Brewing Epigenetic Defense: Mechanisms of Coffee Bioactives in the Chemoprevention of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality, frequently arising from chronic inflammatory states such as metabolic dysfunction-associated steatotic liver disease and cirrhosis. While extensive epidemiological data demonstrate a strong, dose-dependent inverse association between habitual coffee consumption and HCC incidence, the underlying molecular causality remains incompletely understood. In this comprehensive review, we elucidate the “Coffee Paradox” through the lens of nutriepigenomics. We demonstrate how coffee-derived bioactives—specifically chlorogenic acids, diterpenes, and microbially derived short-chain fatty acids—function as a coordinated epigenetic defense system. These compounds actively inhibit DNA methyltransferases, serve as endogenous histone deacetylase inhibitors via the gut–liver axis, and induce post-transcriptional, tumor-suppressive microRNA networks to halt oncogenic progression. However, to provide a critical and balanced perspective, we also address significant translational challenges. We evaluate conflicting null associations from recent Mendelian randomization studies and highlight the profound variability introduced by specific brewing methods, roasting profiles, and individual pharmacogenomics (e.g., CYP1A2 polymorphisms). Finally, we outline the future of precision hepatology, emphasizing the critical transition from observational epidemiology to clinical application via the utilization of circulating exosomal microRNAs as dynamic liquid biopsies and the development of standardized epi-nutraceuticals. Ultimately, this multi-layered epigenetic framework provides a robust foundation for integrating targeted dietary interventions into the primary prevention of HCC.