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

Grants and funding

The study was supported by a grant from National High Technology Research and Development Program of China (No. N20080753), the National Natural Science Foundation of China (No. 30972464) and the Ph.D. Programs Foundation of Ministry of Education of China (No. 20070335025). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.