The therapeutic potential of long-chain omega-3 fatty acids in nonalcoholic fatty liver disease

Objectives: The pharmacologic approach to disease management has not (as of yet) demonstrated safety and efficacy in nonalcoholic fatty liver disease (NAFLD). The current article introduces the long-chain omega-3 polyunsaturated fatty acids (LC-ω3s), and reviews the evidence and mechanisms by which their increased intake or supplementation may ameliorate NAFLD. Methods: A literature search was performed through Ovid Medline, using such terms as NAFLD, NASH, nonalcoholic, steatosis, polyunsaturated fatty acids, fish oil and omega-3. Results: The LC-ω3s display pleiotropic properties that are of benefit in cardiovascular disease. Deficiency of omega-3 fatty acids results in hepatic steatosis, whereas fish oil displays powerful hypotriglyceridemic properties. Intake and/or metabolism of omega-3 fatty acids are commonly impaired in NAFLD patients. A number of pre-clinical and clinical studies have demonstrated an ameliorative effect of supplemental fish oil, seal oil and purified LC-ω3s in reducing hepatic lipid content in NAFLD. There is less evidence that hepatic inflammation and fibrosis are safely reduced by LC-ω3s. Conclusions: Supplementation of LC-ω3s appears to safely reduce nutritional hepatic steatosis in adults. Whether other histopatholgic features of NAFLD also respond to LC-ω3s is being addressed by clinical trials. Any recommendation for omega-3 supplementation in NAFLD/NASH is contingent on these results.