![]() |
|
|
Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108
2To whom correspondence should be addressed. E-mail: mkurzer{at}umn.edu
Over the past few years, there has been increasing interest in the possible hormonal effects of soy and soy isoflavone consumption in both women and men. Soy consumption has been suggested to exert potentially cancer-preventive effects in premenopausal women, such as increased menstrual cycle length and sex hormone-binding globulin levels and decreased estrogen levels. There has been some concern that consumption of phytoestrogens might exert adverse effects on mens fertility, such as lowered testosterone levels and semen quality. The studies in women have provided modest support for beneficial effects. One cross-sectional study showed serum estrogens to be inversely associated with soy intake. Seven soy intervention studies controlled for phase of menstrual cycle. These studies provided 32200 mg/d of isoflavones and generally showed decreased midcycle plasma gonadotropins and trends toward increased menstrual cycle length and decreased blood concentrations of estradiol, progesterone and sex hormone-binding globulin. A few studies also showed decreased urinary estrogens and increased ratios of urinary 2-(OH) to 16
-(OH) and 2-(OH) to 4-(OH) estrogens. Soy and isoflavone consumption does not seem to affect the endometrium in premenopausal women, although there have been weak estrogenic effects reported in the breast. Thus, studies in women have mostly been consistent with beneficial effects, although the magnitude of the effects is quite small and of uncertain significance. Only three intervention studies reported hormonal effects of soy isoflavones in men. These recent studies in men consuming soyfoods or supplements containing 4070 mg/d of soy isoflavones showed few effects on plasma hormones or semen quality. These data do not support concerns about effects on reproductive hormones and semen quality.
KEY WORDS: phytoestrogen isoflavone menstrual cycle estrogen testosterone
This article has been cited by other articles:
![]() |
S.-A. Lee, X.-O. Shu, H. Li, G. Yang, H. Cai, W. Wen, B.-T. Ji, J. Gao, Y.-T. Gao, and W. Zheng Adolescent and adult soy food intake and breast cancer risk: results from the Shanghai Women's Health Study Am. J. Clinical Nutrition, June 1, 2009; 89(6): 1920 - 1926. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Messina, W. McCaskill-Stevens, and J. W. Lampe Addressing the soy and breast cancer relationship: review, commentary, and workshop proceedings. J Natl Cancer Inst, September 20, 2006; 98(18): 1275 - 1284. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Atkinson, J. W Lampe, D. Scholes, C. Chen, K. Wahala, and S. M Schwartz Lignan and isoflavone excretion in relation to uterine fibroids: a case-control study of young to middle-aged women in the United States. Am. J. Clinical Nutrition, September 1, 2006; 84(3): 587 - 593. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Morris, J. Thorpe, L. Ambrosio, and M. Santin The Soybean Isoflavone Genistein Induces Differentiation of MG63 Human Osteosarcoma Osteoblasts J. Nutr., May 1, 2006; 136(5): 1166 - 1170. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Liew, M. A Stagg, J. Chan, P. Collins, and K. T MacLeod Gender determines the acute actions of genistein on intracellular calcium regulation in the guinea-pig heart Cardiovasc Res, January 1, 2004; 61(1): 66 - 76. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. H Halsted Dietary supplements and functional foods: 2 sides of a coin? Am. J. Clinical Nutrition, April 1, 2003; 77(4): 1001S - 1007. [Abstract] [Full Text] [PDF] |
||||