Soy protein isolates of varying isoflavone content do not adversely affect semen quality in healthy young men.

Objective: To determine the effects of consumption of soy protein of varying isoflavone content on parameters of semen quality in healthy young men.

Design: Randomized crossover intervention.

Setting: University campus.

Soy protein isolates of varied isoflavone content do not influence serum thyroid hormones in healthy young men.

Objective: The ability of soy isoflavones to inhibit thyroid peroxidase and induce goiter in animals has generated concern regarding their potential antithyroid effects in humans. The purpose of this study was to determine the effects of soy protein isolates of varied isoflavone content on circulating thyroid hormones in healthy young men.

Design: Thirty-five healthy men (27.

Effect of soy protein varying in isoflavone content on serum lipids in healthy young men.

Background: Previous research supports a role for soy protein in reducing serum lipids; however, few studies involved healthy male subjects or focused on soy isoflavones (or did both).

Objective: The objective was to ascertain the effects of soy protein varying in isoflavone content on serum lipids in healthy young men.

Design: Thirty-five males (x +/- SD age: 27.

Soy protein isolates of varying isoflavone content exert minor effects on serum reproductive hormones in healthy young men.

Inverse associations between soy and prostate cancer and the contribution of hormones to prostate cancer prompted the current study to determine whether soy protein could alter serum hormones in men. Thirty-five men consumed milk protein isolate (MPI), low-isoflavone soy protein isolate (SPI) (low-iso SPI; 1.64 +/- 0.