The role of dietary polyphenols in the moderation of the inflammatory response in early stage colorectal cancer

Current focus in colorectal cancer (CRC) management is on reducing overall mortality by increasing the number of early-stage cancers diagnosed and treated with curative intent. Despite the success of screening programs in down-staging CRC, interval cancer rates are substantial and other strategies are desirable. Sporadic CRC is largely associated with lifestyle factors including diet. Polyphenols are phytochemicals ingested as part of a normal diet, which are abundant in plant foods including fruits/berries and vegetables. These may exert their anti-carcinogenic effects via the modulation of inflammatory pathways. Key signal transduction pathways are fundamental to the association of inflammation and disease progression including those mediated by NF-κB and STAT, PI3K and COX. Our aim was to examine the evidence for the effect of dietary polyphenols intake on tumor and host inflammatory responses to determine if polyphenols may be effective as part of a dietary intervention. There is good epidemiological evidence of a reduction in CRC risk from case-control and cohort studies assessing polyphenol intake. It would be premature to suggest a major public health intervention to promote their consumption; however, dietary change is safe and feasible, emphasizing the need for further investigation of polyphenols and CRC risk.