Calcium, dairy foods, and risk of incident and fatal prostate cancer: the NIH-AARP Diet and Health Study.
Calcium and dairy foods in relation to prostate cancer were examined in the National Institutes of Health (NIH)-AARP (formerly known as the American Association of Retired Persons) Diet and Health Study (1995/1996-2001). Diet was assessed with a food frequency questionnaire at baseline. Multivariate relative risks and 95% confidence intervals were estimated by Cox regression. During up to 6 years of follow-up (n = 293,888), the authors identified 10,180 total prostate cancer cases (8,754 nonadvanced, 1,426 advanced, and 178 fatal cases). Total and supplemental calcium were unrelated to total and nonadvanced prostate cancer. However, a statistically nonsignificant positive association with total calcium was observed for advanced (> or = 2,000 vs. 500-<750 mg/day: relative risk (RR) = 1.25, 95% confidence interval (CI): 0.91, 1.71; p(trend) = 0.06) and fatal (> or = 1,000 vs. 500-<750 mg/day: RR = 1.39, 95% CI: 0.92, 2.09; p(trend) = 0.10) prostate cancer. Skim milk, but not other dairy foods, was associated with increased risk of advanced prostate cancer (> or = 2 vs. zero servings/day: RR = 1.23, 95% CI: 0.99, 1.54; p(trend) = 0.01). In contrast, calcium from nondairy foods was associated with lower risk of nonadvanced prostate cancer (> or = 600 vs. < 250 mg/day: RR = 0.82, 95% CI: 0.68, 0.99; p(trend) = 0.04). Although the authors cannot definitively rule out a weak association for aggressive prostate cancer, their findings do not provide strong support for the hypothesis that calcium and dairy foods increase prostate cancer risk.
Park
Yikyung
Y
Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20852, USA. parkyik@mail.nih.gov
Mitrou
Panagiota N
PN
Kipnis
Victor
V
Hollenbeck
Albert
A
Schatzkin
Arthur
A
Leitzmann
Michael F
MF
D000328:Adult; D000368:Aged; D002136:Calcium, Dietary / Q000008:administration & dosage / Q000009:adverse effects*; D003611:Dairy Products; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D011471:Prostatic Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000401:mortality*; D012042:Registries; D018570:Risk Assessment; D018426:SEER Program; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D014807:Vitamin D / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*
D002136:Calcium, Dietary; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D