Green Tea: Three glasses a day keeps cancer away
by JP Saleeby, MD
CMO for Zimetry
Breast and prostate cancer are among the leading causes of cancer death in the United States. Even with our advances in medicine these two types of malignancies claim 200,000 new victims annually and up to 50,000 deaths per year. Because of the latency in development of these two particular forms of cancers there is opportunity for prevention. Furthermore, reduction in the risk of recurrence if one is unlucky enough to be stricken with them in the first place is also important to consider. While there are several treatments for these cancers, prevention would the wisest choice. Since it can take 20 to 40 years to develop breast and prostate cancer, anyone wishing to prevent these diseases would be searching for something that was safe and effective for long-term use. Discovery of an easy, safe and not too expensive a regiment to radically diminish the chances of acquiring cancer would be wonderful. Consumed by millions in the Far East in recent years Americans have discovered green tea. Green tea is the unfermented cousin of the black tea most Westerners are accustomed to drinking. For hundreds of years this very popular drink has been praised for its health benefits by Traditional Chinese Medicine practitioners. In the alopathic peer reviewed literature we are now seeing scientific studies demonstrating the benefits of green tea.
Green tea, one of the most popular beverage in the Far East has been studied as a chemopreventive agent against cancers. This beverage, popular for over 4000 years and consumed in quantity only second to water, has stood the test of time so to speak. It is has been around long enough and consumed by millions of people to judge its safety and efficacy. Green tea comes from the evergreen Camellia sinensis and the dried leaf is infused with hot water to yield the beverage. Green tea has been scientifically studied and shown to diminish primary occurrence as well as recurrence of cancers of the colon, ovary, breast and prostate. There are certain flavonoids and polyphenols in tea that have potent antioxidant properties. This is just one of many mechanisms of action tea has on inhibiting cancer. Studies have shown that these flavanoids and polyphenols are very well absorbed when taken orally either in the form of a drink or in capsules. Unlike pharmaceutical agents that act on a single target when fighting cancer, the green tea polyphenols harbor a multidimensionality against tumorigenesis (tumor formation).
In research mice, Interluken-2 deficient specimens prone to cancer survived when given green tea polyphenols which were found to lower interferon-gamma and tumor necrosis factor-alpha. In human studies, there is overwhelming evidence that green tea reduces incidence of breast and prostate cancer as well as reduces recurrence in those treated by traditional means (chemo and surgery) for these cancers. Epidemiological studies have found a two-fold reduction in breast cancer in women who consistently consume green tea. Another study involving men found the relative risk for prostate cancer nearly one-fourth in those who drank at least three cups of green tea daily. This is big news for those at high risk for cancer, with family history, and even the cancer survivor.
Although safer than most chemotherapeutic drugs, one has to be remain diligent about caffeine if they are sensitive (there are decaffeinated formulas available). There is also the possibility of interaction with the blood thinner warfarin (Coumadin (R) ), since green tea contains vitamin K in significant quantities. Vitamin K counteracts the effects of warfarin warranting careful monitoring for those taking this drug and drinking large amounts of tea.
How much is enough? According to studies the average cup of green tea yields 50 to 150 mg of polyphenols depending on the amount of leaves used and the steeping time. Based on this at least three cups of (heartedly steeped) tea daily should provide 300 mg of the polyphenols. If you are not that big a tea-totter, you can also obtain this amount in a 400 mg (80% standardized extract) capsule. While higher doses seem to be very well tolerated the effect is dose dependent. Better protection against cancer is achieved obviously with higher doses, but one should consult a nutritionally minded physician or herbalist for guidance with anything over 5 glasses per day.
JP Saleeby, MD is chief medical officer for Zimetry. Additionally he practices integrative and functional medicine in North & South Carolina. He has been involved with Telemedicine since 2002 and Direct Access Testing since 2011. He can be reached at firstname.lastname@example.org
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