From what I remember about phytoestrogens, they generally fit onto the oestrogen receptors but only have some, not all, of the effects of our own oestrogen. And each one will have a slightly different effect, which might differ from person to person. The idea is that if you have too much oestrogen, (which is basically my problem, even though I'm supposed to be entering menopause) then if you eat foods with phytoestogens they may effectively block some of your own oestrogen as they fit onto the receptors instead of your own. I've messed about a bit with a few things and have found a combination of herbs which do seem to help - some had entirely the wrong effect so it took a while! I've had the endo for over 30 years and it's been pretty progressive but every now and then I find something which turns the clock back a few years. It's all finally catching up with me though and I need to find a few more magic bullets so I can hold off the worst of the damage for as long as possible until I finally achieve cronehood.
I used to eat quite a lot of soy in the form of soy
milk as my son was allergic to cow's milk for many years, but when his allergy wore off we switched back to cow's milk as the old man preferred it and as his appetite was failing we used to make lots of milk-shakes and things for him. I didn't notice any improvement when I stopped taking soy, so I'm quite happy to experiment taking it again in case it helps. It's very hard to judge results these days though as hormones seem to be in a free-for-all rollercoaster ride rather than a cycle and it's very hard to judge what effect anything has as everything is just too random.
I spoke to my doctor about it all today and he basically shrugged at the soy milk and said it probably wouldn't do much for me, but was pleased that I'd managed to source some miso and told me to eat as much as I could. I think learning to make miso is now one of my new ambitions!