This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hakkak, R. Articles by Badger, T. M. Search for Related Content PubMed PubMed Citation Articles by Hakkak, R. Articles by Badger, T. M.

Diets Containing Whey Proteins or Soy Protein Isolate Protect against 7,12-Dimethylbenz(a)anthracene-induced Mammary Tumors in Female Rats¹

Arkansas Children’s Nutrition Center and Departments of Pediatrics [R. H., S. R. S., S. L., M. J. J. R., T. M. B.] and Pathology [S. K.], University of Arkansas for Medical Sciences, Little Rock, Arkansas 72202

A study was conducted to determine the protective effects of two common dietary proteins, soy protein isolate (soy) and bovine whey, against chemically induced mammary tumors in female Sprague Dawley rats. Rats were fed AIN-93G diets having casein, soy, or whey as the sole protein source. Rats within the same dietary groups were mated to obtain the F₁ and F₂ generations. At age 50 days, F₁ (experiment A) or F₂ (experiment B) female offspring (19 rats/group) were p.o. gavaged with 80 mg/kg 7,12-dimethylbenz(a)anthracene, and mammary glands were evaluated when 100% of the casein-fed group developed at least one palpatable tumor. Rats grew well on all three diets, but casein-fed rats gained slightly more body weight than soy- or whey-fed rats (P < 0.05). Vaginal opening occurred 1 day earlier in soy-fed rats than in casein- or whey-fed rats, but no other differences in reproductive and developmental parameters were observed between groups. When 50% of the casein-fed rats had at least one mammary tumor, lower tumor incidences (24–34%) were observed in the soy-fed (P < 0.009) and whey-fed groups (P < 0.001). When 100% of the casein-fed rats had at least one tumor, soy-fed rats had a lower tumor incidence (77%) in experiment B (P < 0.002), but not in experiment A (P < 0.12), and there were no differences in tumor multiplicity. Whey-fed rats had lower mammary tumor incidence (54–62%; P < 0.002) and multiplicity (P < 0.007) than casein-fed rats in both experiments. Our results indicate that diets rich in soy reduce the incidence of chemically induced mammary tumors by approximately 20%. Furthermore, whey appears to be at least twice as effective as soy in reducing both tumor incidence and multiplicity.

This article has been cited by other articles:

				Y. Su, F. A. Simmen, R. Xiao, and R. C. M. Simmen Expression profiling of rat mammary epithelial cells reveals candidate signaling pathways in dietary protection from mammary tumors Physiol Genomics, June 19, 2007; 30(1): 8 - 16. [Abstract] [Full Text] [PDF]

				Y. Su, R. R. Eason, Y. Geng, S. Till, T. M. Badger, and R. C.M. Simmen In utero exposure to maternal diets containing soy protein isolate, but not genistein alone, protects young adult rat offspring from NMU-induced mammary tumorigenesis Carcinogenesis, May 1, 2007; 28(5): 1046 - 1051. [Abstract] [Full Text] [PDF]

				R. Singhal, T. M. Badger, and M. J. Ronis Reduction in 7,12-Dimethylbenz[a]anthracene-Induced Hepatic Cytochrome-P450 1A1 Expression Following Soy Consumption in Female Rats Is Mediated by Degradation of the Aryl Hydrocarbon Receptor J. Nutr., January 1, 2007; 137(1): 19 - 24. [Abstract] [Full Text] [PDF]

				S. Cooper, J. R. Latendresse, D. R. Doerge, N. C. Twaddle, X. Fu, and K. B. Delclos Dietary Modulation of p-Nonylphenol-Induced Polycystic Kidneys in Male Sprague-Dawley Rats Toxicol. Sci., June 1, 2006; 91(2): 631 - 642. [Abstract] [Full Text] [PDF]

				P. W. Parodi Dairy Product Consumption and the Risk of Breast Cancer J. Am. Coll. Nutr., December 1, 2005; 24(suppl_6): 556S - 568S. [Abstract] [Full Text] [PDF]

				B. Dave, R. R. Eason, S.R. Till, Y. Geng, M. C. Velarde, T. M. Badger, and R. C.M. Simmen The soy isoflavone genistein promotes apoptosis in mammary epithelial cells by inducing the tumor suppressor PTEN Carcinogenesis, October 1, 2005; 26(10): 1793 - 1803. [Abstract] [Full Text] [PDF]

				T. M. Badger, M. J. J. Ronis, R. C. M. Simmen, and F. A. Simmen Soy Protein Isolate and Protection Against Cancer J. Am. Coll. Nutr., April 1, 2005; 24(2): 146S - 149S. [Abstract] [Full Text] [PDF]

				R. R. Eason, M. C. Velarde, L. Chatman Jr, S. R. Till, Y. Geng, M. Ferguson, T. M. Badger, and R. C. M. Simmen Dietary Exposure to Whey Proteins Alters Rat Mammary Gland Proliferation, Apoptosis, and Gene Expression during Postnatal Development J. Nutr., December 1, 2004; 134(12): 3370 - 3377. [Abstract] [Full Text] [PDF]

				C. D. Allred, K. F. Allred, Y. H. Ju, T. S. Goeppinger, D. R. Doerge, and W. G. Helferich Soy processing influences growth of estrogen-dependent breast cancer tumors Carcinogenesis, September 1, 2004; 25(9): 1649 - 1657. [Abstract] [Full Text] [PDF]

				D. P. Belobrajdic, G. H. McIntosh, and J. A. Owens A High-Whey-Protein Diet Reduces Body Weight Gain and Alters Insulin Sensitivity Relative to Red Meat in Wistar Rats J. Nutr., June 1, 2004; 134(6): 1454 - 1458. [Abstract] [Full Text] [PDF]

				D. Li, G. L. Graef, J. A. Yee, and L. Yan Dietary Supplementation with High-Selenium Soy Protein Reduces Pulmonary Metastasis of Melanoma Cells in Mice J. Nutr., June 1, 2004; 134(6): 1536 - 1540. [Abstract] [Full Text] [PDF]

				J. C. Rowlands, R. Hakkak, M. J. J. Ronis, and T. M. Badger Altered Mammary Gland Differentiation and Progesterone Receptor Expression in Rats Fed Soy and Whey Proteins Toxicol. Sci., November 1, 2002; 70(1): 40 - 45. [Abstract] [Full Text] [PDF]

				T. M. Badger, M. J. J. Ronis, R. Hakkak, J. C. Rowlands, and S. Korourian The Health Consequences of Early Soy Consumption J. Nutr., March 1, 2002; 132(3): 559S - 565. [Abstract] [Full Text] [PDF]

				M. J. Messina and C. L. Loprinzi Soy for Breast Cancer Survivors: A Critical Review of the Literature J. Nutr., November 1, 2001; 131(11): 3095S - 3108. [Abstract] [Full Text] [PDF]

				R. Hakkak, S. Korourian, M. J. J. Ronis, J. M. Johnston, and T. M. Badger Dietary Whey Protein Protects against Azoxymethane-induced Colon Tumors in Male Rats Cancer Epidemiol. Biomarkers Prev., May 1, 2001; 10(5): 555 - 558. [Abstract] [Full Text]

				M. J. Ronis, J. C. Rowlands, R. Hakkak, and T. M. Badger Inducibility of Hepatic CYP1A Enzymes by 3-Methylcholanthrene and Isosafrole Differs in Male Rats Fed Diets Containing Casein, Soy Protein Isolate or Whey from Conception to Adulthood J. Nutr., April 1, 2001; 131(4): 1180 - 1188. [Abstract] [Full Text]