Lignans, what are they

Can someone help me out with what these things are? I did a google search and it said that they help reduce cancer and other good things. The thing that I am concerned about is that lignans are phytoestrogens, and I figured that they would lower my Test levels. I read on and supposedly they grab onto estrogens in the human body so they can be released from the body. So, can anyone help me out?

As far as what I know, lignans serve as aromatase inhibitors (like zinc) as well as being good antioxidants. This means that it should actually increase or at the very least maintain adequate levels of Testosterone by preventing the aromatase enzyme from converting Testosterone into Estrogen. Hopefully this can help a bit.