Green Tea

Also indexed as:Camellia sinensis, EGCG
Green Tea: Main Image© Steven Foster
Botanical names:
Camellia sinensis

Parts Used & Where Grown

All teas (green, black, and oolong) are derived from the same plant, Camellia sinensis. The difference is in how the plucked leaves are prepared. Green tea, unlike black and oolong tea, is not fermented, so the active constituents remain unaltered in the herb. The leaves of the tea plant are used both as a social and a medicinal beverage.

  • Reliable and relatively consistent scientific data showing a substantial health benefit.
  • Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
  • For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

This supplement has been used in connection with the following health conditions:

Used for AmountWhy
High Cholesterol
green tea extract providing 107–856 mg of EGCG daily in smaller divided doses and with food3 stars[3 stars]
Green tea has been shown to lower total and LDL-cholesterol levels and improve cardiovascular health. Though uncommon, liver injury can occur with long-term use of green tea extract or EGCG.
Metabolic Syndrome
600 to 900 mg of tea catechins daily3 stars[3 stars]
Strong evidence indicates green tea and black tea extracts can help individuals with metabolic syndrome reduce body weight, lower blood glucose levels, and raise HDL-cholesterol levels.
Obesity
An extract supplying 100–460 mg of EGCG per day3 stars[3 stars]
Green tea extract rich in polyphenols may support a weight-loss program by increasing energy expenditure and fat burning.
Abnormal Pap Smear
Twice weekly, apply a cream with 15% polyphenols to the cervix and/or take a 200 mg EGCG supplement daily   2 stars[2 stars]
A preliminary study found that cervical dysplasia improved following treatment with epigallocatechin-3-gallate, a green tea flavonoid, for 8 to 12 weeks.
Colon Cancer
Drink a few cups per day 2 stars[2 stars]
The polyphenols in green tea leaves may help protect against colon cancer.
Down Syndrome
Refer to label instructions as Green Tea Catechins2 stars[2 stars]
In double-blind studies of young adults with Down syndrome, supplementation with epigallocatechin-gallate (EGCG; a flavonoid present in green tea) significantly improved measures of cognitive function.
Influenza
Gargle with a liquid extract containing 200 mcg per ml three times per dayas Green Tea Catechins2 stars[2 stars]
In one study, elderly nursing home residents in Japan who gargled with a green tea extract were less likely to get the flu than those who gargled without the green tea extract.
Leukoplakia
3 grams daily of a combination of whole green tea, green tea polyphenols, and green tea pigments, along with painting the mixture on the lesions three times per day2 stars[2 stars]
A combination of whole green tea, green tea polyphenols, and green tea pigments painted on lesions may improve healing.
Prostate Cancer
Several cups per day (enough to provide 600 mg of catechins daily) 2 stars[2 stars]
Drinking green tea or taking green tea catechins may help prevent prostate cancer in men at high risk of developing the disease.
Sunburn
Apply a formula containing 10% green tea polyphenols before sun exposure2 stars[2 stars]
Green tea contains polyphenols that have antioxidant and anti-inflammatory activity, and studies have suggested that these polyphenols can protect skin against ultraviolet rays.
Type 2 Diabetes
The best effective dose is unknown, but doses providing 450 mg of total green tea polyphenols (catechins) daily are considered moderate; doses providing 800 mg of EGCG or more daily have been linked to liver injury and are not considered safe.2 stars[2 stars]
Green tea may protect cardiovascular health and improve metabolism.
Crohn’s Disease
Refer to label instructions 1 star[1 star]
Green tea is a tannin-containing herb that may be helpful to decrease diarrhea during acute flare-ups and has been used for this purpose in traditional medicine.
Hemochromatosis
Refer to label instructions 1 star[1 star]
High-tannin tea has been shown to reduce the need for blood removal from people with iron overload, or hemochromatosis, in an open study. The tea had to be taken with meals and without lemon or milk to be effective. Tea is believed to help in hemochromatosis by preventing iron absorption.
High Triglycerides
Refer to label instructions 1 star[1 star]
Drinking green tea may have a positive effect on triglyceride levels.
Hives
Refer to label instructions 1 star[1 star]
Two components of green tea, the polyphenols epigallocatechin (EGC) and epicatechin gallate (ECG), are reported to have an antihistamine effect.
Immune Function
Refer to label instructions 1 star[1 star]
Green tea has stimulated production of immune cells and has shown anti-bacterial properties in some studies.
Infection
Refer to label instructions 1 star[1 star]
Green tea is an herb that directly attack microbes.
Lung Cancer
Refer to label instructions 1 star[1 star]
Numerous preliminary studies have shown an association between drinking green tea and a reduced risk of several types of cancer including lung cancer.

Traditional Use (May Not Be Supported by Scientific Studies)

According to Chinese legend, tea was discovered accidentally by an emperor 4,000 years ago. Since then, Traditional Chinese Medicine has recommended green tea for headaches, body aches and pains, digestion, depression, immune enhancement, detoxification, as an energizer, and to prolong life.

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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2024.