The Association Between Dietary Calcium Intake and Breast Cancer Risk Among Iranian Women Publisher Pubmed



Ebrahimpourkoujan S¹ ; Benisikohansal S² ; Azadbakht L^{2, 3} ; Esmaillzadeh A^{2, 4, 5}
Source: Nutrition and Cancer Published:2022

Abstract

Background: No information is available from Middle Eastern countries linking dietary calcium intake and odds of breast cancer. Objective: This study was conducted to investigate the association between dietary calcium intake and odds of having breast cancer among Iranian women. Methods: In this population-based case-control study, 350 newly diagnosed breast cancer cases were recruited and 700 age-matched subjects were enrolled as controls. Dietary intakes were examined by the use of a 106-item validated FFQ. Total dietary calcium intake of each participant was computed by summing up calcium intake from all foods and dishes. The quartile cutoff points of energy-adjusted calcium intake was obtained in the control group. These cutoff points were used to classify all study participants into quartiles in terms of dietary calcium intake. Results: After adjustment for age and energy intake, we found that individuals in second quartile of calcium intake were 43% less likely to have breast cancer compared with those in the bottom quartile (OR: 0.57; 95% CI: 0.38–0.86). This significant association disappeared after further controlling for other potential confounders including dietary factors and BMI (OR: 0.91; 95% CI: 0.57–1.45). When the analyses were done by menopausal status, premenopausal women with the greatest calcium intake were 60% less likely to have breast malignancy than those with the lowest intake (OR: 0.40; 95% CI: 0.16–0.99). Adjustment for potential confounders did not substantially influence this finding (OR: 0.32; 95% CI: 0.11–0.95). The association remained significant even after additional controlling for dietary covariates (OR: 021; 95% CI: 0.06–0.72) and BMI (OR: 0.21; 95% CI: 0.04–0.93). No significant association was found between dietary calcium intakes and odds of breast cancer in postmenopausal women. Discussion: Dietary calcium intake was protectively associated with odds of breast cancer in premenopausal women, but not in postmenopausal women. Further prospective investigations are needed to confirm these findings. © 2021 Taylor & Francis Group, LLC.