Soy beans contain high levels of the isoflavones genistein and daidzein and their glycosides and have been implicated in the prevention of prostate cancer, possibly via their effects on sex hormone metabolism. The aim of this study was to assess the relation between dietary soy intake and sex hormone levels in a cross-sectional analysis of 696 men with a wide range of soy intakes. Soy milk intake was measured using a validated semiquantitative food frequency questionnaire, and serum hormone concentrations were measured by immunoassay. Multiple regression was used to investigate the association between soy milk intake, an index of isoflavone intake, and hormone levels after adjustment for pertinent confounders. Soy milk intake was not associated with serum concentrations of testosterone, free testosterone, androstanediol glucuronide, sex hormone-binding globulin, or luteinizing hormone. These results suggest that soy milk intake, as a marker of isoflavone intake, is not associated with serum sex hormone concentrations among free-living Western men.

Original publication




Journal article


Nutr Cancer

Publication Date





41 - 46


Adult, Androstanes, Beverages, Body Mass Index, Cross-Sectional Studies, Diet, Vegetarian, Exercise, Glucuronides, Gonadal Steroid Hormones, Great Britain, Humans, Isoflavones, Luteinizing Hormone, Male, Middle Aged, Regression Analysis, Sex Hormone-Binding Globulin, Smoking, Soybeans, Surveys and Questionnaires, Testosterone