Soy Nutrition

Soy & Blood Pressure

Andrea — Wed, 09 May 2012 20:07:56 +0000

Coronary heart disease (CHD) includes a number of risk factors. One of the most important is elevated blood pressure. A recent study presented by researchers from Wake Forest University found that the systolic blood pressure (top number) of people consuming the most soy isoflavones was 5 points (mm Hg) lower than that of people who consumed diets low in isoflavones.¹ The effects were especially pronounced in African Americans. Isoflavones are naturally-occurring plant compounds that are found in especially high amounts in soybeans and traditional soyfoods such as soymilk.

Soyfoods can make important contributions to heart-healthy diets. They provide high-quality protein and, in contrast to more traditional sources of protein in Western diets, they are low in saturated fat, high in polyunsaturated fat, and cholesterol free.^2,3 When soyfoods are substituted for animal products, blood cholesterol levels may be reduced.⁴ In addition, soy protein directly lowers LDL blood cholesterol. This benefit of soy protein was formally recognized by the U.S. Food and Drug Administration in 1999 when it approved a health claim for soyfoods and coronary heart disease.⁵

The results from the Wake Forest study by itself do not allow definitive conclusions to be drawn. However, they are consistent with previously published research. To this point, a recently published statistical analysis that included 27 clinical (human intervention) studies found that on average, soy lowered blood pressure about 2 ½ points.⁶

More research into the effects of soy on blood pressure is needed. Given all the advantages of soyfoods, people concerned about reducing their risk of heart disease may want to consider adding soyfoods to their diets.

^{References

1. Richardson S, Smith C, Burke L, Xia Z, Shikany JM, Steffen L, Rodriguez CJ. Dietary isoflavone intake is associated with lower systolic blood pressure: the Coronary Artery Risk Development in Young Adults (CARDIA) Study (Abstract). Am College Cardiol Annual Meeting. 2012.

2. Hughes GJ, Ryan DJ, Mukherjea R, Schasteen CS. Protein digestibility-corrected amino acid scores (PDCAAS) for soy protein isolates and concentrate: Criteria for evaluation. J Agric Food Chem. 2011; 59: 12707-12.

3. Slavin M, Kenworthy W, Yu LL. Antioxidant properties, phytochemical composition, and antiproliferative activity of Maryland-grown soybeans with colored seed coats. J Agric Food Chem. 2009; 57: 11174-85.

4. Jenkins DJ, Mirrahimi A, Srichaikul K, Berryman CE, Wang L, Carleton A, Abdulnour S, Sievenpiper JL, Kendall CW, et al. Soy protein reduces serum cholesterol by both intrinsic and food displacement mechanisms. J Nutr. 2010; 140: 2302S-2311S.

5. Food labeling: health claims; soy protein and coronary heart disease. Food and Drug Administration, HHS. Final rule. Fed Regist. 1999; 64: 57700-33.

6. Dong JY, Tong X, Wu ZW, Xun PC, He K, Qin LQ. Effect of soya protein on blood pressure: a meta-analysis of randomised controlled trials. Br J Nutr. 2011; 106: 317-26.}

Soy & the American Cancer Society

Andrea — Tue, 28 Feb 2012 22:12:22 +0000

According to the American Cancer Society, soy may reduce the risk of certain cancers: “As with other beans or legumes, soy and foods derived from soy are an excellent source of protein and thus provide a good alternative to meat. Soy contains several phytochemicals, and is a rich source of isoflavone phytochemicals, which have weak estrogenic activity and may protect against hormone-dependent cancers. There is growing evidence from epidemiologic studies that the consumption of traditional soy foods such as tofu may decrease the risk of cancers of the breast, prostate, or endometrium, and there is selected evidence for a risk reduction of some other cancers.”

Link to abstract

^{Kushi LH, Doyle C, McCullough M, et al. (2012) American Cancer Society guidelines on nutrition and physical activity for cancer prevention: Reducing the risk of cancer with healthy food choices and physical activity. CA Cancer J Clin 62:30-67.}

Susan Piergeorge, MS, RD

admin — Tue, 28 Feb 2012 21:49:26 +0000

Susan Piergeorge is the nutrition communications specialist at WhiteWave Foods. Her responsibilities include serving as a nutrition spokesperson; developing and managing scientific communications; supporting strong relationships with policymakers, food industry groups, and health care professionals; and assisting with inquiries regarding nutrition, ingredient and allergen information.

Susan’s background includes nutritional counseling, health promotion, sales, marketing, recipe development and culinary presentations. She has healthcare, pharmaceutical and food industry experience. She received her bachelor’s degree in dietetics and nutrition from Florida International University in Miami, and her master’s in human resource development administration from Barry University, also in Miami. Susan has received numerous awards from the American Cancer Society, American Diabetes Association and American Heart Association for her community outreach.

She is a registered dietitian and has authored a book, Boomer Be Well! Rebel Against Aging Through Food, Nutrition and Lifestyle.

Study suggests soy may lower risk for lung cancer

Andrea — Tue, 22 Nov 2011 20:24:16 +0000

A review of 11 studies found a 23% lower risk of lung cancer in those who consumed a higher amount of soy, such as tofu and soymilk, than those who consumed less soy. The authors cautioned the strongest link was in people who never smoked, women, and in Asian populations, and more studies need to be conducted to fully understand the connection between soy and lung cancer.¹

Link to study

^{1. Yang WS, Va P, Wong MY, et al. Soy intake is associated with lower lung cancer risk: results from a meta-analysis of epidemiologic studies. Am J Clin Nutr. 2011 Nov. 9 [Epub ahead of print]}

Katy Raneri, MS, RD

admin — Wed, 05 Oct 2011 18:41:21 +0000

Katy Raneri is the director of nutrition at WhiteWave Foods. Her responsibilities include establishing an industry-wide center of expertise in health and wellness for the company; developing and implementing the company’s nutrition strategy; creating business-building nutrition opportunities; collaborating with R&D to optimize the nutritional value of products; progressing and managing industry and government partnerships; and overseeing nutrition research, communications and clinical trials.

Katy joined WhiteWave Foods after spending more than 25 years at Kraft Foods. At Kraft she provided leadership to global business partners for the development of nutrition strategies as well as guiding the development of nutrition and health positions and policies. During her career she has led groups in applied nutrition, nutrition strategy and nutrition research, and done basic research, product development and R&D strategy. She has also worked as a clinical dietitian and in private practice. She earned her bachelor’s degree in food and nutrition from the University of Vermont and her masters in human nutrition from New York Medical College. Katy is a registered dietitian and the co-author of a U.S. patent.

Mona Rosene, MS, RD

Andrea — Wed, 05 Oct 2011 16:58:56 +0000

Mona Rosene is the lead nutrition research scientist at WhiteWave Foods. She is responsible for providing nutritional guidance on functional ingredients, product development, and claim substantiation. She also investigates new consumer concepts and trends and serves as the principal contact for clinical studies involving WhiteWave Foods products. Mona represents WhiteWave on the Soy Nutrition Institute (SNI) board, which is dedicated to promoting understanding of the impact of soyfoods and other soybean components on human health.
Throughout her career as a dietitian, Mona has held positions in education and training. She worked with Solgar Vitamin and Herb and is an adjunct professor at Front Range Community College. She is active with the Denver Dietetic Association where she has served as president, and she has also been treasurer of the Colorado Dietetic Association. Mona is an active board member for the International Society of Sports Nutrition and participates in the ADA’s dietetic practice groups, including Sports, Cardiovascular, and Wellness Nutritionists, and Dietitians in Functional Medicine. Mona received her bachelor’s degree in exercise physiology from North Dakota State University, a master’s degree in nutrition from South Dakota State University, and she completed her internship at Oklahoma State University.

Are soyfoods safe for breast cancer survivors to consume?

admin — Tue, 04 Oct 2011 21:24:10 +0000

The use of soyfoods by ER+ (estrogen-receptor positive) breast cancer patients is controversial but recent human evidence is supportive of the safety and even possible benefit of whole soyfoods such as tofu and soymilk made from the whole soybean. ER+ breast cancer patients have a history of breast tumors whose growth is stimulated by the hormone estrogen. Soyfood use by such patients is controversial because soybeans and soyfoods contain isoflavones, naturally-occurring plant chemicals classified as phytoestrogens or plant estrogens. However, isoflavones and estrogen are very different. In fact, isoflavones can have effects opposite to those of estrogen and actually share some characteristics in common with the breast cancer drug tamoxifen.

Over the past several years scientists have examined the effect of soyfoods and isoflavone supplements on indicators or markers of breast cancer risk. The results of these studies show that unlike hormone therapy, neither isoflavones nor soyfoods are harmful.¹ Furthermore, studies conducted in China and the United States, have found that breast cancer patients who regularly consume soy have an improved prognosis, both in terms of recurrence and survival, in comparison to those who consume soy infrequently.^2,3,4

Despite the encouraging results, the existing evidence is not sufficient to provide you with a definitive answer to your question. Having said this, many researchers in the field, after considering the most recent study findings, have now concluded that whole soyfoods can be part of the diet of women with a history of breast cancer.

Featured Expert

Mary Hardy

Dr. Hardy is board certified in internal medicine and a specialist in botanical and integrative medicine; she has actively combined complementary and alternative therapies with traditional Western medicine Full bio >>

^{References

1. Messina MJ, Wood CE. Soy isoflavones, estrogen therapy, and breast cancer risk: analysis and commentary. Nutr J 2008; 3; 7; 17.

2. Guha N et al. Soy isoflavones and risk of cancer recurrence in a cohort of breast cancer survivors: the life after cancer epidemiology study. Breast Cancer Res Treat 2009; 118: 395-405.

3. Shu XO et al. Soyfood intake and breast cancer survival. JAMA 2009; 302(22): 2437-2443.

4. Xiao S et al. Presented at the 102nd Annual Meeting of the American Association for Cancer Research, Orlando, FL, April 2-6, 2011.}

Could avoiding soy impact the thyroid function of a person with Hashimoto’s disease?

admin — Tue, 04 Oct 2011 21:17:35 +0000

As background, Hashimoto’s disease, which is also known as Hashimoto’s thyroiditis, is an autoimmune disease. Antibodies react against proteins in the thyroid gland, causing gradual destruction of the gland itself, and can make the gland unable to produce the thyroid hormones the body needs. However, it is a condition that waxes and wanes spontaneously, making it difficult to say that consuming or avoiding soy plays a decisive role.

The impact of soyfoods in thyroid function has been studied for almost 80 years. Much of the interest in the soy and thyroid connection is because soyfoods contain high amounts of isoflavones, a group of naturally-occurring plant chemicals. Isoflavones are being studied for their health benefits in a wide range of areas. Nevertheless, some types of research suggest isoflavones may adversely affect thyroid function in certain individuals.

Extensive clinical (human) research shows conclusively that in healthy individuals with normal thyroid function, neither soyfoods nor isoflavone supplements impact thyroid function.¹ This research includes studies that have been conducted for as long as three years and involved consumption of large amounts of isoflavones.² It is also clear that in hypothyroid patients taking synthetic thyroid hormone, soyfoods are not contraindicated.

What is less clear, however, is the impact of soyfoods on thyroid function in people with Hashimoto’s disease or subclinical hypothyroidism; the latter refers to people with normal thyroid hormone levels, but who are at risk of developing overt hypothyroidism. This research question has yet to be definitively addressed but it is conceivable that in sensitive individuals, soyfoods could adversely impact the thyroid. If that is the case, then one should take thyroxine several hours after (or before) ingesting soy foods.

Therefore, until more data are available, the best advice for people with Hashimoto’s is to work closely with an endocrinologist. Perhaps small amounts of soy can be gradually added to the diet, especially in the case of normal thyroid function tests while not receiving thyroxine. If a person is receiving thryroxine, the strategy noted above may allow consumption of soy foods. However, until definitive research specifically addresses this condition, it is best to take a cautious approach.

Featured Expert

Alan Rogol

Dr. Alan D. Rogol obtained his undergraduate degree in chemistry from MIT and then went to Duke University where he obtained his MD and PhD (physiology). After training in pediatrics at the Johns Hopkins Hospital Full bio >>

^{References

1. Messina M. Redmon G. effects of soy protein and soybean isoflavones on thyroid function in healthy adults and hypothyroid patients: a review of the relevant literature. Thryoid 2006; 16: 249-58.

2. Bitto A et al. Genistein aglycone does not affect thyroid function: results form a three-year, randomized, double-blind, placebo-controlled trial. J Clin Endocrinol. Metab 2010; 95: 3067-72.}

Is soy infant formula safe?

admin — Tue, 04 Oct 2011 18:06:41 +0000

Soy infant formula has been commercially available since the 1960s. Estimates are that more than 20 million American adults received soy infant formula at some point during their infancy. Current data indicate that about 10 to 15 percent of the dollars spent on infant formula are from the purchase of soy infant formula. This formula has been shown to promote normal growth and development.¹ A recent evaluation by the National Institute of Environmental Health Sciences (NIEHS) and the American Academy of Pediatrics (AAP) support its use. The AAP position is that there is “no conclusive evidence from animal, adult human or infant populations that dietary soy isoflavones may adversely affect human development, reproduction, or endocrine function.”² Soy protein is easily digested and the formula itself is lactose-free and fortified with more than 25 nutrients, including calcium, Vitamin D and essential fatty acids. Most infants allergic to cow’s milk formula will not have difficulty with soy formula; however, recommendations concerning the use of soy infant formula for infants allergic to cow’s milk formula vary around the world. Note that soymilk should not be used as a substitute for soy infant formula.

Featured Expert

Alan Rogol

^{References

1. Badger T et al. The health implications of soy infant formula. Am J Clin Nutr 2009; 89(suppl):1668S–72S.

2. Bhatia J, Greer F, and the Committee on Nutrition. Use of Soy Protein-Based Formulas in Infant Feeding. Pediatrics. 2008; 121:1062-1068.}

What is the relationship between soy intake and prostate cancer?

admin — Thu, 29 Sep 2011 17:55:44 +0000

Cancer of the prostate is the most common cancer among U.S. men and the second most common cause of cancer death.¹ However, prostate incidence and mortality rates vary dramatically throughout the world. This variation is due to lifestyle and environmental factors, rather than genetics. Prostate cancer rates in Asia are very low relative to the West.² Although there may be many factors that are responsible for the low Asian rates, several lines of evidence suggest the consumption of soyfoods is one. For example Asian men who eat about two servings of soyfoods daily are about 30 to 50% less likely to have prostate cancer than Asian men who eat little soy.³

There is also intriguing but still speculative data indicating that soy may be useful for men with prostate cancer. Several studies have found that isoflavones, naturally-occurring chemicals in soybeans, slow the rise in prostate specific antigen (PSA) levels in prostate cancer patients who have been unsuccessfully treated for their disease^4,5,6,7 although not all studies show this to be the case.⁸ PSA is the most common clinical test for the detection of prostate cancer and is a measure by which treatment efficacy can be assessed. In addition, recent research showed that in prostate cancer patients, the main soybean isoflavone, genistein, inhibited the activity of an enzyme found in the prostate that enables cancer cells to spread to other tissues.⁹ Genistein also enhances the ability of radiation^10,11 and chemotherapeutic agents¹² to kill prostate cancer cells in test tubes. Finally, very preliminary, just-published research found that isoflavones reduced the side effects associated with radiation treatment for prostate cancer. These side effects include urinary leakage, cramping, and erectile dysfunction.¹³

Overall, there are encouraging data suggesting that soyfoods can be helpful to prostate cancer patients. However, none of the studies in this area are definitive. Therefore, no conclusions can be made at this time. Nevertheless, because soyfoods are very nutritious, they certainly can be part of an overall healthy diet for all men.

Featured Expert

Mark Messina
Dr. Messina is the co-owner of Nutrition Matters, Inc., a nutrition consulting company, an adjunct associate professor at Loma Linda University, and the Executive Director of the Soy Nutrition Institute. Full bio >>

^{References

1. American Cancer Society. Cancer Facts and Figures 2010. Atlanta, GA, 2010.

2. Pisani P, Bray F, Parkin DM. Estimates of the world-wide prevalence of cancer for 25 sites in the adult population. Int. J. Cancer. 2002, 97, 72-81.

3. Yan L, Spitznagel EL. Soy consumption and prostate cancer risk in men: a revisit of a meta-analysis. Am. J. Clin. Nutr. 2009, 89, 1155-63.

4. Messina M, Kucuk O, Lampe JW. An overview of the health effects of isoflavones with an emphasis on prostate cancer risk and prostate-specific antigen levels. J. AOAC Int. 2006, 89, 1121-34.

5. Pendleton JM, Tan WW, Anai S, Chang M, Hou W, Shiverick KT, Rosser CJ. Phase II Trial of Isoflavone in prostate specific antigen recurrent prostate cancer after previous local therapy. BMC Cancer. 2008, 8, 132.

6. Kwan W, Duncan G, Van Patten C, Liu M, Lim J. A phase II trial of a soy beverage for subjects without clinical disease with rising prostate-specific antigen after radical radiation for prostate cancer. Nutr. Cancer. 2010, 62, 198-207.

7. Ide H, Tokiwa S, Sakamaki K, Nishio K, Isotani S, Muto S, Hama T, Masuda H, Horie S. Combined inhibitory effects of soy isoflavones and curcumin on the production of prostate-specific antigen. Prostate. 2010, 70, 1127-33.

8. Devere White RW, Tsodikov A, Stapp EC, Soares SE, Fujii H, Hackman RM. Effects of a high dose, aglycone-rich soy extract on prostate-specific antigen and serum isoflavone concentrations in men with localized prostate cancer. Nutr. Cancer. 2010, 62, 1036-43.

9. Xu L, Ding Y, Catalona WJ, Yang XJ, Anderson WF, Jovanovic B, Wellman K, Killmer J, Huang X, et al. MEK4 function, genistein treatment, and invasion of human prostate cancer cells. J. Natl. Cancer Inst. 2009, 101, 1141-55.

10. Raffoul JJ, Wang Y, Kucuk O, Forman JD, Sarkar FH, Hillman GG. Genistein inhibits radiation-induced activation of NF-kappaB in prostate cancer cells promoting apoptosis and G2/M cell cycle arrest. BMC Cancer. 2006, 6, 107.

11. Raffoul JJ, Banerjee S, Che M, Knoll ZE, Doerge DR, Abrams J, Kucuk O, Sarkar FH, Hillman GG. Soy isoflavones enhance radiotherapy in a metastatic prostate cancer model. Int. J. Cancer. 2007, 120, 2491-8.

12. Li Y, Ahmed F, Ali S, Philip PA, Kucuk O, Sarkar FH. Inactivation of Nuclear Factor {kappa}B by Soy Isoflavone Genistein Contributes to Increased Apoptosis Induced by Chemotherapeutic Agents in Human Cancer Cells. Cancer Res. 2005, 65, 6934-42.

13. Ahmad IU, Forman JD, Sarkar FH, Hillman GG, Heath E, Vaishampayan U, Cher ML, Andic F, Rossi PJ, et al. Soy isoflavones in conjunction with radiation therapy in patients with prostate cancer. Nutr. Cancer. 2010, 62, 996-1000.}