A new met-analysis shows that drinking five cups of green tea a day may reduce your risk of developing breast cancer by 22 per cent. This meta-analysis used the same data that was used for analysis by the FDA. The FDA has concluded that there is very little science to support the claims that green tea decreases the risk of cancer.
Various previous epidemiological and laboratory studies have linked green tea to reduced risks of breast, lung, prostate and ovarian cancer. As a result of these studies, sales for green tea have been steadily increasing in Europe and US.
Tea contains a compound called polyphenol, which is claimed to offer protection from cancer. While green tea contains between 30 and 40 per cent of water-extractable polyphenols, black tea contains only 3 to10 per cent polyphenols.
This meat-analysis is, published in the current issue of on-line journal Carcinogenesis. The study draws its conclusion for green tea from three cohort and one population-based study for green tea, while five cohort and eight case-control studies were analyzed for a link between black tea and breast cancer.
The researchers say that green tea users had approximately 20 per cent statistically significant reduction in risk of breast cancer. There was no such protective effect detected with black tea. Indeed, the results were contradictory: the cohort studies showed a small increased risk of breast cancer, while the case-control studies showed a small decreased risk. |
