Nutritional Risk and Protective Factors for Colorectal Cancer: A Knowledge Synthesis in North African Countries

For both sexes combined, colorectal cancer ranks third internationally. It is the second most common cause of cancer death. Significant associations between colorectal carcinogenesis and dietary habits have been confirmed by epidemiologic data from cancer research in different countries. In this context, we aim to review the published literature from North African countries investigating the associations between dietary factors and colorectal cancer. Through the PubMed, Scopus, sciencedirect, Web of Science and Springer databases, we conducted literature search using the following keywords: colorectal cancer, colorectal adenocarcinoma, risk factors, protective factors, nutrition, diet, Morocco, Algeria, Tunisia, Libya, Egypt, Sudan, and Mauritania. All papers with data related to the diet‒colorectal cancer association were selected without any restrictions regarding sample size, data sources, language or year of publication. A total of 21 retrospective papers were reviewed for relevant data extraction. Based on these findings, scientific consensus confirmed the association between diet and colorectal cancer. However, published data from North African countries remain insufficient and nuanced. Only processed meat, red meat, and alcohol were agreed as dietary risk factors and the Mediterranean diet, dairy products, whole grains, fruits and vegetables as dietary protective factors. Data on other dietary factors are inconsistent and sometimes paradoxical. This justifies the great interest in approaching this preventive dimension with more national, multicenter, prospective studies.