[VergeOfDiscovery]

Haven't tried it myself, but there's also Hops (as in beer hops).

This option crossed my mind again as I can't help notice how unintentionally busty some regular (male) beer drinkers are at the local pub. lol

Swansons offers an extract called: Estro8PN Hop Extract ("powerful phytoestrogens that outperforms soy-derived phytoestrogens")

Alcohol by itself is a pretty powerful pro-aromatase...I think the hops may be just gravy compared to that, though craft brews have a lot more hops than Budweiser/Miller Lite/etc...

I read about this long ago around the time I was 21 and perhaps used it as a reason to drink regularly, and well it didn't do all that much for breast growth, I haven't masculinized much since I was 21 either...

It's a very particular component of hops, 8-prenylnaringenin (which is the featured ingredient of the Estro8PN supplement), as the other related components are said to be "less than 1% of that of 8-prenylnaringenin" in potency. And "These results indicate that the endocrine properties of hops and hop products are due to the very high estrogenic activity of 8-prenylnaringenin." Haven't tried it myself, and the PubMed article cited seems to raise concerns about herbal preparations for breast enhancement that will leverage this. 

And yes, if alcohol alone were powerful enough pro-aromatase, I would have been a certifiable girl years ago!

The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoids.
https://www.ncbi.nlm.nih.gov/pubmed/11134162