Everyone has heard the term “chemotherapy” and it conjures up scary, negative images. On the other hand, have you heard the term “chemoprevention”? The National Cancer Institute defines chemoprevention as “the use of pharmacologic or natural agents that inhibit the development of invasive cancer either by blocking the DNA damage that initiates carcinogenesis or by arresting or reversing the progression of premalignant cells in which such damage has already occurred.”[i] Or, put simply, using a medicine or natural substance that affects a cell’s genes to keep cancer from starting or developing further. While the word might be new, the idea behind it is as old as humankind. Many ancient peoples recognized that certain plants kept people healthy, or had curative properties.
Today, there is renewed interest in the chemoprevention properties of green tea. Laboratory studies on the certain constituents of green tea called polyphenols can suppress prostate cancer activity and even lead to cell death without affecting healthy cells. Some of the polyphenols known to have anti-cancer properties, like quercetin, are found in other plants. However, green tea has an abundance of a polyphenol called epigallocatechin-3-gallate (EGCG) that appears to be its strongest anti-cancer component. A giant human laboratory, Asia, is testimony to the chemopreventive power of green tea: 20% of the world’s green tea consumption occurs there – for over 5,000 years, tea in Asia has been the most consumed beverage after water. Asian men who drink green tea throughout their lives have the world’s lowest incidence of death from prostate cancer![ii] Interestingly, when Asian men relocate to the U.S. and switch to a westernized diet, their prostate cancer risk increases.
A study by Johnson et al. (2010) reported that “animal models have consistently shown that standardized green tea polyphenols when administered in drinking water delay the development and progression of PCa. Altogether, three clinical trials have been performed in PCa patients and suggest that green tea may have a distinct role as a chemopreventive agent.”[iii] Their research team found that EGCG targets some mechanisms that induce inflammation, which is a known culprit in creating a favorable cancer environment. EGCG seems to influence and inhibit cancer cell growth activity and viability. It also targets the DNA factors that allow cancer to reproduce itself, targets androgen receptors on prostate cancer cells, and lowers PSA.
To demonstrate the real effect of these processes on humans, a team of researchers at the at the Moffitt Cancer Center and Research Institute in Florida tracked 49 men who took green tea capsules for a year. The capsules contained 200 milligrams of decaffeinate green tea with concentrated EGCG, and the men took one capsule twice a day. The control group consisted of 48 men who took a placebo twice daily during the same year. All study participants had been previously diagnosed with precancerous prostate conditions, but not prostate cancer itself. They found that those taking the green tea capsules reduced their risk of progressing to full blown prostate cancer, as well as lowering their PSA.
All in all, a tea that has been consumed for countless centuries offers the promise of better prostate health and less incidence of prostate cancer. In fact, green tea may be equally chemopreventive for breast cancer and other tumor cancers. I invite you to look more deeply into the benefits of green tea, and perhaps you will consider adding it to your daily routine. After all, just taking a break to sip a cup of tea can be a meditative moment and reduce stress. Just think of all the benefits of this humble drink!
[ii] Olson, Samantha. “Ingredient In Green Tea Might Prevent Prostate Cancer And Kill Tumor Cells When They Appear.” Medical Daily, May 31, 2015. http://www.medicaldaily.com/ingredient-green-tea-might-prevent-prostate-cancer-and-kill-tumor-cellsa-when-they-335788
[iii] Johnson JJ, Bailey HH, Mukhtar H. Green tea polyphenols for prostate cancer chemoprevention: a translational perspective. Phytomedicine. 2010 Jan;17(1):3-13.