Intake of food groups and associated micronutrients in relation to risk ofearly-stage breast cancer

Epidemiologic studies have evaluated the risk of breast cancer related to d ietary fat intake, but only recently have other dietary factors received at tention. Frequent intakes of fruit, vegetables and fiber have been associat ed with low risk of the disease in some studies but results are inconsisten t. In a large case-control study of early-onset breast cancer, we evaluated risk related to a variety of food groups, associated micronutrients and no n-nutritive constituents. Cases treated with chemotherapy appeared to have altered reporting of food intake and were excluded. Analyses were restricte d to 568 cases with in situ and localized disease and 1,451 population-base d controls. Reduced risks were observed for high intake of cereals and grai ns [odds ratio (OR) = 0.84, 95% confidence interval (CI) = 0.6-1.1 for high est compared with lowest quartile], vegetables (OR = 0.86, 95% CI = 0.6-1.1 ), beans (OR = 0.87, 95% CI = 0.7-1.2) and fiber from beans (OR = 0.88, 95% CI = 0.7-1.2). However, no trends of decreasing risk across quartiles of i ncreasing intake were observed. Risk was not associated with dietary consti tuents related to these food groups including dietary fiber, carotenoids, v itamins A, C and E and folate. Incorporation of information from vitamin su pplements did not alter the results for micronutrients. Our data suggest th at intakes of cereals and grains, vegetables and beans are associated with minimal, if any, reduction in risk of early-stage breast cancer among young women. Int. J. Cancer 82:315-321, 1999. Published 1999 Wiley-Liss, Inc.dag ger