Iron intake with the risk of breast cancer among Chinese women: a case-control study

Objective: The current study evaluated the associations between different forms and sources of Fe and breast cancer risk in Southern Chinese women. Design: Case-control study. We collected data on the consumption of Fe from different forms and food sources by using a validated FFQ. Multivariable logistic regression and restricted cubic spline (RCS) analysis was used to reveal potential associations between Fe intake and breast cancer risk. Setting: A case-control study of women at three major hospitals in Guangzhou, China. Participants: From June 2007 to March 2019, 1591 breast cancer cases and 1622 age-matched controls were recruited. Results: In quartile analyses, Fe from plants and Fe from white meat intake were inversely associated with breast cancer risk, with OR of 0 center dot 65 (95 % CI 0 center dot 47, 0 center dot 89, P (trend) = 0 center dot 006) and 0 center dot 76 (95 % CI 0 center dot 61, 0 center dot 96, P (trend) = 0 center dot 014), respectively, comparing the highest with the lowest quartile. No associations were observed between total dietary Fe, heme or non-heme Fe, Fe from meat or red meat and breast cancer risk. RCS analysis demonstrated J-shaped associations between total dietary Fe, non-heme Fe and breast cancer, and reverse L-shaped associations between heme Fe, Fe from meat and Fe from red meat and breast cancer. Conclusion: Fe from plants and white meat were inversely associated with breast cancer risk. Significant non-linear J-shaped associations were found between total dietary Fe, non-heme Fe and breast cancer risk, and reverse L-shaped associations were found between heme Fe, Fe from meat or red meat and breast cancer risk.