Coffee Consumption and Cancer Risk; An Assessment of the Health Implications Based on Recent Knowledge

Abstract

A significant number of studies suggests that coffee consumption reduces cancer risk. This beneficial effect is usually ascribed to the presence of polyphenolic antioxidants and anti- inflammatory agents, including caffeine, cafestol, kahweol and chlorogenic acids. To summarize recent literature on this subject we performed a bibliographic search in PubMed and Embase over the period January 2005 to December 2020 to identify cohort studies and meta-analysis (with data collection ensuring quality of selected reports) that could provide quantitative data on the relationship between coffee consumption and common cancers. The totality of eligible scientific papers support the evidence that coffee intake is inversely associated with hepatocellular cancer risk and to a - slight extent- breast cancer risk among postmenopausal women. As to the association with other organs, including esophagus, pancreas, colorectum, kidneys, bladder, ovaries and prostate, the results are less clear as reports reveal conflicting results or statistically non- significant data. Therefore this overview does not allow broad- based conclusions. Important uncertainties include general study design, inhomogeneous patient sampling, different statistical analysis, (deliberate) misreporting of socio- economic status, education, coffee brewing methods, consumption caffeinated or decaffeinated coffee, smoking habits and alcohol intake. Obviously, more epidemiological research needs to be conducted before solid science- based recommendations can be made with regard to coffee consumption.