The medicinal properties of green tea have long made it a natural weight-loss remedy. And in addition to its many other health benefits, research has shown that drinking green tea can also help prevent men from developing prostate cancer.
Twenty percent of the world's total green tea consumption occurs in Asia, where death rates from prostate cancer are among the lowest. In addition, the risk of acquiring prostate cancer seems to increase when men from Asia change their original diet as they migrate to the United States.
Among the different varieties of cancer, prostate cancer is the second most common among men. Experts estimate that 220,000 cases will be diagnosed within the United States this year, with around 80 percent of men being diagnosed by the time they are 80 years old.
Research in prostate cancer has recently focused on chemoprevention, which is the use of agents for the prevention of the disease. A research team led by Dr. Nagi Kumar from the Moffitt Cancer Center has released the results of a study showing the effectiveness of green tea in preventing prostate cancer.
The study involved a random trial that analyzed the effectiveness and safety of the components in green tea in preventing the development of prostate cancer within men who already had pre-malignant lesions.
Laboratory tests determined that substances called catechins – found in green tea – prevent the growth of cancer cells, along with their invasion and motility, leading to the death of the cells. The catechins also prevented and reduced the growth of tumors in animal models.
Among the catechins in green tea that protect against prostate cancer, the most potent and abundant one is epigallocatechin-3-gallate, or EGCG. Looking to test whether a one-year intervention using catechins found in green tea could prevent the development of prostate cancer in high-risk men, the researchers used decaffeinated green tea capsules called Polyphenon E, which contained several catechins — mostly EGCG.
The researchers gave the capsules to their subjects twice daily, in 200 milligram doses. The subjects were men with HGPIN (high-grade intraepithelial neoplasia) or ASAP (atypical small acinar proliferation) — basically, lesions in the prostate that can be diagnosed as prostate cancer.
The tests revealed that for men with HGPIN, consuming Polyphenin E reduced the chance of developing ASAP and prostate cancer. In addition, the men had lower levels of PSA, or prostate specific antigen, which is a marker of how high a person's risk is to acquiring prostate cancer.
The results of the study will be presented in the annual meeting of the American Society of Clinical Oncology in Chicago.
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