Postmenopausal women who eat foods rich in estrogen-like plant chemicals called lignans have a decreased risk of developing breast cancer. In an analysis of more than 20 studies, it was found that postmenopausal women who reported the highest intakes of dietary lignans were 14 percent less likely to develop breast cancer than those with low intakes. See http://www.raysahelian.com/lignan.html for details.