Current Evidence on Ω-3 Fatty Acids in Enteral Nutrition in the Critically Ill: A Systematic Review and Meta-Analysis

•Enteral fish oil confers anti-inflammatory and immunomodulatory effects.•No evidence was found for improved mortality from enteral fish oil supplementation among critically ill patients.•Intensive care unit length of stay and duration of ventilation was significantly shorter with fish oil; however, results were based on heterogeneous studies.•Reduced mortality in patients with acute respiratory distress syndrome was found; however, studies had low methodological quality.•Enteral fish oil supplementation cannot be recommended for critically ill patients.•Further research should focus on the association between the individual critically ill patients’ immune response, the administration of fish oil, and clinical outcomes.