Cancer is a leading cause of death worldwide. The Western dietary pattern is an established risk factor for many cancers, particularly for colorectal cancer (CRC). The Western diet is typified by the high consumption of red and processed meats, high fat foods, sugary foods and refined grains, whereas a more prudent diet replaces these foods with whole grains, fruits and vegetables, many of which are rich in dietary bioactives known to reduce cancer risk. Agricultural production of many of the foods common to the Western diet is also estimated to have a high environmental impact. Thus, diet modification to reduce cancer risk by consumption of more fruits and vegetables would also be considered a more environmentally sustainable diet.
This review summarizes the impact of dietary bioactives on gastrointestinal health, with a focus on the role of the gut microbiome and intestinal inflammation in colorectal carcinogenesis. Four dietary bioactives with purported anti-cancer activities are discussed, including catechins (green tea), anthocyanins (red/blue berries), proanthocyanidins (cocoa) and isoflavones (soy), with special consideration given to evidence for their interaction with the gut microbiome. The review concludes with a proposed model for investigating the impact of dietary bioactives for prevention of colon cancer that incorporates the Western nutritional pattern and considers the role of human gut microbiota in pre-clinical studies.
2015 by Agricultural and Forestry Research Center, University of Tsukuba