Prevention of parenteral nutrition-associated liver disease: role of ω-3 fish oil

Purpose of review Parenteral nutrition-associated liver disease (PNALD) is the most severe complication of long- term parenteral nutrition. Its cause remains unclear, although recent studies suggest that the omega-6 polyunsaturated fatty acids in plant oil-based lipid emulsions and the associated phytosterols contribute to the development of hepatotoxicity. In contrast, fish oil-based lipid emulsions are composed mainly of omega-3 polyunsaturated fatty acids and are hypothesized to be hepatoprotective. This review will discuss fish oil-based lipid emulsions in the prevention of PNALD. Recent findings In several animal models of PNALD, the use of an intravenous fish oil-based lipid emulsion improved parenteral nutrition-associated cholestasis without resultant essential fatty acid deficiency or growth impairment. Following these results and preliminary human data, an open trial for compassionate use was initiated, followed by a randomized controlled trial to evaluate the current management of pediatric PNALD. To date, at the author's institution, more than 130 children with PNALD have been treated with Omegaven, a fish oil-based emulsion, with improved liver function among most patients. Summary PNALD remains the most severe complication of long-term parenteral nutrition with an unclear pathophysiology. However, the use of a fish oil-based emulsion appears efficacious and hepatoprotective.