I keep hearing that soy proteins promote estrogen production but I've never found an actual study with significative results proving this. Any sources?
There aren't any.
Here a good overview of what we do know:
https://nutritionfacts.org/video/who-shouldnt-eat-soy/
The "bad soy" story originates largely from Kaayla Daniel and has been thoroughly debunked.
http://gofitu.com/food-myths-debunked-great-soy-debate/
I keep hearing that soy proteins promote estrogen production but I've never found an actual study with significative results proving this. Any sources?