Diet and Colon: What Matters?

Pan Pan; Jianhua Yub; Li-Shu Wang


Curr Opin Gastroenterol. 2019;35(2):101-106. 

In This Article

Abstract and Introduction


Purpose of review: Colorectal cancer (CRC) is one of the most common cancers and the fourth leading cause of cancer-related deaths worldwide. Diet has a significant impact on the risk of developing CRC, but though processed meat is a known positive contributor, the effects of other dietary components are largely mixed. This review focuses on dietary patterns to describe the complexity of dietary diversity and overall food consumption and to examine the relationship between dietary patterns and risk of CRC.

Recent findings: After searching human studies published in 2017–2018, we selected and evaluated 30 articles, including meta-analyses, cohort studies, and prospective studies. These studies suggest that the prudent or Mediterranean dietary pattern significantly decreases the risk of CRC compared to the Western dietary pattern; a lower dietary inflammatory index or a higher dietary quality index associates with a lower risk of CRC; closely following all aspects of the World Cancer Research Fund/American Institute for Cancer Research cancer prevention guidelines and recommendations correlates with a reduced risk of CRC.

Summary: The risk of developing CRC can be reduced by adopting a healthier lifestyle. More studies of the impact of diet on clinical outcomes of CRC are needed.


Colorectal cancer (CRC) is the third most common cancer in men, the second in women,[1] and the fourth leading cause of cancer-related deaths worldwide.[2] The incidence of CRC varies greatly among countries and correlates with indices of economic development. More developed countries in Oceania and Europe have a higher incidence of CRC, whereas Africa and Asia have a lower incidence.[1,2] With advances in early screening and treatment, the incidence of CRC is stabilizing or even decreasing in more developed countries, though it still ranks among the highest among cancer types. However, the silver lining is that CRC is largely preventable and that diet has a great impact on the risk of developing the disease.

The World Cancer Research Fund (WCRF) and American Institute for Cancer Research (AICR) publish and continuously update global reports of cancer data.[2] In addition, our previous review summarized major epidemiologic studies and examined the relationship between CRC incidence and various dietary components such as red/processed meat, fish, fiber, and fruits and vegetables.[1] Other than red/processed meat – whose positive contributions to CRC have been confirmed by several recent studies[3–6] – findings for other dietary components are mixed and controversial.[1,2] However, it is likely that a dietary pattern – rather than a single food – may significantly influence the incidence and outcomes of CRC. Thus, the current review updates the findings on dietary patterns and risk of CRC. We conducted a PubMed search for human studies published from January 2017 to September 2018, using key words including CRC, diet, nutrition, and epidemiology. Articles that described and compared the impact of diets on CRC were screened and selected for eligibility. Collectively, 30 publications were examined. These studies suggest that a healthy dietary pattern, a lower dietary inflammatory index (DII), or greater adherence to the WCRF/AICR guidelines contribute to a lower risk of developing CRC.