Adherence to Mediterranean dietary quality index and risk of breast cancer in adult women: a case-control study

BMC Womens Health. 2023 Mar 14;23(1):107. doi: 10.1186/s12905-023-02247-w.


Background: Breast cancer (BC) is the fifth most prevalent cause of cancer-related deaths in Iran. Given that the role of whole-diet on cancer risk is important, this study aimed to assess the association of MedDQI and breast cancer risk.

Methods: This hospital-based case-control study was performed on 150 women with pathologically confirmed breast cancer within the period of less than 3 months. Controls were 150 apparently healthy that were matched by age. Dietary data was collected using a validated questionnaire. To examine participants' adherence to MedDQI, the MedDQI was created according to foods and nutrients highlighted or minimized in the MedDQI construction.

Results: After adjusting for possible confounders, participants in the highest quartile of the MedDQI score had 55% lower odds of breast cancer than women in the bottom quartile (OR: 0.45, 95% CI: 0.21, 0.94, P trend: 0.02). Stratified analysis by menopausal status showed such association in postmenopausal women (OR: 0.24, 95% CI: 0.07, 0.8, P trend: 0.055) after controlling for age and energy intake.

Conclusion: The results showed an inverse association between adherence to the MedDQI and risk of breast cancer among Iranian women. More prospective studies are needed to confirm our results.

Keywords: Breast cancer; Case-control; MedDQI; Mediterranean dietary quality index; Risk.

MeSH terms

  • Adult
  • Breast Neoplasms*
  • Case-Control Studies
  • Diet
  • Energy Intake
  • Female
  • Humans
  • Iran / epidemiology
  • Risk Factors