Adherence to World Cancer Research Fund and the American Institute for Cancer Research cancer prevention recommendations and reduction in breast cancer risk: results of a large-scale case–control study in Morocco

Limited evidence exists on the combined effects of lifestyle factors on breast cancer (BC) risk, particularly in developing countries. This study aimed to investigate the association between adherence to the World Cancer Research Fund and the American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations and BC risk among Moroccan women. We conducted a large case-control study including 1,400 cases and 1,400 matched controls (by age and place of residence) between 2019 and 2023. A structured general questionnaire and a validated Food Frequency Questionnaire were used for data collection. Adherence to cancer prevention recommendations was assessed using a score ranging from 0 to 7, comprising seven components covering dietary patterns, physical activity, healthy weight, and breastfeeding. Multivariable logistic regression models were used to estimate OR and 95 % CI, accounting for potential confounding variables. For each one-point increase in the WCRF/AICR adherence score, the odds of BC decreased by 67 % overall (OR = 0·33; 95 % CI: 0·29-0·37). This inverse association was consistent among both premenopausal women (OR = 0·29; 95 % CI: 0·24-0·35) and postmenopausal women (OR = 0·35; 95 % CI: 0·30-0·41). Analysis of individual recommendations indicated that physical activity, maintaining a healthy weight, breastfeeding, consuming a plant-rich diet, and limiting the intake of fast and other processed foods were the main drivers of the observed inverse association with BC. In conclusion, greater adherence to the WCRF/AICR recommendations is associated with a reduced risk of breast cancer in Morocco. Prevention strategies should incorporate comprehensive interventions targeting multiple lifestyle factors.