That trend is continuing, according to the results of a large new study which found that older women who regularly drink green tea may have less risk of developing colon, stomach and throat cancers, compared to women who don't consume tea at all.
Researchers discovered that of more than 69,000 Chinese women who they followed for more than 10 years, those who drank green tea at least three times per week were 14 percent less likely to develop a cancer afflicting the digestive system, Reuters reported, citing the scientists' work.
Generally speaking, that meant those women had less of a chance of developing esophageal, stomach and colon cancers.
'Strong evidence' that green tea works to some extent
Scientists involved in this study were unsure if the green tea itself was responsible for the lower rates of cancer, but noted that those who drink it are very often more health conscious. However, several previous studies have suggested green tea helps prevent certain kinds of cancer, through its powerful antioxidant action.
Nevertheless, this most recent study attempted to account for the health-conscious aspect, according to Dr. Wei Zheng, head of epidemiology at Vanderbilt University School of Medicine in Nashville, who led the study. None of those involved in the study smoked or drank alcohol on a regular basis. In addition, researchers gathered information on their diets, exercise habits, medical history and weight.
Even with all of those factors added to the equation, women's tea habits remained linked to their risk of developing cancer, noted Zheng, adding that nevertheless, this type of study can't prove cause-and-effect.
And he said that past studies revealed conflicting findings on whether consumers of green tea honestly have lower cancer risks (though the anecdotal evidence, at least, is very strong, as we have shown in our coverage of this topic).
"All of those studies," Reuters reported, "are hampered by the fact that it's hard to isolate the effect of a single food in a person's diet on the risk of cancer."
Clinical trials are just about the only types of studies that are able to reveal evidence of cause-and-effect, where people are randomly selected to drink green tea in some form - or not at all. According to the National Cancer Institute, there have been few such studies.
Zheng and his team, referencing his own study, said that "strong evidence" from lab research in animals and human cells suggested that green tea has some potential as an anti-cancer agent in a report on their findings in the American Journal of Clinical Nutrition.
Nearly 30 percent improvement in cancer rates
As in previous studies examining a link between green tea and a reduction in cancer risk, they revealed that the beverage contains key antioxidant chemicals - particularly a substance known as EGCG - that may act to thwart the body-cell damage which can ultimately lead to cancer and other disease processes.
For their study, Zheng and his team used data from an 11-year running study of 69,000 middle-aged and older Chinese women. More than 19,000 of them were considered regular consumers of green tea, in that they drank it at least three times a week.
Over the time period, 1,255 women developed some form of cancer of the digestive system. But the data show that generally speaking, risks for developing disease were somewhat lower when a woman drank green tea often and over a long time.
For instance, women who told researchers they'd had green tea regularly for at least 20 years were 27 percent less likely than non-green tea drinkers to develop a cancer of the digestive system. Also, they were 29 percent less likely to develop colorectal cancer.
Most Recommended Green Tea Products：AriZona, Green Tea, with Pomegranate & Acai, 20 Tea Bags, 1.37 oz (38 g)
Now Foods, EGCg, Green Tea Extract, 400 mg, 180 Vcaps