Background: Early life exposures, including diet, have been implicated in the etiology of breast cancer. Methods: A nested case-control study was conducted among participants in the Nurses' Health Study who completed a 24-item questionnaire about diet during high school. There were 843 eligible cases diagnosed between onset of study (1976) and before the return of the high school diet questionnaire (1986), who were matched 10:1 with controls on the basis of age. Results: Women who had, during adolescence, a higher consumption of eggs, vegetable fat and fiber had a lower risk of breast cancer, whereas risk of breast cancer was increased among women who consumed more butter. Conclusions: A possible association of elements of adolescent diet with risk of breast cancer is reported, but the findings require confirmation in prospective study.
