Coffee as chemoprotectant in fatty liver disease: caffeine-dependent and caffeine-independent effects.

Coffee consumption is associated with a variety of positive health outcomes in patients with chronic liver disease, including decreased liver-related mortality. The evidence for this has come from a wide variety of epidemiological studies over the past decade and remains consistent. Because coffee contains a large number of constituent molecules, many of which vary based on coffee source, roasting approach, and preparation, it has been difficult to identify the mechanisms by which coffee improves liver-related health. The caffeine hypothesis suggests that the primary active ingredient in coffee in this context is caffeine, which is an antagonist of liver adenosine receptors. However, some lines of data suggest caffeine-independent effects as well. This review examines the biological plausibility for caffeine-independent effects in the context of a recent publication in this journal.