Green Tea & Health

Camellia sinensis, the plant commonly referred to as green tea, has been the discussed for decades as having health promoting effects. Green tea contains many different flavinoid compounds. Flavinoids act as strong antioxidants in your body to neutralize free radicals. Aside from water, tea is the most widely consumed beverage in the world. Green tea makes up 20% of the total tea production.

Green tea contains about 10mg of caffeine per cup. Decaffeinated green tea is not recommended because of the process used to extract the caffeine from the tea leaves. Most common is solvent extraction where chemicals known as solvents are used to extract the caffeine causing the tea to become contaminated with the solvents.

Commonly used for weight loss, green tea helps regulate blood sugar, and thereby reduces appetite and food cravings. Theanine an amino acid and a powerful compound extracted from green tea is now being used for mood disorders and has been shown to enhance the anti-tumor activity of doxorubicin a common chemotherapeutic agent. In a recent study published in September 10, 2003 International Journal of Cancer, green tea has been shown to significantly reduce breast cancer risk in Asian-American women. There was no risk reduction in women who drank black tea only.

Most recently there has been some talk about the effects of green tea on cancer cells with studies showing a decrease in carcinogenic activity, decreased risk of prostate cancer, and increased apoptosis in cancer cells. Another study showed an increase in sex hormone binding globulin which lowered estradiol levels and ultimately breast cancer risk. One double-blind placebo controlled trial conducted on 51 women showed a 69% response rate in cervical dysplasia when supplemented with green tea extract orally and applied topically to the cervix as opposed to 10% response rate in the placebo group.

Green tea has been shown to decrease the growth of streptococcus in the mouth decreasing plaque formation.

Green tea does contain tannins, which can bind to minerals and decrease our absorption so it is important to not take your vitamin and mineral supplements with either coffee or tea.

The benefits of green tea are seen at higher doses averaging around four cups a day. For people who just don't like the taste of green tea I suggest supplementation. Good quality green tea supplements are highly concentrated and one serving is the equivalent of 10 cups of tea. I like to suggest to people who enjoy iced tea to just brew up some iced green tea at home and take it with them.

Some of the local tea and coffee shops will make unsweetened green tea for you. One of the things I have heard people complain about with tea is the acidity. Drinking green or any tea high in tannins on an empty stomach can cause nausea. It is important to eat before enjoying a good cup of tea either hot or iced.

Int J Cancer 2003;106:574-579.
Modern Phytotherapist 2002 vol 7#1
Prev Med. 1992 May;21(3):334-50.
Eur J Cancer Prev. 2003 Oct;12(5):383-90.
Protective effects of green tea extracts (polyphenon E and EGCG) on human cervical lesions.WS, Yoo J, Huh SW, Kim CK, Lee JM, Namkoong SE, Bae SM, Lee IP.
Kuhn, Merrily, Winston, David, Herbal Therapy and Supplements;a Scientific and Traditional Approach, Lippincott, NY.

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