Coffee phytochemicals and their protective roles in hepatic and renal disorders: a review

Coffee is a chemically complex beverage containing hundreds of bioactive compounds, including caffeine, chlorogenic acids, and diterpenes, that influence health through diverse biochemical pathways. This review brings together coffee chemistry with emerging knowledge on bioavailability, metabolic transformation, and the role of gut microbiota-derived metabolites. Recent epidemiological and clinical evidence is systematically summarized, linking coffee consumption to reduced risks of chronic liver disease, hepatocellular carcinoma, nonalcoholic fatty liver disease, and chronic kidney disease. Particular attention is given to the physiological relevance of metabolite concentrations, highlighting how protective effects may stem from circulating derivatives rather than parent compounds. We also consider the influence of preparation methods and interindividual variability on health outcomes. By integrating chemical, metabolic, and clinical perspectives, this synthesis provides a food-science-oriented framework that reconciles in vitro findings with human evidence, advancing a more nuanced understanding of coffee's multifaceted effects and their implications for hepatic and renal health.