Adherence to the World Cancer Research Fund/American Institute for Cancer Research Recommendations and Colorectal Cancer Risk in Morocco: A Case-Control Study

Abstract

Background: Currently, colorectal cancer (CRC) incidence and mortality were rising in African countries; these rates are alarming and should be considered to make prevention policies. The World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) released 8 recommendations on body fatness, physical activity and diet to prevent against cancer development. Aim: The current study was designed to evaluate the association between the WCRF/AICR recommendations and the risk of CRC in a case-control study among Moroccan adults. Methods: A case-control study was conducted in 5 Moroccan hospital centers, including 1516 cases and 1516 controls. The study was matched on sex, age (± 5 years) and center. The habitual diet was assessed with a validated food frequency questionnaire. Adherence to WCRF/AICR recommendations was evaluated through a score that incorporates 6 components (body fatness, physical activity, foods and drinks that promote weight gain, plant foods, animal foods, alcoholic drinks). Each related component recommendation was rated using a score of 2 levels: (1) when the recommendation was met; (0.5) when the recommendation was partially met; (0) when the recommendation was not met. The overall WCRF/AICR score ranged from 0 (no adherence to WCRF/AICR guidelines) to 6 (high adherence). To categorize this score, we calculated the tertile cut-offs of controls (reference population) for both sexes (men and women separately) that we applied on the whole population. Conditional logistic regression was used to calculate ORadjusted and its 95% confidence intervals adjusted for age, residence, education level, monthly income, family history of CRC, smoking status, BMI, physical activity, total energy intake, and alcohol intake unless the variable was part of recommendation under evaluation. Results: CRC risk was significantly reduced with increasing adherence to each WCRF/AICR recommendation: for body fatness (ORa = 0.47; 95% CI, 0.36-0.63), physical activity (ORa = 0.33; 95% CI, 0.24-0.45), sugary drinks (ORa = 0.58, 95% CI, 0.42-0.80), plant foods (ORa = 0.18; 95% CI, 0.12-0.29) and animal foods (ORa = 0.47; 95% CI, 0.36-0.62). Also a significant inverse association was observed for the highest category of adherence to WCRF/AICR guidelines for CRC risk (ORa = 0.29; 95% CI, 0.23-0.37) compared with the lowest category. Conclusion: The WCRF/AICR index including a combination of 6 components showed strong protective associations for CRC risk in Morocco. These results confirm the importance of promoting the WCRF guidelines among the Moroccan population to prevent CRC incidence.