The fibre through its effect on fermentation increases esterification of bile acids reducing toxicity of the free bile acids and is involved in the production of butyrate with potential anticancer effects including breast cancer. The fibre reduces the enterohepatic circulation of the oestrogens leading to lower plasma oestrogen concentrations. The fibre complex contains bioactive compounds such as lignans and alkylresorcinols that are antioxidative and potentially anticarcinogenic. In addition, vitamins, minerals, and phytic acid in rye may provide protection against breast cancer.