I've always said that there are traces of gross growth hormones in milk products from the injections in cows, just as many hormone-altering hormones as soy. I've always believed that your hormones will equally fluctuate with whey or soy because they both have traces of hormone altering hormones. You're doing better for yourself and your heart taking in soy protein.
The soy isoflavonoids in soybeans have to be EXTREMELY concentrated in order for a hormonal imbalance to occur. For example to show you just how much you would have to take in by means of soy for a woman to grow breasts is this:
Pueraria Mirifica: 1 gram a day for 3 months = 1 breast cup size growth
Red Clover: 100 grams a day (because Pueraria Mirifica is 100x stronger)
Soy Isoflavone: 3,000 grams a day (because Pueraria Mirifica is 3,000x stronger)
Pueraria Mirifica is the only natural herbal supplement that has been clinically show to increase levels of estrogen and breast size in women. Now since men naturally have higher levels of testosterone this would take even longer. You would have to take in 3,000 grams of soy isoflavonoids a day for about 2 months I'd say before you saw a big hormonal change or breast tissue growth in men.
on this website: http://www.soyfoods.com/nutrition/isofl ... ation.html
it shows you the isoflavone amount in common soy foods, as you can see tofu and soy milk only have 2 grams of soy isoflavone per serving. Eating a crazy 64 oz of tofu and a gallon of soymilk a day brings you at only 64 grams of soy isoflavonoids. You're still 2,936 grams of soy isoflavones short from getting enough to equal the same phytoestrogen count of 1 gram of pueraria mirifica.
Soy does not have enough phytoestrogens to alter a man's hormones.