Verified answer

http://envirocancer.cornell.edu/FactSheet/Diet/fs1...

I couldn't find any real answers but if you are concerned about them, the phytoestrogens in lentils is different than the phytoestrogens in soy beans.

Also looks like flax seed oil has the most, more than soy or lentils...

http://www.ehow.com/info_8253671_list-phytoestroge...

This last link has much information.

http://e.hormone.tulane.edu/learning/phytoestrogen...

Lentils contain 36 micrograms per 100 grams. To put that in perspective, soybeans have 103,920 micrograms per 100 grams.