Green Tea May Reduce Some Digestive Cancers
The findings were recently published online of the American Journal of Clinical Nutrition.
“For all digestive system cancers combined, the risk was reduced by 27% among women who had been drinking tea regularly for at least 20 years,” explained Sarah Nechuta, an assistance professor of Medicine at Vanderbilt University, in a prepared statement. “For colorectal cancer, risk was reduced by 29% among the long-term tea drinkers. These results suggest long-term cumulative exposure may be particularly important.”
In the study, the researchers aimed to look at the impact of green tea on cancer risk. They surveyed a group of women who were part of the Shanghai Women’s Health Study, which included an estimated 75,000 middle-aged and older Chinese women. The population-based study included initial interviews with participants on their tea drinking habits, such as the type of tea they consumed or the amount of tea that was consumed. Many of the women who participated in the study stated that they primarily consumed green tea.
Based on the findings, the scientists discovered that regular tea consumption for a minimum of three times a week over a six-month period was related to a 17% reduction of a combination of all digestive cancers. Furthermore, they found that higher level of tea consumption reduced the risk of cancer even more. In particular, the participants who consumed approximately two to three cups a day or a minimum of 150g of tea per month showed a 21% reduction of risk for developing digestive system cancers.
The team of investigators believes that there may be a number of factors that may have impacted the results. For one, tea includes polyphenols or natural chemicals that have catechins such as EGCG and ECG. More importantly, catechins have antioxidant properties and can help prevent cancer by lowering DNA damage and stopping the invasion and growth of tumor cells.
As well, the researchers saw that lifestyle factors could affect the risk of developing some digestive system cancers. They interviewed the participants on the types of food they ate on a daily basis, their exercise regime, the highest education they obtained and their current job. The scientists found that regular tea drinkers exercised more, ate more fruits and vegetables, reached higher education levels and were younger in age.
Lastly, Chinese women who did not drink nor smoke were included in the study to limit the possible impact that these two lifestyle factors would have on the individuals.