUFA. in subjects receiving n-3 PUFA, changes in conjugated dienes and TEARS were negati vely correlated with changes in serum Se. In summary, n-3 PUFA modifie d the effect of Se supplementation, whereas Se seemed to modify the pe roxidative effects of n-3 PUFA.