Effect of a Western-style diet fortified with increased calcium and vitamin D on mammary gland of C57BL/6 mice.
We previously reported hyperproliferation and hyperplasia in C57Bl/6 mouse mammary gland after feeding a Western-style diet (WD); these findings decreased after supplementing WD with increased calcium and vitamin D(3). We now again fortified WD with increased calcium and vitamin D(3) from two sources: (1) a food source, calcium- and vitamin D(3)-enriched yogurt (WD(y) diet) or (2) adding calcium and vitamin D(3) directly to WD (WD(CaD) diet). After 6 months of feeding the number of mammary ducts was higher in mice consuming WD compared to WD(y) (216.0 vs. 202.7, P <.05) and WD(CaD) (216.0 vs. 194.9, P <.001). The percentage of small ducts increased in WD compared to AIN-76A controls (23.3% vs. 17.4%) but was lower in the WD(y) (17.1%) and WD(CaD) (14.8%) groups. WD mice had higher numbers of epithelial cells per duct than WD(y) (33.2 vs. 27.4, P <.001) and WD(CaD) (33.2 vs. 27.8, P <.001) mice, and AIN-76A-fed mice had higher numbers than WD(y) (31.1 vs. 27.4, P <.005) or WD(CaD) (31.1 vs. 27.8, P <.01) mice. Mitotic index was higher in WD than in WD(CaD) mice (0.0020 vs. 0.0009, P <.001). Thus, small mammary gland ductules and mitosis increased after feeding WD and decreased after supplementing the diets with increased calcium and vitamin D(3), administered either in a dairy food (yogurt) or directly as calcium carbonate plus vitamin D(3) in WD, suggesting further study of these nutrients for their possible relationship to breast cancer prevention.
Kurihara
Naoto
N
Strang Cancer Research Laboratory, Department of Medicine (Gastroenterology and Hepatology), Weill Medical College of Cornell University, New York, New York 10021, USA.
Fan
Kunhua
K
Thaler
Howard T
HT
Yang
Kan
K
Lipkin
Martin
M
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000008:administration & dosage*; D002452:Cell Count; D004032:Diet; D004847:Epithelial Cells; D005260:Female; D005527:Food, Fortified / Q000032:analysis*; D008321:Mammary Glands, Animal / Q000166:cytology / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D008938:Mitosis / Q000187:drug effects; D014807:Vitamin D / Q000008:administration & dosage*
D014807:Vitamin D; D002118:Calcium