Abstract
Background: Dairy foods and their constituents (lactose and calcium) have been hypothesized to promote ovarian carcinogenesis. Although case-control studies have reported conflicting results for dairy foods and lactose, several cohort studies have shown positive associations between skim milk, lactose, and ovarian cancer.
Methods: A pooled analysis of the primary data from 12 prospective cohort studies was conducted. The study population consisted of 553,217 women among whom 2,132 epithelial ovarian cases were identified. Study-specific relative risks and 95% confidence intervals were calculated by Cox proportional hazards models and then pooled by a random-effects model.
Results: No statistically significant associations were observed between intakes of milk, cheese, yogurt, ice cream, and dietary and total calcium intake and risk of ovarian cancer. Higher lactose intakes comparing ≥30 versus <10 g/d were associated with a statistically significant higher risk of ovarian cancer, although the trend was not statistically significant (pooled multivariate relative risk, 1.19; 95% confidence interval, 1.01-1.40; Ptrend = 0.19). Associations for endometrioid, mucinous, and serous ovarian cancer were similar to the overall findings.
Discussion: Overall, no associations were observed for intakes of specific dairy foods or calcium and ovarian cancer risk. A modest elevation in the risk of ovarian cancer was seen for lactose intake at the level that was equivalent to three or more servings of milk per day. Because a new dietary guideline recommends two to three servings of dairy products per day, the relation between dairy product consumption and ovarian cancer risk at these consumption levels deserves further examination. (Cancer Epidemiol Biomarkers Prev 2006;15(2):364–72)
- Dairy
- Ovarian Cancer
- Cohort Studies
- Diet and cancer
- Gynecologic cancers: ovarian
Footnotes
↵18 Smith-Warner SA, Spiegelman D, Ritz J, et al. Methods for retrospective pooling of results of studies: the Pooling Project of prospective studies of diet and cancer. Am J Epidemiol, in press.
↵19 A. Wolk, personal communication.
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Grant support: NIH grants CA098566 and CA55075.
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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Note: This study was done at Harvard School of Public Health, Boston, Massachusetts.
- Accepted December 1, 2005.
- Received August 3, 2005.
- Revision received October 26, 2005.
Volume 15, Issue 2
