Evidence Hub

Inverse Association between the Omega-3 Index and Neutrophil-Lymphocyte Ratio: Pooled Results from Four Supplementation Trials

McBurney MI, Tintle NL, Westra J, Plourde M, Flock M, Mutch DM, Stephensen CB, Newman JW et al.

The Journal of nutrition, 2026

436 participants

Abstract

Background: The Omega-3 Index [O3I, erythrocyte eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) content] has been inversely correlated with neutrophil-lymphocyte ratio (NLR) and red blood cell distribution width (RDW) in observational studies.

Objectives: We evaluated the effects of omega-3 interventions (EPA+DHA) on O3I, NLR, and RDW values in healthy adults and tested the hypothesis that changes in O3I (ΔO3I) modified NLR and, separately, RDW.

Methods: We performed a de novo, individual-level analysis of baseline (b) and post (p) intervention O3I, NLR, and RDW values from 3 randomized, placebo-controlled trials and 1 ω-3 supplementation trial, followed by an equivalent duration washout (combined n =436). Primary outcome effect estimates were obtained using linear mixed effects models with a statistical significance threshold set at 0.05.

Results: EPA + DHA supplementation (mean dose = 1160 mg/d) increased O3I (ΔO3I = 3.28%, P < 0.001, n = 253), whereas O3I decreased (ΔO3I = -0.62, P < 0.001, n = 183) in the CONTROL group. NLR decreased in individuals treated with EPA + DHA (ΔNLR = -0.15, P < 0.001) compared with CONTROL (-0.02, 95% confidence interval: -0.10, 0.06), a statistically significant difference (P < 0.05). In contrast, EPA+DHA supplementation was not associated with changes in RDW (P = 0.62), whereas RDW increased by ∼1% in CONTROL individuals (ΔRDW = 0.09, P < 0.01). ΔNLR values were inversely correlated with ΔO3I in unadjusted (model 1, r = -0.08, P…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 436 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free