Soy - Research:
Studies suggest that soy may reduce coronary heart disease risk.3,4 Research suggests that it may also improve bone health by increasing bone density and reducing bone loss.5,6,7,8 Soy protein can lower cholesterol9 and, in 1999, the US Food and Drug Administration (FDA) approved a health claim for the cardiovascular benefits of foods containing at least 6.25 grams of soy protein with limited fat and salt content.10 In a review of 19 clinical trials testing the usefulness of soy for relieving menopausal symptoms, the authors report that soy is modestly effective for women experiencing five or more hot flashes per day.11
Soy protein is one of the few sources of protein that is vegetable based. Unlike animal protein, soy protein is comparatively low in cholesterol and fat. Soy protein has been used in both food and industrial products, such as baby food, breakfast cereals, meat substitutes, cleaning compounds, plastics, textiles, and cosmetics.2
2 Soy Protein Council. Protein Quality and Human Nutrition, 1986. Available at: http://www.spcouncil.org/SoyProtein.pdf. Accessed December 3, 2004.
3 Squadrito F, Altavilla D, Morabito N, Crisafulli A, D’Anna R, Corrado F, et al. The effect of the phytoestrogen genistein on plasma nitric oxide concentrations, endothelin-1 levels and endothelium dependent vasodilation in in postmenopausal women. Atherosclerosis. 2002;163:339-347.
4 Nestel PJ, Yamashita T, Sasahara T, Pomeroy S, Dart A, Komesaroff P, et al. Soy isoflavones improve systemic artherial compliance but not plasma lipids in menopausal and perimenopausal women. Arteroscler Thromb Vasc Biol. 1997;17:3392-3398.
5 Arjmandi BH. The role of phytoestrogens in the prevention and treatment of osteoporosis in ovarian hormone deficiency. J Am Coll Nutr. 2001;20:398S-402S.
6 Alekel DL, Germain AS, Peterson CT, Hanson KB, Stewart JW, Toda T. Isoflavone-rich soy protein isolate attenuates bone loss in the lumbar spine of perimenopausal women. Am J Clin Nutr. 2000;72:844-852.
7 Morabito N Crisafulli A, Vergara C, Gaudio A, Lasco A, Frisina N, et al. Effects of genistein and hormone-replacement therapy on bone loss in early postmenopausal women: a randomized double-blind placebo-controlled study. J Bone Miner Res. 2002;17:1904-1912.
8 Potter SM, Baum JA, Teng H, Stillman RJ, Shay NF, Erdman JW Jr. Soy protein and isoflavones: their effects on blood lipids and bone density in postmenopausal women. Am J Clin Nutr. 1998;68:1375S-1379S.
9 Anderson JW, Johnstone BM, Cook-Newell ME. Meta-analysis of the effects of soy protein intake on serum lipids. N Engl J Med. 1995:333:276-282.
10 FDA Talk Paper. FDA Approves New Health Claim for Soy Protein and Coronary Heart Disease. Available at: http://www.cfsan.fda.gov/~lrd/tpsoypr2.html. Accessed May 6, 2005.
11 Messina M, Hughes C. Efficacy of soyfoods and soybean isoflavone supplements for alleviating menopausal symptoms is positively related to initial hot flush frequency. J Med Food. 2003;6:1-11.