http://en.wikipedia.org/wiki/Phytoestrogens
oh and the study that says 'males' aren't affected by plant ... phytoestrogens (simply chemicals that act like estriadol) ... well they don't take into account people who - might not be - 100% male as far as physiology. There may be a percentage of the population who are more susceptable to something like plant based estriadol than most regardless of outward gender characteristics.