Dietary habits and breast cancer in South Asian females: a systematic review

Breast cancer is the fifth-leading cause of cancer-related mortality in women globally. Asia has a lower overall incidence of breast cancer compared to global incidence rates. Unique dietary habits observed in South Asians might have contributed significantly towards these low incidence rates. This review aims to explore the association between dietary habits and breast cancer among South Asian women. A systematic review was conducted according to the PRISMA guidelines using five electronic databases: MEDLINE, EMBASE, CINAHL, Web of Science, and Scopus. Additional articles were searched in Google Scholar and the reference list of the selected articles. Review questions were framed according to the PECOS framework. South Asian women above 18 years of age diagnosed with breast cancer were the population of interest. Only the studies reported in the English language were included without date limits. Screening and quality assessment were done by two independent reviewers using Joanna Briggs Institute critical appraisal tools. The final review included 12 articles. The findings revealed heterogeneous associations between dietary habits and breast cancer risk. Plant-based foods such as fruits, vegetables, legumes, soy products, and mushrooms were generally associated with a reduced risk, while red meat and high-fat foods were linked to increased risk. Dairy products and protein intake showed mixed results, and fish consumption had no significant association. Variations in findings are likely influenced by differences in dietary habits, cultural practices, and methodological approaches across studies. Despite heterogeneity in methods and a lack of meta-analytic synthesis, the review supports the protective role of plant-based diets and highlights dietary habits as modifiable risks for breast cancer. Public health strategies should promote consumption of minimally processed, fiber-rich plant- based foods and reduce intake of red and processed meats and high-fat products. Further region-specific, standardized research is needed to refine dietary interventions for breast cancer prevention. CRD42023464682.