Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology
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Cancer Epidemiol. Biomarkers Prev. · Jul 2003
Calcium, dairy products, and risk of prostate cancer in a prospective cohort of United States men.
Intake of calcium and/or dairy products has been associated with increased risk of prostate cancer in some epidemiological studies. One potential biological mechanism is that high calcium intake down-regulates 1,25 dihydroxy vitamin D(3), which may increase cell proliferation in the prostate. We examined the association between calcium, dairy intake, and prostate cancer incidence in the Cancer Prevention Study II Nutrition Cohort, a prospective cohort of elderly United States adults. ⋯ Dairy intake was not associated with prostate cancer risk. The association between prostate cancer and total calcium intake was strongest for men who reported not having prostate-specific antigen testing before 1992 (RR = 1.5, 95% CI = 1.1-2.0, P trend < 0.01 for >or= 2000 mg/day of total calcium; RR = 2.1, 95% CI = 1.3-3.4 >or=2000 mg/day of dietary calcium, P trend = 0.04). Our results support the hypothesis that very high calcium intake, above the recommended intake for men, may modestly increase risk of prostate cancer.