Review article: Coffee consumption, the metabolic syndrome and non-alcoholic fatty liver disease

Abstract

Background Coffee consumption may modulate the risk of the metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD). Aim To review the experimental, epidemiological and clinical studies investigating the association between coffee consumption and the risk of MetS and NAFLD. Methods A literature search was conducted with the aim of finding original experimental, epidemiological and clinical articles on the association between coffee consumption, MetS and NAFLD. The following databases were used: PubMed, Embase, Scopus and Science Direct. We included articles written in English and published up to July 2013. Results Three experimental animal studies investigated the effects of coffee in the MetS, whereas five examined whether experimental coffee intake may modulate the risk of fatty liver infiltration. All of the animal studies showed a protective effect of coffee towards the development of MetS and NAFLD. Moreover, we identified eleven epidemiological and clinical studies that met the inclusion criteria. Of them, six were carried out on the risk of the MetS and five on the risk of NAFLD. Four of the six studies reported an inverse association between coffee consumption and the risk of MetS. The two studies showing negative results were from the same study cohort consisting of young persons with a low prevalence of the MetS. All of the epidemiological and clinical studies on NAFLD reported a protective effect of coffee intake. Conclusions Coffee intake can reduce the risk of NAFLD. Whether this effect may be mediated by certain components of the MetS deserves further investigation. © 2013 John Wiley & Sons Ltd.