1. Soy: Healthy or Harmful Presented by Megan Hetherington-Rauth, RD

2. Abundance of Soy Thirty-seven percent of Americans consume soyfoods or soy beverages once a month or more One of the biggest national crops in US Used in foods, candles, soaps, cosmetics, clothing, plastics, insulation...etc.

3. The Soybean Part of the legume family Good source of protein Contains essential fatty acids (Omega-6, Omega-3) Unique dietary source of isoflavones -weak phytoestrogens (estrogen-like compounds found in plants).

4. Types of soy products Fermented - Tempeh, Miso, Natto, Tamari, soybean paste, soy sauce Unfermented - edamame, soy milk, tofu, soybean oil, soy cheeses, soy ice cream, soy infant formula, soy protein

5. Benefits of Soy Coronary Heart Disease – 1999 FDA health claim for soy “25 grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.” -soy protein lowers LDL cholesterol (“bad” cholesterol) *some studies have shown -isoflavones in soy imporve endothelial function -soy proteins/soy foods lower blood pressure

6. Breast Cancer and Soy High estrogen levels and exposure of breast tissues to estrogen can lead to breast tumor growth Soy high in isoflavones which are chemically similar to estrogen Speculation that consumption of soy causes breast cancer

7. Breast cancer and soy Contrary to what is thought isoflavones may actually reduce breast cancer risk - isoflavones in soy block more potent natural estrogens from binding to estrogen receptor -stop formation of estrogen in fat tissue -stimulate production of protein that binds estrogen in blood so it can’t bind to estrogen receptor -anti-oxidant and anti-inflammatory properties

8. Breast Cancer and soy The 2012 American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Survivors concluded that current research finds no harmful effects to breast cancer survivors from eating soy. -cancer survivors who consumed >10mg isoflavones/d had reduced risk of reoccurance Nechuta SJ, et al.

9. Prostate Cancer and soy consumption of soy foods is associated with a reduction in prostate cancer risk in men Yan L. and Spitznagel L. Isoflavones may inhibit prostate tumor spread

10. Soy and Hormonal Effects in Men Through examination of all the clinical evidence, feminization concerns are unwarrented Messina M. -no significant effects of exposure to soy on reproductive hormones or sperm counts

11. Soy and Thyroid Function Isoflavones do not adversly affect thyroid function Messina M. And Redmond G. Soy and Cognitive Function Mixed finding in studies

12. Soy and Osteoporosis Osteoporosis: disease of the bones in which bone mineral density (BMD) is reduced which leads to an increased risk of fractures Estrogen is a hormone that strongly determines rate of bone breakdown

13. Soy and Osteoporosis cont. Isoflavones (act like estrogen) may have possible skeletal benefits >25 trials have been done on effect of isoflavone from soy on BMD -several show skeletal benefits -more studies need to be done in order to come to any conclusion

14. Soy and Menopause Symptoms During menopause, drop in estrogen levels can trigger hot flashes Estrogen like effects of isoflavones might mitigate this drop >50 studies published – Most results were supportive of isoflavones – No definite conclusions can be made yet

15. The equol hypothesis SoybeansIsoflavonesDaidzin Intestinal bacterial transformation Equol Not all people have the types of bacteria present to produce equol -50% of Asians can -20-30% of North Americans and Europeans can Suggested that maximal health benefits to soy protein seen in equol producers An area for future research

17. Conclusion With exception of those who are allergic, there is little evidence that soyfoods are contraindicated for any individual Good guide to achieve the proposed health benefits of soyfoods is 2 servings/d (~15-20g protein, 50-75 mg isoflavones)

18. References Messina M, Watanabe S, Setchell K. Report on the 8 th International Symposium on the Role of Soy in Health Promotion and Chronic Disease Prevention and Treatment. J Nutr. 2009; 139: (4) 796S-802S. Messina M, Wu AH. Perspectives on the soy-breast cancer relation. Am J Clin Nutr. 2009; 89(5): 1673S-1679S. Mark Messina. Insights Gained from 20 Years of Soy Research. J. Nutr. 2010; 140(12): 2289S-2295S Koh E. Mithell AE. Urinary isoflavone excretion in Korean adults: comparison of soybean paste and unfermented soy flour. J. Sci. Food Agric., 87: 2112–2120. Densie Webb. July 1, 2009. Savor: Soybeans. Food and Nutr. http://foodandnutritionmag.org/savor-soybeans. http://foodandnutritionmag.org/savor-soybeans Doheny K. July 1, 2011. Benefits of Soy: A Mixed Bag. http://www.webmd.com/food- recipes/news/20110630/benefits-of-soy-a-mixed-bag.http://www.webmd.com/food- recipes/news/20110630/benefits-of-soy-a-mixed-bag

19. August 23, 2012. Soy: Healthy or Harmful. Huffingtonpost Healthy Living. http://www.huffingtonpost.com/2012/08/23/soy- healthy_n_1823052.html?view=print&comm_ref=false. http://www.huffingtonpost.com/2012/08/23/soy- healthy_n_1823052.html?view=print&comm_ref=false Bergman R, Pavese J. Soy Isoflavones may reduce prostate cancer risk. The Soy Connection.2012; 20(4):1-4. http://www.soyconnection.com/upload/Soy_Health_and_Nutrition_Newsletter_Fall_12_.pdf.http://www.soyconnection.com/upload/Soy_Health_and_Nutrition_Newsletter_Fall_12_.pdf Hwang H, Konhilas JP. Phytoestrogens and the Role in Cardiovascular Health: To Consume or not to consume?. Bioactive Foods as Dietary Interventions for Cardiovascular Disease (ch 18). http://books.google.com/books?hl=en&lr=&id=MmmbtNMw7HQC&oi=fnd&pg=PA283&dq=soy+and+h ealth&ots=_IwxrhGngJ&sig=-x-0E-9hQESy_PX- D_XCHE9yEYA#v=onepage&q=soy%20and%20health&f=false. http://books.google.com/books?hl=en&lr=&id=MmmbtNMw7HQC&oi=fnd&pg=PA283&dq=soy+and+h ealth&ots=_IwxrhGngJ&sig=-x-0E-9hQESy_PX- D_XCHE9yEYA#v=onepage&q=soy%20and%20health&f=false Terrain MV. The Dark Side of Soy. Utne Reader. July/August 2007. http://www.utne.com/2007-07- 01/Science-Technology/The-Dark-Side-of-Soy.aspx.http://www.utne.com/2007-07- 01/Science-Technology/The-Dark-Side-of-Soy.aspx Larkin T, Price W, Asthelmer L. The Key Importance of Soy Isoflavone bioavailabilty to understanding health benefits. Cr Rev in Food Sci and Nutr. 2008; 48(6). McCullough M. August 2, 2012. The Bottom Line on Soy and Breast Cancer Risk. American Cancer Society. http://www.cancer.org/cancer/news/expertvoices/post/2012/08/02/the-bottom-line-on-soy- and-breast-cancer-risk.aspx.http://www.cancer.org/cancer/news/expertvoices/post/2012/08/02/the-bottom-line-on-soy- and-breast-cancer-risk.aspx

20. Health Claims Meeting Significant Scientific Agreement. U.S. Food and Drug Administration. http://www.fda.gov/food/labelingnutrition/labelclaims/healthclaimsmeetingsignificantscientificagreem entssa/default.htm. http://www.fda.gov/food/labelingnutrition/labelclaims/healthclaimsmeetingsignificantscientificagreem entssa/default.htm María Elena Martínez, Cynthia A. Thomson, and Stephanie A. Smith-Warner. Soy and Breast Cancer: The Controversy Continues. J Natl Cancer Inst. 2006; 98(7): 430-431. http://jnci.oxfordjournals.org/citmgr?gca=jnci;98/7/430. http://jnci.oxfordjournals.org/citmgr?gca=jnci;98/7/430 Soy. Memorial Sloan-Kettering Cancer Center. http://www.mskcc.org/cancer-care/herb/soy.http://www.mskcc.org/cancer-care/herb/soy Messina M, Redmond G. Effects of soy protein and soybean isoflavones on thyroid function in healthy adults and hypothyroid patients: a review of the relevant literature. Thyroid. 2006; 16(3): 249-258. Zhao L, Brinton RD. WHI and WHIMS follow-up and human studies of soy isoflavones on cognition. Exper Rev. Neurother. 2007; 7(11): 1549-64. Cornwell T, Cohick W. Raskin I. Dietary phytoestrogens and health. Phytochemistry. 2004; 65: 995-1016. http://www.biology.uoc.gr/courses/BIO316_Moriaki_Fisiologia/PDF/%CE%A0%CE%91%CE%A1%CE%9F %CE%A5%CE%A3%CE%99%CE%91%CE%A3%CE%95%CE%99%CE%A3/Dietary%20phytoestrogens%20an d%20health.pdf. http://www.biology.uoc.gr/courses/BIO316_Moriaki_Fisiologia/PDF/%CE%A0%CE%91%CE%A1%CE%9F %CE%A5%CE%A3%CE%99%CE%91%CE%A3%CE%95%CE%99%CE%A3/Dietary%20phytoestrogens%20an d%20health.pdf Nechuta S, et al. Soy food intake after diagnosis of breast cancer and survival. Am J Clin Nutr. 2012; 96:123-32. Atkinson C, et al. Gut Bacterial Metabolism of the Soy Isoflavone Daidzein: Exploring the Relevance to Human Health. Exp Bio Med. 2005; 230(3): 155-170. Sales and Trends. Soyfoods Association of North America. http://www.soyfoods.org/soy- information/sales-and-trends.http://www.soyfoods.org/soy- information/sales-and-trends