For centuries, green tea has been used in traditional Chinese medicine to treat everything from headaches to depression. Depending on how it’s made, tea can either be green, black or Oolong, all of which are harvested from the leaves and buds of the same plant, Camellia sinensis. Differences in production methods change each tea’s chemical composition and oxidation levels, which is why they taste and smell so uniquely different from each other.
According to Dr. Christine Horner, green tea is a true superfood, defined as a nutrient-dense food with unusually high levels of healthful ingredients such as antioxidants, vitamins, minerals, anti-inflammatory compounds and others.
Many studies suggest that green tea consumption may protect against heart disease and some types of cancer, including prostate cancer. Most of the health benefits of green tea are thought to be due to powerful antioxidants called polyphenols, which include the catechin, although exactly how they benefit our health remains unknown.
Roughly one-third of a typical cup of green tea is made of catechins. Of these, epigallocatechin-3-gallate (EGCG) is the most prominent catechin and has been studied in great detail in terms of its health potential.
Laboratory and animal research on the effects of green tea in prostate cancer have been promising:
EGCG blocks the stimulating effect of androgen (male sex hormone) on human prostate tumor cells, slowing their growth and spread and increasing the rate at which they die.
Human prostate cancer cells pre-treated with EGCG were more likely to die when exposed to radiation than cells not treated with EGCG before radiation.
Mice bred to develop prostate cancer that were given green tea catechins for 24 weeks did not develop prostate cancer; in other words, green tea catechins appeared to delay the development of prostate cancer.
Mice given green tea polyphenols at different ages to match different stages of prostate cancer were tumor-free longer than water-fed mice; and mice that consumed green tea the earliest benefitted the most. Further, these polyphenols caused high levels of cell death, possibly limiting cancer from spreading to other parts of the body.
So far, population studies and clinical trials on humans have shown mixed results:
Of 60 men with high-grade prostatic neoplasia treated with green tea catechin capsules for a year, nine men in the control group were diagnosed with prostate cancer compared to one man in the green tea catechin group; suggesting that green tea catechins lowers risk of prostate cancer in high-risk patients. A two year follow-up showed that this effect was long-lasting.
Patients scheduled to undergo radical prostatectomy were given green tea, black tea or soda five times daily for five days. Prostate cancer cells treated with blood taken from patients after they drank tea grew and divided more slowly relative to cells from patients before they drank tea.
Given the powerful anti-cancer potential and other known health benefits of this centuries-old superfood, isn’t it time you added green tea to your diet today?