Higher as well as regular tea consumption benefits found
The benefits of tea drinking have been shown again in a study that has found the risk of ovarian cancer is reduced in tea drinkers.
Curtin University PhD student Dada Su conducted a hospital based case control study in Guangzhou, China with 1,000 participants—500 patients with histologically confirmed epithelial carcinoma of the ovary and 500 unaffected women as controls—who completed a questionnaire about their tea consumption history.
The results display control subjects reporting higher tea consumption levels and prevalence (78.8 per cent) than the ovarian cancer patients (51.4 per cent), indicating that regular tea consumption is associated with a reduced risk of ovarian cancer (in the southern Chinese women surveyed).
Those involved in the study were found to drink a mixture of green, black and oolong tea.
The experimental association study did not examine the biological mechanisms and properties of tea involved with the prevention of ovarian cancer.
Study project leader and Curtin School of Public Health Professor Andy Lee says a dose-response relationship has also been established.
"It's not just the duration of tea drinking but also quantity of tea and the frequency of intake as well," he says.
"So the more cups you drink per day and the more the quantity of tea you drink the better the result (the lower the risk)."
Prof Lee says an important finding is that it is not just the green tea but also the oolong and black tea drinking, which has a similar effect.
The paper states that "regular drinking of green tea, black tea and/or oolong tea was associated with a lower risk of ovarian cancer, the adjusted odds ratio being 0.29 [95 per cent confidence interval 0.22–0.39] after accounting for confounding factors".
Prof Lee hopes further research will look at the long-term survival of the ovarian cancer patients, and whether tea drinking can enhance survival rates.
"At the moment we are only looking at the development of the cancer…but we also want to find out if the more you drink tea and the longer you drink it has an effect on the survival rate."
"We note that ovarian cancer has a very poor five year survival rate of about 43 per cent or so in Australia.
"So we want to see if those patients will actually improve survival rates if they continue to drink tea," he says.
Prof Lee says as a relatively safe beverage with no toxic or any other negative associated effects, the health message of tea drinking should be promoted.