Thanks for the input. To answer your question, the "question" over soy causing cancer was in doubt. There was a post posted yesterday about cancer and soy. Peter himself answered it. I would link it to you but I can't work those things. Simply read the board under this post (it was on breast cancer etc.).
Also, I posted yesterday on the other topics regarding soy, trypsin, Alzheimer's etc. I posted some references and biochemistry under Peter's post on the same topic.
The interesting point you brought up was how much is too much soy and how do we find out this figure. I don't believe this will ever be found out because everyone is different. Personally I can tell because of palpation of the duodenum to feel for putrification of the protein owing to the inhibition of trypsin but this is not conclusive for everyone.
As for the good outweighing the bad, it does. Its like that with everything in reality. I know there are no magical scales but how do you suggest we, as doctors recommend anything. Its called the "risk-benefit" ratio. Its not a perfect way to go about things but if you have any other positive suggestions I'd like to hear it!! I agree that the soy/Alzheimer's link needs more research but everything to do with heath does. We have to make an educated call on these topics as Doctors/Naturopaths or we will end up eating NOTHING (During college I ate nothing but apples for a while!! Nuts eh!!).
The BEST way I feel we do this is to look at the "big picture". Sure, its great to know the biochem, explanations, etc. but the big picture is that countries which consume soy are healthier, live longest, AND have a low rate of Alzheimer's. Research is great, exciting, and interesting but history of the foods I believe is the best way to go.
I hope this clears things up from my point of view.
I have to thank you for "asking the questions" and challenging what is written anywhere. There realy needs to be more of it! And its good to look at the big picture as you do.