A new study says women who drink at least two cups of tea a day have a lower risk of developing ovarian cancer than those who do not drink tea at all.
Evidence from laboratory studies has always indicated that green and black tea preparations may protect against various cancers. But few epidemiological studies have examined the relationship between tea consumption and risk of ovarian cancer.
Susanna C Larsson and Alicja Wolk of the National Institute of Environmental Medicine in Stockholm prospectively examined this relationship in 61,057 women, aged 40 to 76, who were participants in a population-based Swedish study.
The volunteers completed a validated 67-item food frequency questionnaire at enrollment between 1987 and 1990, and were followed for cancer incidence through December 2004.
Sixty-eight per cent of the participants reported drinking tea (mainly black tea) at least once per month.
During an average follow-up of 15.1 years, 301 women were diagnosed as having invasive epithelial ovarian cancer.
'We observed a 46 per cent lower risk of ovarian cancer in women who drank two or more cups of tea per day compared with non-drinkers,' the authors reported.
Women who drank less than one cup of tea per day had an 18 per cent lower risk of ovarian cancer than non-drinkers. The risk was 24 per cent lower for women who drank one cup of tea per day.
'Each additional cup of tea per day was associated with an 18 per cent lower risk of ovarian cancer,' they said.
This association does not depend on lower coffee consumption among women with high tea consumption as coffee is not associated with ovarian cancer risk in this cohort, the authors wrote.
'Summary results from the study suggest tea consumption may lower the risk of ovarian cancer,' they said. However, they added, since prospective data on this relationship are scarce, the findings need confirmation by future studies.
The study has been published in the December 26 issue of the Archives of Internal Medicine.
