ScienceDaily (Sep. 13, 2011) — Phytoestrogens are plant compounds which, in the human body, can attach to the receptors for the female sexual hormone estrogen and which are taken in with our daily diet. A number of findings have attributed a cancer protective effect to these plant hormones. At DKFZ, a team headed by Prof. Dr. Jenny Chang-Claude summarized the results of several studies in a meta-analysis last year and showed that a diet rich in phytoestrogens lowers the risk of developing breast cancer after menopause. Now the Heidelberg researchers wanted to find out whether phytoestrogens also have an influence on the course of breast cancer. Prior investigations on this topic had provided contradictory results.