Drinking moderate amounts of alcoholic beverages may protect from developing a fatty liver which has become an endemic disorder.
Non-alcoholic fatty liver disease (NAFLD) has become an endemic disorder. It is the most common liver disease, not only in the Western world but also in Asia. NAFLD is the consequence of a modern Western lifestyle: too much caloric intake together with too little physical activity are considered to be the major risk factors.
An estimated 20 to 40 % of adults in Western industrialized countries are affected. In adults who are overweight, this figure reaches already approximately 70 %. The fact that up to one third of overweight schoolchildren already have a fatty liver and that 80 % of patients with type 2 diabetes are inflicted with this lipid disorder is of particular concern.
NAFLD is of concern not only because it can develop into chronic inflammation of the liver, liver cirrhosis and liver cancer, but also because it leads directly to type 2 diabetes. In addition, a growing number of publications show that NAFLD is associated with an increased risk of heart disease, independently of all known risk factors for heart disease.
Whereas many studies have identified a high intake of alcoholic beverages as a risk factor for alcoholic liver disease, recent cross-sectional studies have demonstrated that moderate consumption of alcoholic beverages, and in particular wine consumption, is associated with a decreased risk for NAFLD. Recent prospective cohort studies have found a decreased incidence of NAFLD with moderate alcohol and wine intake.
Whether and to what extent this seemingly paradoxical relation is causally related has not been clearly established so far. Possible mechanisms that could explain this phenomena, could be an increase in insulin sensitivity and the anti-inflammatory effects of alcohol per se as well as the effects of the many polyphenolic substances in wine and other alcoholic beverages. Resveratrol, for example, is capable to inhibit the transcription factor SREBP-1c which is responsible for the formation of lipids from carbohydrates in the liver.
Thus, it may turn out that the preventive effect of moderate regular wine consumption is also related to less fat accumulation in the liver.
A Japanese study analyzed the longitudinal relationship between drinking pattern and non-alcoholic fatty liver disease (NAFLD). 5297 Japanese individuals (3773 men and 1524 women) who participated at a baseline study in 2003 were included and followed up at least once from 2004 to 2006. At follow-up, in 13.4 % of men and 7.8 % of women, a newly developed fatty liver was observed. Men drinking light and moderate amounts of alcohol had a significantly reduced risk of developing NAFLD, and even consuming more than 280 g/week was still inversely associated with fatty liver after adjusting for obesity, exercise, and smoking. In women, drinking 0.1-69.9 g/week and drinking 70.0-139.9 g/week was inversely associated with developing a fatty liver.
Moriya A, Iwasaki Y, Ohguchi S, et al. Roles of alcohol consumption in fatty liver: A longitudinal study. J Hepatol. 2014 Nov 27. [Epub ahead of print]
For more information about this article, read the scientific abstract here.