Light and moderate alcohol consumption significantly reduces the prevalence of fatty liver in the Japanese male population.

Objectives: The effect of alcohol consumption on the liver is controversial. Recent reports have suggested that moderate alcohol consumption decreases the prevalence of elevated alanine aminotransferase levels. The role of alcohol consumption in the development of fatty liver (FL), however, has not been studied definitively. The aim of this study was to examine the association between alcohol consumption and FL in a large Japanese population.

Methods: A total of 7,431 asymptomatic male subjects who underwent a complete medical survey in our institute between May 2007 and July 2008 were recruited. Cases positive for hepatitis B or C viruses, potential hepatotoxic drug intake, or under treatment for metabolic disorders were excluded. FL was defined by ultrasonography. Visceral and subcutaneous adipose tissues (VAT and SAT) were measured by computed tomography. Independent and significant predictors associated with FL were determined by multiple logistic regression analysis.

Results: Of the initial study candidates, 130 (1.7%) were positive for hepatitis B and 66 (0.8%) were positive for hepatitis C. On the basis of the inclusion and exclusion criteria, 5,599 men (50.9+/-8.1 years) were studied cross-sectionally. Light (40-140 g/week) and moderate (140-280 g/week) alcohol consumption significantly and independently reduced the likelihood of FL (odds ratio=0.824 and 0.754, 95% confidence interval=0.683-0.994 and 0.612-0.928, P=0.044 and 0.008, respectively) by multivariate analysis after adjusting for potential confounding variables. VAT, SAT, low-density lipoprotein, triglycerides, and fasting blood glucose were significant predictors of the increased prevalence of FL, whereas age was a predictor of the decreased prevalence of FL.

Conclusions: The prevalence of FL was significantly and independently decreased by light and moderate alcohol consumption in men of an asymptomatic Japanese population.