Is Moderate Alcohol Use in Non-Alcoholic Fatty Liver Disease Good or Bad? A Critical Review.

Moderate alcohol consumption in patients with nonalcoholic fatty liver disease (NAFLD) is common, yet the effects on cardiovascular and liver health are unclear. Moderate alcohol use is associated with improved insulin sensitivity and decreased cardiovascular mortality in the general population but whether similar benefits are seen in persons with NAFLD is largely unstudied. There is significant overlap in the pathogenesis of alcoholic liver disease (ALD) and NAFLD although studies of ALD have focused on pathologic alcohol intake and few mechanistic studies of moderate alcohol use in NAFLD exist. We undertook a critical review of the effect of moderate alcohol use on cardiovascular and liver disease in patients with NAFLD. A total of 7 observational studies met criteria for inclusion (one for cardiovascular endpoints and 6 for liver endpoints). There were insufficient studies to assess the association with cardiovascular outcomes. There was a positive association between moderate alcohol use and decreased NASH and fibrosis, however heavy episodic drinking may accelerate fibrosis progression and in patients with advanced fibrosis moderate alcohol use may increase the risk of hepatocellular carcinoma. Significant methodologic limitations were present including incomplete adjustment for confounders and failure to measure lifetime use or the pattern of alcohol intake. Thus, a strong recommendation of benefit of moderate alcohol use in NAFLD cannot be made. There remains a need for additional high quality longitudinal studies that evaluate both cardiovascular and liver outcomes among NAFLD patients with moderate or lesser degrees of alcohol use. This article is protected by copyright. All rights reserved.