Noooooooooo!!!!!!!!
What I've read in the research is that the medical professionals are suggesting that men with prostate cancer should eat more soy, as the estrogen will compete with the testosterone for the receptor sites where testosterone will bind. This will actually help the cancer patients, since it seems that an overabundance of testosterone in prostate cancer patients aggregraves the condition.
Otherwise, I got the hint that a healthy man would have to eat A LOT of soy for it to adversely affect them. I wouldn't worry.
I just got back from yet another convention and spent a good deal of time in seminars for nutrition. Our lecturers did say that it is better to get your soy from plant derivatives than from the isoflavin supplements- so be sure to drink more soy and rice milk, eat more soy beans, and have more tofu.
Proven how? Remember, if it were that harmful, it would be more likely to be removed from the shelves by the FDA or at least written up in JAMA or some kind of health threat issued by the AMA or some other organization like that. There is a whole continent of people with many more people than what we have that rely on soy in its natural state as a major food source than us, and they aren't dropping dead from eating soy, nor are they having thyroid or brain shrinkage issues. They (Asians, as in, the ones who live in Asia) live healthier lives and have less obesity problems than we have in the USA too. I suppose they account for that in their reports in the links posted in the first post of this thread?
Koffee