Extended healthy lifestyle index and colorectal cancer risk in the Moroccan population.

Purpose: Little is known about the combined effect of different lifestyle factors on CRC incidence among populations living in developing countries. In this study, we sought to create an Extended Healthy Lifestyle Index (EHLI) and to investigate its association with CRC risk in the Moroccan population.

Methods: A large case-control study including 1516 cases and 1516 controls, matched on age, sex and center were recruited in 5 Moroccan university hospital centers between 2009 and 2017. EHLI scores, including 9 modifiable factors (smoking, alcohol consumption, physical activity intensity, BMI, fruit and vegetables consumption, drinks that promote weight gain, red and processed meat, relatively unprocessed cereals and/or pulses, and dairy products consumption) were assigned to lifestyle information derived from the participants. We assessed the score based on the answers on each of the nine lifestyle components as unhealthy/un-compliant (0 point), healthy/compliant (1 point) and 0.5 for partial compliance to the recommendation. Conditional logistic regression models were used to assess the association between the EHLI and CRC risk and to estimate multivariate ORs and their 95% confidence intervals (CIs). All potential confounder variables were considered.

Results: After adjusting for potential confounding factors, a significant decrease in the risk of overall CRC was observed when comparing the highest EHLI category with the lowest index category (0.39, 95% CI: 0.33-0.47). These results did not differ by colon or rectum subsite.

Conclusion: Combined healthy lifestyle factors are associated with a significantly lower incidence of CRC in Moroccan populations. Prevention strategies should consider targeting of multiple lifestyle factors.