Effects of omega-3 fatty acid supplementation on neurocognitive functioning and mood in deployed U.S. soldiers: a pilot study

Mil Med. 2014 Apr;179(4):396-403. doi: 10.7205/MILMED-D-13-00395.


Omega-3 fatty acids (FAs) may have neuroprotective properties for psychological health and cognition. The objective of this study was to evaluate the effectiveness of omega-3 FAs (eicosapentaenoic + docosahexaenoic; Harris-Schacky [HS]-Omega-3 Index) on neuropsychological functioning among U.S. Soldiers deployed to Iraq. This randomized, double-blind, placebo-controlled trial included Soldiers between the ages of 18 and 55 years who were randomly assigned to either the active treatment group (n = 44) or placebo group (n = 34). Active treatment was 2.5 g per day of eicosapentaenoic + docosahexaenoic (Lovaza; GlaxoSmithKline, Research Triangle Park, North Carolina). The placebo was corn oil ethyl esters. HS-Omega-3 Index, a neurocognitive battery (Central Nervous System-Vital Signs, Morrisville, North Carolina), and psychological health scales were assessed at baseline and after 60 days of treatment. Although the results revealed that omega-3 FAs significantly increased the HS-Omega-3 Index (p = 0.001), there were no significant effects on indices psychological health and neurocognitive functioning by treatment group. Nevertheless, there was a significant inverse correlation between the changes in the HS-Omega-3 Index and daytime sleepiness (r = 0.30, p = 0.009). Short-term treatment with 2.5 g of omega-3 FAs did not alter measures of neurocognition or psychological health, but there was evidence of a relationship between omega-3 levels and daytime sleepiness.

Publication types

  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Affect / drug effects*
  • Cognition / drug effects*
  • Dietary Supplements*
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Fatty Acids, Omega-3 / administration & dosage*
  • Female
  • Humans
  • Male
  • Mental Health*
  • Middle Aged
  • Military Personnel*
  • Pilot Projects
  • United States
  • Young Adult


  • Fatty Acids, Omega-3