Dairy foods and nutrients in relation to risk of ovarian cancer and major histological subtypes
Abstract
Inconsistent
results for the role of
dairy food intake in relation to ovarian cancer
risk may reflect the potential adverse effects of lactose, which has
been hypothesized to increase gonadotropin levels, and the beneficial
anti-proliferative effects of calcium and vitamin D. Using data from the
New England case-control study (1909 cases; 1989 controls) we examined
dairy foods and nutrients in relation to risk of ovarian cancer overall,
histological subtypes, and rapidly fatal versus less aggressive
disease. We used logistic regression and polytomous logistic regression
to estimate odds ratios and 95% confidence intervals. In
models that
were simultaneously adjusted for total (dietary plus supplements)
calcium, total vitamin D and lactose, we observed a decreased overall
risk of ovarian cancer with high intake of total calcium (Quartile 4
(Q4, >1319 mg/day) vs. Quartile 1 (Q1, <655 mg/day), odds ratio
(OR)=0.62, 95% Confidence Interval (CI)=0.49 - 0.79); the
inverse
association was strongest for serous borderline and mucinous tumors.
High intake of total vitamin D was not associated overall with ovarian
cancer risk, but was inversely associated with risk of serous borderline
(Q4, >559 IU/day vs. Q1, <164 IU/day, OR=0.51, 95% CI=0.34-0.76)
and endometrioid tumors (Q4 vs. Q1, OR=0.55, 95% CI=0.39-0.80). We found
no evidence that lactose intake influenced ovarian cancer risk, or that
risk varied by tumor aggressiveness in the analyses of intake of dairy
foods and nutrients. The overall inverse association with high intake of
calcium, and the inverse associations of calcium and vitamin D with
specific histological subtypes warrant further investigation.
