Effect of a Western-Style Diet Fortified with Increased Calcium and Vitamin D on Mammary Gland of C57Bl/6 Mice

• Published in: Journal of medicinal food Vol. 11; no. 2; pp. 201 - 206
• Main Authors: Kurihara, N, Fan, K, Thaler, H.T, Yang, K, Lipkin, M
• Format: Journal Article
• Language: English
• Published: United States 01.06.2008
• Subjects: animal models; Animals; Apoptosis - drug effects; breast neoplasms; calcium; Calcium - administration & dosage; Cell Count; cell proliferation; cholecalciferol; Diet; dietary minerals; Epithelial Cells; Female; Food, Fortified - analysis; fortified foods; mammary ducts; mammary glands; Mammary Glands, Animal - cytology; Mammary Glands, Animal - drug effects; Mice; Mice, Inbred C57BL; mitosis; Mitosis - drug effects; Vitamin D - administration & dosage; vitamin-mineral supplements; yogurt
• ISSN: 1096-620X; 1557-7600
• DOI: 10.1089/jmf.2007.619

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.