Both dietary fatty acids and alcohol play an important role in the pathogenesis of alcoholic liver disease. Findings of studies in rats show a steatogenic role for dietary fat. A role for polyunsaturated fatty acids in alcoholic liver disease is supported by results of studies, which show that pathologic changes occur only in rats fed ethanol with polyunsaturated fatty acids. The mechanisms through which the fatty acids promote alcoholic liver disease include enhanced oxidative stress, production of endotoxin, and increased expression of proinflammatory cytokines.