Changes in Inflammation Associated with Fish Oil Supplementation

Objective: A characteristic of chronic kidney disease (CKD) is excessive production of pro-inflammatory cytokines.  The benefits of fish oil (FO) for an extensive range of populations and health concerns are apparent, yet the anti-inflammatory benefits for non-dialysis CKD patients are equivocal. Therefore, the purpose of this study was to investigate the effects of daily consumption of FO on IL-1β, IL-6, and TNF-α for 8 weeks in non-dialysis CKD patients.  Design, Setting, and Subjects: The study was conducted using a double blind, randomized, placebo-controlled experimental design.  Thirty-one non-dialysis CKD patients were followed prospectively for 8 weeks while supplementing FO (2.4g/day (1400 mg EPA + 1000 mg DHA) or placebo (safflower oil) in their diet.  Main Outcome Measures: IL-1β, IL-6, and TNF-α were all measured as markers of inflammation at pretest and at 8-weeks.  Results: One-way ANOVA revealed no significant differences in IL-6 (p=.06), IL-1β (p=.18), and TNF-α (p=.20) between groups at baseline.  Additionally, no pretest differences existed between groups for age (p=.549), weight (p=.324), waist circumference (p=.086), gender (p=.591) and ethnicity (p=.875).   ANCOVA was calculated using compliance, age, gender, ethnicity, body weight, and waist circumference as covariates. No significant differences were discovered between groups after FO supplementation for IL-6 (p=.453), and TNF-α (p=.242).  A significant difference was discovered for IL-1β (p=.050) with lower levels in the FO group.  Conclusions:  The results of this study is in agreement with some previous studies that suggest that FO supplementation has no effect on plasma pro-inflammatory cytokines TNF-α or IL-6, but does have an effect on IL-1β in non-dialysis CKD patients.  The protective effects in this study and others are due primarily to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in FO.  Inflammation plays a significant role in cardiovascular disease in CKD patients with novel approaches needed to reduce the risk of cardiovascular disease.