title: ω-3 fatty acids, γ-linolenic acid, and antioxidants: immunomodulators or inert dietary supplements?
abstract: BACKGROUND
  The omega-3 (n-3) fatty acids docosahexaenoic acid and eicosapentaenoic acid, along with γ-linolenic acid and antioxidants, may modulate systemic inflammatory response and improve oxygenation and outcomes in patients with acute lung injury.
  
  
  METHODS
  Objective: To determine if dietary supplementation of these substances to patients with acute lung injury would increase ventilator-free days to study day 28. Design: The OMEGA study, a randomized, double-blind, placebo-controlled, multicenter trial conducted from January 2, 2008, through February 21, 2009. All participants had complete follow-up. Setting: This trial occurred at 44 hospitals in the National Heart, Lung, and Blood Institute ARDS Clinical Trials Network. Subjects: Participants were 272 adults within 48 hours of developing acute lung injury requiring mechanical ventilation whose physicians intended to start enteral nutrition. Intervention: Twice-daily enteral supplementation of n-3 fatty acids, γ -linolenic acid, and antioxidants compared with an isocaloric control. Enteral nutrition, directed by a protocol, was delivered separately from the study supplement. Outcomes: Ventilator-free days to study day 28.
  
  
  RESULTS
  The study was stopped early for futility after 143 and 129 patients were enrolled in the n-3 and control groups. Despite an 8-fold increase in plasma eicosapentaenoic acid levels, patients receiving the n-3 supplement had fewer ventilator-free days (14.0 vs 17.2; P=.02) (difference, −3.2 [95% CI, −5.8 to −0.7]) and intensive care unit-free days (14.0 vs 16.7; P=.04). Patients in the n-3 group also had fewer nonpulmonary organ failure-free days (12.3 vs 15.5; P=.02). Sixty-day hospital mortality was 26.6% in the n 3 group vs 16.3% in the control group (P=.054), and adjusted 60-day mortality was 25.1% and 17.6% in the n-3 and control groups, respectively (P=.11). Use of the n-3 supplement resulted in more days with diarrhea (29% vs 21%; P=.001).
  
  
  CONCLUSIONS
  Twice-daily enteral supplementation of n-3 fatty acids, γ-linolenic acid, and antioxidants did not improve the primary end point of ventilator-free days or other clinical outcomes in patients with acute lung injury and may be harmful.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Schott
authors.forename: David T
authors.initials: DT
authors.lastname: Huang
mesh_terms: D055371:Acute Lung Injury / Q000188:drug therapy*; D000975:Antioxidants / Q000627:therapeutic use*; D004281:Docosahexaenoic Acids / Q000627:therapeutic use*; D015118:Eicosapentaenoic Acid / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D015300:Ventilator Weaning; D017965:gamma-Linolenic Acid / Q000627:therapeutic use*
chemical_list: D000975:Antioxidants; D004281:Docosahexaenoic Acids; D017965:gamma-Linolenic Acid; D015118:Eicosapentaenoic Acid