The effects of fish oil supplementation on inflammation markers in chronic kidney disease patients.

Abstract

The purpose of this study was to investigate the effects of the daily consumption of fish oil, containing 2.4g of n-3 fatty acids (1400 mg Eicosapentaenoic acid + 1000 mg Docosahexaenoic acid), on pro-inflammatory cytokines, IL-1β, IL-6, and TNF-α for 8 weeks in CKD patients, stages 2-5. One prevalent characteristic of all stages of CKD is excessive production of these pro-inflammatory cytokines. Fish oil supplementation has been claimed to lower the levels of these pro-inflammatory cytokines, and as a result decrease the severity of inflammatory diseases. The benefits of fish oil supplementation for an extensive range of populations and a variety of health concerns are apparent, yet the anti-inflammatory benefits for stages 2-5 CKD patients are not as well documented. Consequently, continued studies in this area are clearly needed. Thirty-one individuals completed the current study, with 17 subjects in the fish oil group, while 14 subjects were included in the comparison group (safflower oil). Separate Repeated Measures ANOVAs were used to measure changes in the primary outcome variables using a 2 (fish oil or safflower oil) x 2 (time points) design. Significance level was set at p ≤ 0.05. The results of this study showed that fish oil supplementation does not decrease plasma pro-inflammatory markers TNF-α, IL-6, and IL-1β in CKD patients, stages 2-5. The analysis of TNF-α levels revealed no significant difference across time (p = 0.92) or between groups (p = 0.94). However, there was a group by time interaction, (p = 0.03). The analysis between IL-6 levels and treatment resulted in no significant difference across time (p = 0.30), between groups (p = 0.15), nor was there a significant group by time interaction with the trends across time differing by group membership (p = 0.82). Finally, the analysis between treatment and IL-1β resulted in no significant difference in IL-1β levels across time (p = 0.17), between groups (p = 0.26) nor treatment-by-time interaction either (p = 0.44). The supplementation of fish oil was not found to decrease markers of inflammation, but did demonstrate that a short-term administration of fish oil is well-tolerated by CKD patients, stages 2-5. But, further investigation is essential to better define the long-term impact of fish oil supplementation in this high-risk population.