Cancer is the leading cause of death in Japan. Approximately 70-80% of these deaths are caused by factors such as poor diet and smoking.
According to the Vital Statistics of Japan, the standardized mortality rate of cancer in Shizuoka Prefecture, where green tea is produced, is significantly lower than the national rate for both men and women.
In Nakakawane Town, a green tea-producing region in Shizuoka Prefecture, the percentage of males who develop stomach cancer is about one-fifth of the national average.
On the other hand, according to a study conducted by the Saitama Cancer Center, the consumption of green tea among the residents of Saitama Prefecture was surveyed and analyzed at three cups or less, four to nine cups, and ten or more, and the results showed that the incidence of cancer was reduced by more than 40% in both men and women who drank ten or more cups of green tea.
How does exactly the green tea prevent cancers?
The active oxygen scavenging and anti-mutation inhibitory effects of catechins are thought to be involved, but this has not been elucidated in detail.
Research into the prevention of cancer with green tea is entering a new stage of clinical research after epidemiological surveys and animal experiments.
Clinical trials on the cancer-preventing effects of green tea ingredients have been initiated in Japan, Europe and the United States. Much attention is being paid to the question of whether green tea ingredients are effective in humans. Let’s look forward to future research. ITO EN. © All Rights Reserved 伊藤園お茶百科ウェブサイト
It has been proven in animal studies as well as in clinical intervention studies that high consumption of green tea prevents cancer and is widely recognized worldwide.
Previous studies have shown that 1) green tea catechins inhibit cancer stem cell activity in a variety of organs 2) EGCG or green tea extract may enhance the effect of anticancer drugs when used in combination.
From biophysical studies using atomic force microscopy, we have found that green tea catechins harden the membranes of cancer cells and, as a result, inhibit the activation of receptor tyrosine kinases such as EGFR and AXL.
We believe that this cell membrane sclerosing effect is responsible for the miraculous medicinal properties of green tea catechins.
Recently, we found that treatment with green tea catechins restored the activity of cytotoxic T cells (CTLs) by suppressing the expression of the immune checkpoint molecule PD-L1, which is induced by EGF and IFN-γ.
In other words, green tea catechins restored the activity of CTLs suppressed by the immune checkpoint and activated anti-tumor immunity.
We hope to utilize green tea catechins, which have a variety of anti-cancer effects, and develop them into innovative cancer therapies. (article published on Jan 9,2020 by Saitama Cancer Center)
The health benefits of green tea have been attracting attention in Western countries as well.
In 1998, Dr. J.H. Weisberger of the American Health Foundation announced that green tea has a cancer-preventive effect. In 1998, Dr. J.H. Weisberger of the American Health Foundation announced that it had cancer-preventive effects. In recent years, research has become more detailed, including the prevention of metabolic syndrome and which stage of cancer it is effective in.