TY - JOUR
T1 - Dairy foods, calcium, and risk of breast cancer overall and for subtypes defined by estrogen receptor status
T2 - a pooled analysis of 21 cohort studies
AU - Wu, You
AU - Huang, Ruyi
AU - Wang, Molin
AU - Bernstein, Leslie
AU - Bethea, Traci N.
AU - Chen, Chu
AU - Chen, Yu
AU - Eliassen, A. Heather
AU - Freedman, Neal D.
AU - Gaudet, Mia M.
AU - Gierach, Gretchen L.
AU - Giles, Graham G.
AU - Krogh, Vittorio
AU - Larsson, Susanna C.
AU - Liao, Linda M.
AU - Mccullough, Marjorie L.
AU - Miller, Anthony B.
AU - Milne, Roger L.
AU - Monroe, Kristine R.
AU - Neuhouser, Marian L.
AU - Palmer, Julie R.
AU - Prizment, Anna
AU - Reynolds, Peggy
AU - Robien, Kim
AU - Rohan, Thomas E.
AU - Sandin, Sven
AU - Sawada, Norie
AU - Sieri, Sabina
AU - Sinha, Rashmi
AU - Stolzenberg-Solomon, Rachael Z.
AU - Tsugane, Shoichiro
AU - Van Den Brandt, Piet A.
AU - Visvanathan, Kala
AU - Weiderpass, Elisabete
AU - Wilkens, Lynne R.
AU - Willett, Walter C.
AU - Wolk, Alicja
AU - Zeleniuch-Jacquotte, Anne
AU - Ziegler, Regina G.
AU - Smith-Warner, Stephanie A.
N1 - Publisher Copyright:
© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.
PY - 2021/8/1
Y1 - 2021/8/1
N2 - Background: Epidemiologic studies examining the relations between dairy product and calcium intakes and breast cancer have been inconclusive, especially for tumor subtypes. Objective: To evaluate the associations between intakes of specific dairy products and calcium and risk of breast cancer overall and for subtypes defined by estrogen receptor (ER) status. Method: We pooled the individual-level data of over 1 million women who were followed for a maximum of 8-20 years across studies. Associations were evaluated for dairy product and calcium intakes and risk of incident invasive breast cancer overall (n = 37,861 cases) and by subtypes defined by ER status. Study-specific multivariable hazard ratios (HRs) were estimated and then combined using random-effects models. Results: Overall, no clear association was observed between the consumption of specific dairy foods, dietary (from foods only) calcium, and total (from foods and supplements) calcium, and risk of overall breast cancer. Although each dairy product showed a null or very weak inverse association with risk of overall breast cancer (P, test for trend >0.05 for all), differences by ER status were suggested for yogurt and cottage/ricotta cheese with associations observed for ER-negative tumors only (pooled HR = 0.90, 95% CI: 0.83, 0.98 comparing ≥60 g/d with <1 g/d of yogurt and 0.85, 95% CI: 0.76, 0.95 comparing ≥25 g/d with <1 g/d of cottage/ricotta cheese). Dietary calcium intake was only weakly associated with breast cancer risk (pooled HR = 0.98, 95% CI: 0.97, 0.99 per 350 mg/d). Conclusion: Our study shows that adult dairy or calcium consumption is unlikely to associate with a higher risk of breast cancer and that higher yogurt and cottage/ricotta cheese intakes were inversely associated with the risk of ER-negative breast cancer, a less hormonally dependent subtype with poor prognosis. Future studies on fermented dairy products, earlier life exposures, ER-negative breast cancer, and different racial/ethnic populations may further elucidate the relation.
AB - Background: Epidemiologic studies examining the relations between dairy product and calcium intakes and breast cancer have been inconclusive, especially for tumor subtypes. Objective: To evaluate the associations between intakes of specific dairy products and calcium and risk of breast cancer overall and for subtypes defined by estrogen receptor (ER) status. Method: We pooled the individual-level data of over 1 million women who were followed for a maximum of 8-20 years across studies. Associations were evaluated for dairy product and calcium intakes and risk of incident invasive breast cancer overall (n = 37,861 cases) and by subtypes defined by ER status. Study-specific multivariable hazard ratios (HRs) were estimated and then combined using random-effects models. Results: Overall, no clear association was observed between the consumption of specific dairy foods, dietary (from foods only) calcium, and total (from foods and supplements) calcium, and risk of overall breast cancer. Although each dairy product showed a null or very weak inverse association with risk of overall breast cancer (P, test for trend >0.05 for all), differences by ER status were suggested for yogurt and cottage/ricotta cheese with associations observed for ER-negative tumors only (pooled HR = 0.90, 95% CI: 0.83, 0.98 comparing ≥60 g/d with <1 g/d of yogurt and 0.85, 95% CI: 0.76, 0.95 comparing ≥25 g/d with <1 g/d of cottage/ricotta cheese). Dietary calcium intake was only weakly associated with breast cancer risk (pooled HR = 0.98, 95% CI: 0.97, 0.99 per 350 mg/d). Conclusion: Our study shows that adult dairy or calcium consumption is unlikely to associate with a higher risk of breast cancer and that higher yogurt and cottage/ricotta cheese intakes were inversely associated with the risk of ER-negative breast cancer, a less hormonally dependent subtype with poor prognosis. Future studies on fermented dairy products, earlier life exposures, ER-negative breast cancer, and different racial/ethnic populations may further elucidate the relation.
KW - breast cancer
KW - calcium
KW - cheese
KW - dairy products
KW - diet
KW - milk
KW - pooled analysis
KW - yogurt
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U2 - 10.1093/ajcn/nqab097
DO - 10.1093/ajcn/nqab097
M3 - Article
C2 - 33964859
AN - SCOPUS:85112306790
SN - 0002-9165
VL - 114
SP - 450
EP - 461
JO - American Journal of Clinical Nutrition
JF - American Journal of Clinical Nutrition
IS - 2
ER -
