Preventing Prostate Cancer by Consuming Green Tea.
Source: Cancer Prevention Research
Prostate cancer is the most common form of cancer, excluding skin cancer, in men in the United States. It is primarily diagnosed in men over 65, although it may begin much earlier. Some cancers of the prostate are very slow growing, while others behave aggressively. Prostate cancer often metastasizes to other tissue, including the brain, lungs, lymph nodes, and bones. Early detection is critical in order to increase the chances for survival. The cancer can be felt upon digital rectal examination (DRE). These examinations are recommended routinely for all men over the age of 50 and high-risk men should commence at age 40.
Green tea is an evergreen shrub that has long been used in much of the world as a popular beverage and a respected medicinal agent. An early Chinese Materia Medica lists green tea as an agent to promote digestion, improve mental faculties, decrease flatulence and regulate body temperature. The earliest known record of consumption is around 2700 B.C. Ceremonies, celebrations, relaxation time and ordinary meals usually consist of tea in most parts of the world, except the United States, where coffee has become the most popular beverage. Unlike black tea (also Camellia sinensis) which is produced by oxidizing the young tea leaves, green tea is produced from steaming fresh leaves at high temperatures, thereby inactivating the oxidizing enzymes and leaving the polyphenol content intact.
A trial published in the journal, Cancer Prevention Research, assessed the effect of Polyphenon E (a capsule that contains catechins, a family of chemicals which are naturally found in green tea) in 26 men with prostate cancer who were scheduled to undergo a radical prostatectomy. The Polyphenon E pill contains a number of different polyphenols which researchers have previously shown that two of them (known as EGCG and ECG) have an effect on breast and prostate cancer cells in vitro by inhibiting a particular biochemical pathway that is associated with disease severity. The researchers in this trial investigated whether taking Polyphenon E orally may have the potential to lower the incidence and slow the progression of prostate cancer. The patients enrolled in the study consumed four capsules per day of the green tea extract, equivalent to 12 cups of tea, until the day before surgery. The average supplementation period was 34.5 days. The results revealed significant reductions in serum levels of HGF, VEGF and PSA after treatment, with some patients demonstrating reductions in levels of greater than 30 percent. The researchers concluded that these findings suggest a potential role for the green tea extract in the treatment or prevention of prostate cancer.1
1 McLarty J, Bigelow RL, Smith M, et al. Tea Polyphenols Decrease Serum Levels of Prostate-Specific Antigen, Hepatocyte Growth Factor, and Vascular Endothelial Growth Factor in Prostate Cancer Patients and Inhibit Production of Hepatocyte Growth Factor and Vascular Endothelial Growth Factor In vitro. Cancer Prev Res. Jun2009.