June 6, 2009
You may have seen some recent media coverage about soy, and we feel it’s very important to provide facts to clarify and correct any misconceptions. The overwhelming volume of human-based scientific research suggests soyfoods are safe and healthy for men, women, and children. In fact, soyfoods are clinically proven to help maintain healthy cholesterol levels as part of a well-balanced diet. For centuries, millions of people worldwide have consumed soyfoods as a staple to provide high-quality, complete protein, fiber, polyunsaturated oils, key vitamins and minerals.
When reviewing articles about soy or any food, it is important to examine critically the research findings. One must ask how many subjects were involved, how much of the substance was consumed, under what conditions did it take place, and what other factors might have influenced the outcome. Often, the intake of medications or dietary supplements, diseases such as diabetes, heart disease, and mental health, being overweight, and other lifestyle factors have been found to be directly connected to reproductive health and other health problems.
As for soy, one of the greatest benefits is that soy protein has been consistently shown to lower blood cholesterol. In 1999, FDA approved a health claim for soy protein that states, “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”. Since 1999, a substantial amount of additional research continues to support the role of soy protein as part of a heart healthy diet. (1, 2, 3, 4)
In addition, soy research has begun to show benefits of soy in preventing prostate cancer.(10) These and other studies of men consuming soy, even at large doses, do not show any relationship between soy intake and negative reproductive health outcomes, such as erectile function, testosterone, reproductive hormones, sperm motility, or sperm quality. (5, 6, 7, 8, 9)
For further questions, please contacts us at 202-659-3520.
The Soyfoods Association of North America is a non-profit trade association that has been promoting consumption of soyfoods in the diet since 1978. SANA is committed to encouraging sustainability, integrity and growth in the soyfoods industry by promoting the benefits and consumption of soy-based foods and ingredients in diets. More information is available at www.soyfoods.org.
1. McDonald A. “Effects of Soy Protein on T0tal Cholesterol and LDL-Cholesterol: Review of Published Studies 1998-2008.” Radiant Development., May, 23, 2008. Submitted to FDA in response to the review of the soy protein health claim, FDA Docket No. 2007N–0464 on June 18, 2008.
2. Anderson J. “Soy Protein Effects on Serum Lipoproteins: A Quality Assessment and Weighted Analysis of Randomized, Controlled Studies.” Submitted to FDA in response to the review of the soy protein health claim, FDA Docket No. 2007N–0464 on June 18, 2008.
3. Solae LLC. “Evidence-Based Review In Support of The Soy Protein & Coronary Heart Disease Health Claim.” Submitted to FDA in response to the review of the soy protein health claim, FDA Docket No. 2007N–0464, June 5, 2008.
4. Harland JI and Haffner TA. “Does 25g soya protein reduce blood cholesterol: a systematic review and meta analysis”.
5. Allen NE, Appleby PN, Davey GK, Key TJ. Soy Milk Intake in Relation to Serum Sex Hormone Levels in British Men. Nutrition and Cancer, 41(1&2), 2001. 41–46.
6. Mendiola J, Torres-Cantero AM, Moreno-Grau JM, Ten J, Roca M, Moreno-Grau S, Bernabeu R. Food intake and its relationship with semen quality: a case-control study. Fertil Steril. 2009 Mar;91(3):812-8. Epub 2008 Mar
7. Kurzer M. Hormonal Effects of Soy in Premenopausal Women and Men. J. Nutr. 132: 570S–573S, 2002
8. Effect of protein source and resistance training on body composition and sex hormones. Kalman D, Feldman S, Martinez M, Krieger DR, Tallon MJ. J Int Soc Sports Nutr. 2007 Jul 23;4:4
9. Serum prostate-specific antigen but not testosterone levels decrease in a randomized soy intervention among men. Maskarinec G, Morimoto Y, Hebshi S, Sharma S, Franke AA, Stanczyk FZ. Eur J Clin Nutr. 2006 Dec;60(12):1423-9. Epub 2006 Jun 14.
10. Lin 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.