"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," reported Susanna Larsson and Alicja Wolk in the latest issue of Archives of Internal Medicine.
Both green and black tea contain significant amounts of antioxidantpolyphenols, which have been shown to stop carcinogenesis inlaboratory-based cell studies. Numerous case-control studies have linkeddrinking tea to decreased risk of breast, prostate and other forms ofcancer.
The 15-year study from Sweden followed 61,057 women. Volunteers completed a67-item food frequency questionnaire between 1987 and 1990 as part of theenrolment for the Swedish Mammography Cohort, and followed for cancerincidence until December 2004. At baseline, 68 per cent of the womenreported drinking tea (mainly black tea) more than once a month.
Only 301 women were diagnosed as having invasive epithelial ovarian cancer.
The researchers from the National Institute of Environmental Medicine at the Karolinska Institutet in Stockholm said: "Tea consumption wasinversely associated with the risk of ovarian cancer. Each additional cup of tea per day was associated with an 18 per cent lower risk of ovarian cancer."
Ovarian cancer accounts for 4 per cent of all cancers diagnosed in womenglobally, with 190,000 new cases every year. In Europe there are 61,000 newcases each year, with the highest incidence rates found in the NorthernEuropean countries of the UK, Ireland, Denmark and Finland.
Professor Gordon McVie, senior consultant to the European Institute ofOncology, told NutraIngredients.com: "There are stacks of cancer studiesconcerning tea which are ambivalent. This new study is interesting. Theconclusion that two cups of tea a day is beneficial is statistically valid."
"Not too many people study ovarian cancer; we have no idea of the causes and diet must be considered to be a possible factor. These results [of theSwedish research] have to be taken seriously and are worthy of a prospectivestudy," he added.
The global tea market is worth €790m in sales annually.