The problem with worrying about phytoestrogens is that they exist in almost all plants (fruits and veggies), nuts, seeds, beans, etc. Not to mention that meat you eat contains normal animal estrogen. Of the foods which contain isoflavones, soy is not nearly the highest. That would most likely go to nuts and seeds. If they were so terrible for you, then almost nothing we eat would be safe. That is why not a single study has been conclusive about the negative effects of phytoestrogens. Those that have had some significant findings have not been reliable.