Dietary Patterns and Prostate Cancer in the NHEFS Cohort

摘要

Ecologic studies implicate a 'western' diet in prostate cancer, but whether dietary patterns measured in individuals are associated with risk has not been studied previously. We used prospective data from the NHANES I epidemiologic Follow-up Study, with 136 cases among 3,779 men followed 1982-4 to 1992. Using principal components analysis, three patterns were identified: vegetable-fruit, red meat-starch, and southern. In proportional hazards models, southern pattern intake showed a risk reduction (3rd vs. 1st tertile RR 0.6, 95% CI 0.4-1.1) that approached statistical significance, was observed in black and non-black men, and was not attributable to intake of any individual foods or nutrients. A southern pattern may reflect a history of living in the South and serve as a marker of sunlight exposure and protection through 1,25- hydroxyvitamin D production. Other findings in the same sample also suggest the importance of a vitamin D-related pathway: Dairy intake (RR 2.2, 95% CI 1.3-4.0) , lowfat milk (RR 1.6, 95% CI 1.2-2.1), and calcium (RR 2.4, 95% CI 1.5-3.9) were associated with risk, while vitamin D intake was inversely associated (RR 0.5, 95% CI 0.3-1.0). High calcium intake may suppress 1,25-hydroxyvitamin D production, increasing prostate cancer risk. However, mechanisms linking dairy/ calcium to prostate cancer should be clarified and confirmed.