Both published research and general observations have shown numerous health benefits of drinking tea in general, and green tea in particular. Many of these are covered in a previous article “the health benefits of drinking tea“. Of interest today is the anti-cancer properties of green tea, with particular regard to the liver.
Studies such as this one showing how “green tea kills breast cancer cells” concluded that ” the cytotoxic effect of GTPs [green tea polyphenols] against five human cancer cell lines and the mechanisms of apoptosis in MCF-7 cells induced by GTPs were studied. In summary, the results showed that GTPs
had broad-spectrum anti-tumor activities, especially for MCF-7 cells [a line of breast cancer cells].” And this one that illustrated how “green tea kills lung cancer cells” – which concluded that “all results demonstrate that EGCG [green tea catechin] … stimulates apoptotic induction.”
And there are more, not an infinite amount however as things that cannot be patented or heavily profited from with particular regards to cancer do not tend to get studied heavily. Regardless it is clear that there is benefit.
A less covered aspect in the studies surrounding green tea and cancer was information about the effects on liver cancer in particular and that is what the meta-analysis I’m writing about today explored. Here researchers from the pharmacy departments at the Tongji School of Medicine in Shanghai and the Second Military Medical University, among other institutions, set out to answer questions about effectiveness and dosage.
They found significant reductions in the development of liver cancer in people who drank more than 4 cups of green tea daily, with some of the strongest benefits in those who did so for 20 years or more. They concluded that a “significant dose-response association was found between green tea drinking and liver cancer risk” and “increasing green tea intake may have a preventive effect against liver cancer.”
Now interestingly Japan, a large green tea drinking country, has one of the highest rates of liver cancer in the industrialized world ( 1 ). Much of this is due to the incredible amounts of intravenous drug abuse following the second world war – thus leading to large number of hepatitis C infections which is a risk factor for liver cancer. According to this article in the japan times, “the Chemist Nagayoshi Nagai first synthesized methamphetamine from ephedrine in 1893, and this was used as a pick-me-up during World War II for military personnel”. After the war however many of military stock ended up being used by the public to the point where in 1954 “police reports estimated there 550,000 addicts in the country, with around 2 million people having tried the drug at some point in their life.”
The country as a whole, however, has some of the lowest cancer rates – the US is 9th and Japan is 49th in this list, and they consume some of the highest amounts of green tea worldwide. That statistical observation would seem to back the benefits of green tea on cancer. Perhaps they are also subconsciously healing their livers from the coping mechanisms that were used following one of the greatest tragedies in our modern times. But that’s a story for a different article altogether.
For now, it seems fairly clear that if you enjoy green tea you shouldn’t hesitate to keep drinking it.