Daily coffee: safeguard against liver injury?

A growing body of epidemiological and experimental evidence suggests that coffee may exhibit protective effects on the liver, and thus prevent or reduce the risk of liver damage. The aim of this research was to identify and review original investigations, which characterize the association between coffee consumption and serum alanine aminotransferase (ALT), a common marker of liver injury. A literature search was conducted via an electronic search of the PubMed database between years 1993 and 2015. Twelve observational studies were identified, eleven of which demonstrated a significant inverse association between coffee intake and serum ALT. In contrast, three experimental studies from one week to 6 months in duration report a rise in serum ALT with coffee consumption. In summary, many current research findings appear to support that consistent and/or high coffee consumption is associated with a decreased risk of elevated serum ALT. Additional experimental research is warranted to further explore possible contributors of the underlying mechanism of protection, which is poorly understood.