A new study has reported that dietary fiber and nuts consumed during adolescence is associated with reduced incidence of proliferative benign breast disease during adulthood. Proliferative benign breast disease is an indicator of increased breast cancer risk. The study included 29,480 women in the Nurses’ Health Study II who completed a high school diet questionnaire in 1998. A centralized pathology review was used to identify 682 proliferative benign breast disease cases in this group between 1991 and 2001.

Women in the highest fifth of adolescent fiber intake were found to have a 25% lower risk of proliferative benign breast disease than women in the lowest quintile. High school intake of nuts was also found to be associated with significantly reduced risk of benign breast disease. Women consuming at least two servings of nuts per week had a 36% lower risk than women consuming fewer than one serving per month. The results held when the analysis was restricted to the 142 prospective cases who had been diagnosed after having completed the high school diet questionnaire. The authors conclude that dietary intake of fiber and nuts during adolescence influences subsequent risk of benign breast disease and may be a means to prevent breast cancer.