Dietary Patterns and Breast Cancer Risk: A Systematic Review

Background/Aim: The association of dietary patterns representing multiple dietary components and breast cancer risk is not clearly understood. Our objective was to conduct a systematic review of the association between dietary patterns and breast cancer risk. Materials and Methods: The original articles included, were published between January 2013 and May 2017 and characterized diets using a priori and posteriori approaches to examine associations between dietary patterns and breast cancer risk. A novel scoring matrix was used to grade posteriori dietary pattern alignment with the American Cancer Society dietary guidelines. Results: Seventeen case-control and nested case-control studies identified 15 healthy, and 10 unhealthy, dietary patterns determined posteriori, and 7 dietary indices determined a priori. Vegetables were consistently found in breast cancer protective patterns whereas saturated fat and red and processed meats were consistently found in patterns associated with increased breast cancer risk. Conclusion: Findings suggest that dietary patterns that include vegetables and limit saturated fat and red and processed meats may lower breast cancer risk.