Tea consumption and ovarian cancer risk in a population-based cohort.
BACKGROUND
Substantial evidence from laboratory studies indicates that green and black tea preparations may protect against various cancers. Few epidemiologic studies, however, have examined the relationship specifically between tea consumption and risk of ovarian cancer.


METHODS
We prospectively examined the association between tea consumption and risk of ovarian cancer in 61 057 women aged 40 to 76 years who were participants in the population-based Swedish Mammography Cohort. Participants completed a validated 67-item food frequency questionnaire at enrollment between 1987 and 1990 and were followed for cancer incidence through December 2004.


RESULTS
During an average follow-up of 15.1 years, 301 incident cases of invasive epithelial ovarian cancer were ascertained. Tea consumption was inversely associated with the risk of ovarian cancer after controlling for potential confounders (P for trend, .03). Compared with women who never or seldom (less than monthly) consumed tea, the multivariate hazard ratios for those who consumed less than 1 cup per day, 1 cup per day, and 2 or more cups per day were 0.82 (95% confidence interval [CI], 0.62-1.08), 0.76 (95% CI, 0.56-1.04), and 0.54 (95% CI, 0.31-0.91), respectively. Each additional cup of tea per day was associated with an 18% lower risk of ovarian cancer (multivariate hazard ratio, 0.82; 95% CI, 0.68-0.99).


CONCLUSIONS
These results suggest that tea consumption is associated with a reduced risk of epithelial ovarian cancer in a dose-response manner.
Larsson
Susanna C
SC
Division of Nutritional Epidemiology, The National Institute of Environmental Medicine, PO Box 210, Karolinska Institutet, SE-171 77 Stockholm, Sweden. susanna.larsson@imm.ki.se
Wolk
Alicja
A
D000328:Adult; D000368:Aged; D001628:Beverages; D004327:Drinking Behavior; D005247:Feeding Behavior; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000453:epidemiology* / Q000517:prevention & control; D011446:Prospective Studies; D012044:Regression Analysis; D018570:Risk Assessment; D013548:Sweden; D013662:Tea
D013662:Tea