The effect of supplementation with omega-3 polyunsaturated fatty acids on markers of oxidative stress in elderly exposed to PM2.5

Abstract

Background: The mechanisms of particulate matter (PM)-induced health effects are believed to involve inflammation and oxidative stress. Increased intake of omega-3 polyunsaturated fatty acids (n-3 PUFA) appears to have anti-inflammatory effects. Objective: As part of a trial to evaluate whether n-3 PUFA supplementation could protect against the cardiac alterations linked to PM exposure, we measured biomarkers of response to oxidative stimuli (copper/zinc (Cu/Zn) superoxide dismutase (SOD) activity, lipoperoxidation (LPO) products, and reduced glutathione (GSH)] and evaluated the impact of supplementation on plasma levels. Methods: We recruited residents from a nursing home in Mexico City chronically exposed to PM ≤ 2.5 μm in aerodynamic diameter (PM2.5) and followed them from 26 September 2001 to 10 April 2002. We randomly assigned subjects in a double-blind fashion to receive either fish oil (n-3 PUFA) or soy oil. We measured PM2.5 levels indoors at the nursing home, and measured Cu/Zn SOD ativity, LPO products, and GSH at different times during presupplemtation and supplementation phases. Results: Supplementation with either fish or soy oil was related to an increase of Cu/Zn SOD activity and an increase in GSH plasma levels, whereas exposure to indoor PM2.5 levels was related to a decrease in Cu/Zn SOD activity and GSH plasma levels. Conclusion: Supplementation with n-3 PUFA appeared to modulate the adverse effects pf PM2.5 on these biomarkers, particularly in the fish oil group. Supplementation with n-3 PUFA could modulate oxidative responce to PM2.5 exposure.