Effect of marine-derived n-3 polyunsaturated fatty acids on C-reactive protein, interleukin 6 and tumor necrosis factor α: a meta-analysis

PLoS One. 2014 Feb 5;9(2):e88103. doi: 10.1371/journal.pone.0088103. eCollection 2014.

Abstract

Background: Previous studies did not draw a consistent conclusion about the effects of marine-derived n-3 polyunsaturated fatty acids (PUFAs) on fasting blood level of C-reactive protein (CRP), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α).

Methods and findings: A comprehensive search of Web of Science, PubMed, Embase and Medline (from 1950 to 2013) and bibliographies of relevant articles was undertaken. Sixty-eight RCTs with a total of 4601 subjects were included in the meta-analysis. Marine-derived n-3 PUFAs supplementation showed a lowering effect on Marine-derived n-3 PUFAs supplementation had a significant lowering effect on TNF-α, IL-6 and CRP in three groups of subjects (subjects with chronic non-autoimmune disease, subjects with chronic autoimmune disease and healthy subjects). A significant negative linear relationship between duration and effect size of marine-derived n-3 PUFAs supplementation on fasting blood levels of TNF-α and IL-6 in subjects with chronic non-autoimmune disease was observed, indicating that longer duration of supplementation could lead to a greater lowering effect. A similar linear relationship was also observed for IL-6 levels in healthy subjects. Restricted cubic spline analysis and subgroup analysis showed that the lowering effect of marine-derived n-3 PUFAs on CRP, IL-6 and TNF-α in subjects with chronic non-autoimmune disease became weakened when body mass index was greater than 30 kg/m². The effect of marine-derived n-3 PUFAs from dietary intake was only assessed in subjects with chronic non-autoimmune disease, and a significant lowering effect was observed on IL-6, but not on CRP and TNF-α.

Conclusions: Marine-derived n-3 PUFAs supplementation had a significant lowering effect on CRP, IL-6 and TNF-α level. The lowering effect was most effective in non-obese subjects and consecutive long-term supplementation was recommended.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Animals
  • Autoimmune Diseases / blood
  • Autoimmune Diseases / immunology
  • C-Reactive Protein / analysis*
  • C-Reactive Protein / immunology
  • Chronic Disease
  • Dietary Supplements* / analysis
  • Eating
  • Fatty Acids, Omega-3 / administration & dosage
  • Fatty Acids, Omega-3 / pharmacology*
  • Female
  • Fish Products
  • Fishes
  • Humans
  • Interleukin-6 / blood*
  • Interleukin-6 / immunology*
  • Male
  • Middle Aged
  • Tumor Necrosis Factor-alpha / blood*
  • Tumor Necrosis Factor-alpha / immunology
  • Young Adult

Substances

  • Fatty Acids, Omega-3
  • Interleukin-6
  • Tumor Necrosis Factor-alpha
  • C-Reactive Protein