Association of diet and mammographic breast density in the Minnesota breast cancer family cohort

Mammographic breast density is a significant risk factor for breast cancer. The present report analyzes the association of breast density and dietary factors in 1508 women in a historical cohort study of breast cancer familie s in Minnesota. Diet was assessed by a semiquantitative food frequency ques tionnaire, Percent breast density was estimated visually by a radiologist e xperienced in mammography, The association of percent breast density with q uartiles of energy-adjusted dietary intakes was examined in analysis of cov ariance models adjusting for potential confounding effects of age, body mas s index, and other covariates as well as correcting for familial correlatio n. Analyses were performed on all women combined and were also stratified b y menopausal status. Among premenopausal women, percent breast density was positively associated with intakes of polyunsaturated fat, polyunsaturated: saturated fat ratio, and vitamins C and E and was inversely associated with saturated fat and total dairy intake. Among postmenopausal women, vitamin B-12 was linearly associated with increased breast density. The positive as sociations for vitamin C and B-12 were attributable to supplement intake on ly. There was a suggestive positive trend between breast density and daily alcohol consumption in both premenopausal and postmenopausal women, After a djustment for other sources of alcohol, only wine intake among postmenopaus al women was significant such that white wine showed a positive association and red wine an inverse association with percent breast density, There was no association with other examined dietary factors. The cross-sectional di fferences in breast density across levels of dietary factors were small in magnitude but may have implications for breast cancer risk.