A Comprehensive Overview of the Risks and Benefits of Coffee Consumption.

Findings on both the health benefits and the potentially harmful effects of coffee consumption have been contradictory. However, the general scientific consensus is that moderate, regular coffee drinking by healthy individuals is either essentially benign or mildly beneficial.  Results and generalizations are complicated by a number of factors, including differences in age, gender, health status, type of coffee preparation, serving size, and source of coffee. Coffee may have potential health benefits and risks, but causality cannot be established for either with the research currently available as these are largely based on observational data.  This review aimed to provide a comprehensive overview of the risks and benefits of coffee consumption on health outcomes.  A systematic search (search terms: "coffee" OR "coffee adj3" [consum* or intake* or drink*]) of the literature (from 1970; humans; in English) using the electronic databases "OVID," "CINAHL," and "Web of Knowledge" returned 12405 results. Duplicates were removed, studies were screened (based on inclusion/exclusion criteria), and the remaining eligible studies (n = 1277) were used to collate an exhaustive list of the potential health benefits and risks of coffee consumption, which were grouped and are discussed with regard to major diseases/conditions (mortality, cardiovascular disease, cancer, and metabolic/liver/neurological disorders), at-risk/vulnerable groups, and specific coffee constituents. This qualitative assessment has shown that the health benefits (or null effects) clearly outweigh the risks of moderate coffee consumption in adult consumers for the majority of health outcomes considered. Results from this research may aid further qualitative and quantitative deterministic risk-benefit assessments of coffee consumption.