Non-alcohol-induced fatty liver disease (NAFLD) is a widespread chronic liver disease. It is considered a multifactorial disorder that can lead to liver fibrosis and is a global public health problem.
Previous studies suggested that coffee consumption might have a possible protective effect against NAFLD and liver fibrosis, but the results of the studies were inconsistent.
Against this background, American scientists have systematically analysed the results of eleven epidemiological studies. Their recently published work includes two meta-analyses.
The first meta-analysis examines the effect of coffee on the development of non-alcohol-induced fatty liver disease in those who drank or did not drink coffee. This analysis involved 71,787 participants aged between 20 and 70 years. The subjects were asked about their coffee consumption in a questionnaire. The second meta-analysis compares the risk of developing liver fibrosis in NAFLD patients who consumed coffee or did not drink coffee. Here 1,338 subjects between 20 and 70 years of age who had already been diagnosed with non-alcohol-induced liver disease took part.
Results of the two analyses show the following:
The NAFLD risk was significantly lower among coffee drinkers compared to those who did not consume coffee. The researchers also found a significantly reduced risk of liver fibrosis in NAFLD patients who drank coffee compared to those who did not.
The authors discuss the reasons for the possible liver-protective effects. Ingredients in coffee, such as caffeine, chlorogenic acids, potassium, niacin (vitamin B3), diterpenes and the coffee oils cahweol and cafestol could mediate antioxidant, anti-inflammatory and anti-fibrosis effects.
The scientists concluded that regular coffee consumption is associated with a significant reduction in the risk of NAFLD. It is also significantly associated with a reduced risk of developing liver fibrosis in previously diagnosed NAFLD patients.
Whether coffee consumption could be considered a preventive measure for NAFLD and liver fibrosis needs to be investigated in further epidemiological studies.
Umar Hayat, Ali A. Siddiqui, Hayrettin Okut, Saba Afroz, Syed Tasleem, Ahmed Haris, The effect of coffee consumption on the non-alcoholic fatty liver disease and liver fibrosis: a meta-analysis of eleven epidemiological studies, Annals of Hepatology (2020), doi: doi.org/10.1016/j.aohep.2020.08.071