Colorectal cancer (CRC) is the 4th most frequent type of tumour and the 2nd leading cause of malignancy-related deaths in the Western world. Worldwide CRC incidence is increasing in female patients, those younger than 50 years-old and in low/middle income nations. As ~50% of CRC cases are preventable (WCRF-UK and Cancer Research UK websites) there is a potential to significantly reduce CRC incidence and address this global clinical need. Many of the fundamental mechanisms which link nutritional intake to physiological consequences remain undetermined. An improved mechanistic understanding would form part of a wider robust evidence base which is important in determining cause-and-effect relationships. There is a need to answer fundamental questions about the mechanisms by which diet impacts upon the normal biological processes and how they link through to influences on health and disease. Primary prevention can be achieved with greater understanding of how the major CRC risk factors of diet and lifestyle impact on the intestinal stem cell from which CRC originates. Secondary prevention can be achieved with improvements in existing and new techniques for the early detection of the pre-malignant polyps prior to their progression to carcinoma.