Lignans are phytoestrogens with antioxidant activity. Lignans are from the cell walls of plants and are found in a variety of foods, including flax seeds, soybeans, whole grain cereals, rye, broccoli, pumpkin seed and some berries. A recent prospective study, appearing in the Journal of the National Cancer Institute (2007; 99(6): 475-86), analyzed the lignan intake of 58,049 postmenopausal French women. There was a link between lignan intake and lower breast cancer risk. Intake was assessed in the women, who were not taking any sort of soy isoflavone supplement, with a self-administered dietary history questionnaire. The women in the top quartile of lignan intake had a 17% lower risk of developing breast cancer than the women in the quartile with the lowest lignan intake.

Research appearing in Cancer Causes and Control (2006; 17(10): 1253-61) looked at diet and breast cancer risk. The population-based, case-controlled study looked at 3,024 patients between the ages of 25 and 74 years and compared them to 3,420 matched controls. Participants were given a food frequency questionnaire. It was found that the incidence of breast cancer and diet during adolescence. Eating lignans and isoflavones (phytoestrogens) during the teen years reduces the chance of developing breast cancer later in life.