Article

Dietary Soy Intake and Breast Cancer Risk

Carol A. Enderlin

Elizabeth Ann Coleman

Carol B. Stewart

Reza Hakkak

risk factors, diet
ONF 2009, 36(5), 531-539. DOI: 10.1188/09.ONF.531-539

Purpose/Objectives: To conduct a metasynthesis of the literature on human studies of the relationship between dietary soy intake and breast cancer risk.

Data Sources: Publications in English reporting human studies were searched with the terms soy and breast cancer, using Ovid®, PubMed, and EBSCO databases. Only human studies investigating the relationship of soy intake to breast cancer development in women published from January 1997 through June 2008 were included in the review.

Data Synthesis: A total of 364 publications were located; 18 of the studies met the inclusion criteria and 18 additional studies were located through other publications identified in the search. Because four articles reported on the same two studies, a total of 34 studies were included in the review.

Conclusions: The naturally occurring dietary intake of soy food or its components appears safe for women without breast cancer; however, the safety of high supplements of soy or its components is less certain.

Implications for Nursing: Nurses should become more knowledgeable about soy foods and supplements and include soy intake in dietary assessments. Nurses caring for women at high risk for or with a history of breast cancer should confer with dietitians on current practice recommendations. Women with health issues should avoid initiating high intake of soy dietary supplements until the possible effects are better understood.

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    References

    Adlercreutz, H. (1995). Phytoestrogens: Role in cancer protection. Environmental Health Perspectives, 103(Suppl. 7), 103-112.
    American Cancer Society. (2009). What causes cancer? Retrieved July 24, 2009, from http://www.cancer.org/docroot/CRI/content/CRI_2_2_2X_What_causes_breast_cancer_5.asp?sitearea=
    Barnes, S., Boersma, B., Patel, R., Kirk, M., Darley-Usmar, V.M., Kim, H., et al. (2000). Isoflavonoids and chronic disease: Mechanisms of action. Biofactors, 12(1-4), 209-215.
    Biology Online. (2005). Soy. Retrieved August 26, 2008, from http://www.biology-online.org/dictionary/Soy
    Bosetti, C., Spertini, L., Parpinel, M., Gnagnarella, P., Lagiou, P., Negri, E., et al. (2005). Flavonoids and breast cancer risk in Italy. Cancer Epidemiology Biomarkers and Prevention, 14(4), 805-808.
    Boucher, B.A., Cotterchio, M., Krieger, N., & Thompson, L.U. (2008). Soy formula and breast cancer risk. Epidemiology, 19(1), 165-166
    Cooper, H. (1998). Synthesizing research: A guide for literature reviews. Thousand Oaks, CA: Sage.
    Cui, X., Dai, Q., Tseng, M., Shu, X.O., Gao, Y.T., & Zheng, W. (2007). Dietary patterns and breast cancer risk in the Shanghai breast cancer study. Cancer Epidemiology Biomarkers and Prevention, 16(7), 1443-1448.
    Dai, Q., Shu, X.O., Jin, F., Potter, J.D., Kushi, L.H., Teas, J., et al. (2001). Population-based case-control study of soy food intake and breast cancer risk in Shanghai. British Journal of Cancer, 85(3), 372-378.
    den Tonkelaar, I., Keinan-Boker, L., Veer, P.V., Arts, C.J., Adlercreutz, H., Thijssen, J.H., et al. (2001). Urinary phytoestrogens and post-menopausal breast cancer risk. Cancer Epidemiology Biomarkers and Prevention, 10(3), 223-228.
    Do, M.H., Lee, S.S., Jung, P.J., & Lee, M.H. (2007). Intake of fruits, vegetables, and soy foods in relation to breast cancer risk in Korean women: A case-control study. Nutrition and Cancer, 57(1), 20-27.
    Do, M.H., Lee, S.S., Kim, J.Y., Jung, P.J., & Lee, M.H. (2007). Fruits, vegetables, soy foods, and breast cancer in pre- and postmenopausal Korean women: A case-control study. International Journal of Vitamin and Nutrition Research, 77(2), 130-141.
    Dos Santos Silva, I., Mangtani, P., McCormack, V., Bhakta, D., McMichael, A.J., & Sevak, L. (2004). Phytoestrogen intake and breast cancer risk in South Asian women in England. Cancer Causes and Control, 15(8), 805-818.
    Grace, P.B., Taylor, J.I., Low, Y.L., Luben, R.N., Mulligan, A.A., Botting, N.P., et al. (2004). Phytoestrogen concentrations in serum and spot urine as biomarkers for dietary phytoestrogen intake and their relation to breast cancer risk in a European prospective investigation. Cancer Epidemiology Biomarkers and Prevention, 13(5), 698-708.
    Higdon, J. (2007). An evidence-based approach to dietary phytochemicals. New York: Thieme Medical.
    Hirose, K., Imaeda, N., Tokudome, Y., Goto, C., Wakai, K., Matsuo, K., et al. (2005). Soybean products and reduction of breast cancer risk: A case-control study in Japan. British Journal of Cancer, 93(1), 15-22.
    Hirose, K., Takezaki, T., Hamajima, N., Miura, S., & Tajima, K. (2003). Dietary factors protective against breast cancer in Japanese premenopausal and postmenopausal women. International Journal of Cancer, 107(2), 276-282.
    Horn-Ross, P.L., Hoggatt, K.J., West, D.W., Krone, M.R., Stewart, S.L., Anton, H., et al. (2002). Recent diet and breast cancer risk: The California Teachers Study (USA). Cancer Causes and Control, 13(5), 407-415.
    Horn-Ross, P.L., John, E.M., Lee, M., Stewart, S.L., Koo, J., Sakoda, L.C., et al. (2001). Phytoestrogen consumption and breast cancer risk in a multiethnic population: The Bay Area Breast Cancer Study. American Journal of Epidemiology, 154(5), 434-441.
    Ingram, D., Sanders, K., Kolybaba, M., & Lopez, D. (1997). Case-control study of phytoestrogens. Lancet, 350(9083), 990-994.
    Iwasaki, M., Inoue, M., Otani, T., Sasazuki, S., Kurahashi, N., Miura, T., et al. (2008). Plasma isoflavone level and subsequent risk of breast cancer among Japanese women: A nested case-control study from the Japan Public Health Center-based prospective study group. Journal of Clinical Oncology, 26(10), 1677-1683.
    Keinan-Boker, L., van der Schouw, Y.T., Grobbee, D.E., & Peeters, P.H. (2004). Dietary phytoestrogens and breast cancer risk. American Journal of Clinical Nutrition, 79(2), 282-288.
    Kelly, G.E., Nelson, C., Waring, M.A., Joannou, G.E., & Reeder, A.Y. (1993). Metabolites of dietary (soya) isoflavones in human urine. Clinica Chimoca Acta, 223(1-2), 9-22.
    Key, T.J., Sharp, G.B., Appleby, P.N., Beral, V., Goodman, M.T., Soda, M., et al. (1999). Soya foods and breast cancer risk: A prospective study. British Journal of Cancer, 81(7), 1248-1256.
    Lampe, J., Nishino, Y., Ray, R., Wu, C., Li, W., Lin, M.G., et al. (2007). Breast cancer among women in Shanghai, China. Cancer Epidemiology, Biomarkers and Preventions, 16(12), 2579-2586.
    Lee, M.M., Chang, I.Y., Horng, C.F., Chang, J.S., Cheng, S.H., & Huang, A. (2005). Breast cancer and dietary factors in Taiwanese women. Cancer Causes and Control, 16(8), 929-937.
    Linseisen, J., Piller, R., Hermann, S., & Chang-Claude, J. (2004). Dietary phytoestrogen intake and premenopausal breast cancer risk in a case-control study. International Journal of Cancer, 110(2), 284-290.
    Linus Pauling Institute. (2008). Phytochemicals. Retrieved September 18, 2008, from http://lpi.oregonstate.edu/infocenter/phytochemicals.html
    Medicinenet.com. (2004). Medterms dictionary: Definition of equol. Retrieved October 14, 2008, from http://www.medterms.com/script/main/art.asp?articlekey=32272
    MedlinePlus. (2008). Soy. Retrieved October 23, 2008, from http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-soy.html
    Messina, M. (2008). Soy and health: Isoflavones. Retrieved September 22, 2008, from http://www.soyconnection.com/health_nutrition/pdf/IsofavonesFactSheet.pdf
    Murkies, A., Dalais, F.S., Briganti, E.M., Burger, H.G., Healy, D.L., Wahlqvist, M.L., et al. (2000). Phytoestrogens and breast cancer in postmenopausal women: A case control study. Menopause, 7(5), 289-296.
    National Cancer Institute. (2004). Antioxidants and cancer prevention: Fact sheet. Retrieved November 18, 2008, from http://www.nci.nih.gov/cancertopics/factsheet/antioxidantsprevention
    National Cancer Institute. (2009). SEER stat fact sheets. Retrieved July 24, 2009, from http://seer.cancer.gov/statfacts/html/breast.html
    Nishio, K., Niwa, Y., Toyoshima, H., Tamakoshi, K., Kondo, T., Yatsuya, H., et al. (2007). Consumption of soy foods and the risk of breast cancer: Findings from the Japan Collaborative Cohort (JACC) Study. Cancer Causes and Control, 18(8), 801-808.
    Peeters, P.H., Keinan-Boker, L., van der Schouw, Y.T., & Grobbee, D.E. (2003). Phytoestrogens and breast cancer risk. Breast Cancer Research and Treatment, 77(2), 171-183.
    Peterson, J., Lagiou, P., Samoli, E., Lagiou, A., Katsouyanni, K., La Vecchia, C., et al. (2003). Flavanoid intake and breast cancer risk: A casecontrol study in Greece. British Journal of Cancer, 89(7), 1255-1259.
    Piller, R., Chang-Claude, J., & Linseisen, J. (2006). Plasma enterolactone and genistein and the risk of premenopausal breast cancer. European Journal of Cancer Prevention, 15(3), 225-232.
    Setchell, K.D., Brown, N.M., & Lydeking-Olsen, E. (2002). The clinical importance of the metabolite equol—A clue to the effectiveness of soy and its isoflavones. Journal of Nutrition, 132(12), 3577-3584.
    Shannon, J., Ray, R., Wu, C., Nelson, Z., Gao, D.L., Li, W., et al. (2005). Food and botanical groupings and risk of breast cancer. Cancer Epidemiology Biomarkers and Prevention, 14(1), 81-90.
    Shu, X.O., Jin, F., Dai, Q., Wen, W., Potter, J.D., Kushi, L.H., et al. (2001). Soy food intake during adolescence and subsequent risk of breast cancer among Chinese women. Cancer Epidemiology Biomarkers and Prevention, 10(5), 483-488.
    Stock, W.A. (1994). Systematic coding for research synthesis. In C.H. & L.V. Hedges (Eds.), The handbook of research synthesis (pp. 125-138). New York: Russell Sage Foundation.
    Thanos, J., Cotterchio, M., Boucher, B.A., Kreiger, N., & Thompson, L.U. (2006). Adolescent dietary phytoestrogen intake and breast cancer risk (Canada). Cancer Causes and Control, 17(10), 1253-1261.
    Touillaud, M.S., Thiebaut, A.C., Niravong, M., Boutron-Ruault, M.C., & Clavel-Chapelon, F. (2006). No association between dietary phytoestrogens and risk of premenopausal breast cancer in a French cohort study. Cancer Epidemiology Biomarkers and Prevention, 15(12), 2574-2576.
    Travis, R.C., Allen, N.E., Appleby, P.N., Spencer, E.A., Roddam, A.W., & Key, T.J. (2008). A prospective study of vegetarianism and isoflavone intake in relation to breast cancer risk in British women. International Journal of Cancer, 122(3), 705-710.
    Verheus, M., van Gils, C.H., Keinan-Boker, L., Grace, P.B., Bingham, S.A., & Peeters, P.H. (2007). Plasma phytoestrogens and subsequent breast cancer risk. Journal of Clinical Oncology, 25(6), 648-655.
    Wang, L.Q. (2002). Mammalian phytoestrogens: Enterodiol and enterolactone. Journal of the Chromatography B: Analytical Technologies in the Biomedical Life Sciences, 777(1-2), 289-309.
    Ward, H., Chapelais, G., Kuhnle, G.G., Luben, R., Khaw, K.T., & Bingham, S. (2008). Breast cancer risk in relation to urinary and serum biomarkers of phytoestrogen exposure in the European Prospective into Cancer-Norfolk cohort study. Breast Cancer Research, 10(2), R32.
    Witte, J.S., Ursin, G., Siemiatycki, J., Thompson, W.D., Paganini-Hill, A., & Haile, R.W. (1997). Diet and premenopausal bilateral breast cancer. Breast Cancer Research and Treatment, 42(3), 243-251.
    Wu, A.H., Wan, P., Hankin, J., Tseng, C.C., Yu, M.C., & Pike, M.C. (2002). Adolescent and adult soy intake and risk of breast cancer in Asian Americans. Carcinogenesis, 23(9), 1491-1496.
    Wu, A.H., Yu, M.C., Tseng, C.C., Hankin, J., & Pike, M.C. (2003). Green tea and risk of breast cancer in Asian Americans. International Journal of Cancer, 106(4), 574-579.
    Yamamoto, S., Sobue, T., Kobayashi, M., Sasaki, S., & Tsugane, S. (2003). Soy, isoflavones, and breast cancer risk in Japan. Journal of the National Cancer Institute, 95(12), 906-913.
    Zheng, W., Dai, Q., Custer, L.J., Shu, X.O., Wen, W.Q., Jin, F., et al. (1999). Urinary excretion of isoflavonoids and the risk of breast cancer. Cancer Epidemiology Biomarkers and Prevention, 8(1), 35-40.