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Complementary Medicine - Cam

Green Tea

Green Tea

Uses

Common names:
Epigallocatechin Gallate
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.

What Are Star Ratings?

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.

3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.

2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.

1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

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

Used for Why
2 Stars
Abnormal Pap Smear
Twice weekly, apply a cream with 15% polyphenols to the cervix and/or take a 200 mg EGCG supplement daily  
A preliminary study found that cervical dysplasia improved following treatment with epigallocatechin-3-gallate, a green tea flavonoid, for 8 to 12 weeks.

In a preliminary study, women with cervical dysplasia were randomly assigned to receive either 200 mg per day of EGCG—a green tea  extract known as (-)-epigallocatechin-3-gallate—200 mg per day of poly E (another green tea extract), or no treatment (control group) for 8 to 12 weeks. More than 50% of the women receiving EGCG or poly E had an improvement in their Pap smear, compared with only 10% of the women in the control group.1

2 Stars
Colon Cancer
Drink a few cups per day
The polyphenols in green tea leaves may help protect against colon cancer.

Green tea and black tea (Camellia sinensis) have both been studied to determine whether they cause or prevent cancer. The evidence on the protective effect of either type of tea is inconsistent.2 , 3 , 4 , 5 , 6 , 7 , 8 , 9

A number of preliminary studies have shown an association between drinking green tea and a reduced risk of some types of cancer,10 , 11 , 12 , 13 including colon cancer.14 , 15 In contrast, preliminary studies found that consumers of black tea do not appear to have a reduced risk of any type of cancer.16 , 17 , 18 , 19

2 Stars
High Cholesterol
75 mg of theaflavins, 150 mg of green tea catechins, and 150 mg of other tea polyphenols daily
An extract of green tea, enriched with a compound present in black tea (theaflavins), has been found to lower serum cholesterol in people with moderately high cholesterol levels.
An extract of green tea, enriched with a compound present in black tea (theaflavins), has been found to lower serum cholesterol in a double-blind study of people with moderately high cholesterol levels. The average reduction in total serum cholesterol during the 12-week study was 11.3%, and the average reduction in LDL cholesterol was 16.4%. The extract used in this study provided daily 75 mg of theaflavins, 150 mg of green tea catechins, and 150 mg of other tea polyphenols.
2 Stars
High Cholesterol
3 cups daily
Green tea has been shown to lower total cholesterol levels and improve people’s cholesterol profile.

Green tea has been shown to lower total cholesterol and LDL cholesterol levels according to several preliminary and controlled trials.20 , 21 , 22 , 23 , 24 , 25 However, not all trials have found that green tea intake lowers lipid levels.26 Much of the research documenting the health benefits of green tea is based on the amount of green tea typically drunk in Asian countries—about three cups per day, providing 240 to 320 mg of polyphenols.

2 Stars
Influenza
Gargle with a liquid extract containing 200 mcg per ml three times per day
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.

In a preliminary study of elderly nursing home residents in Japan, only 1.3% of those who gargled with a green tea extract three times a day during the winter developed influenza, whereas 10.4% of those who gargled without the green tea extract developed the disease (a statistically significant difference). The presumed active ingredients in the extract were a group of flavonoids called catechins, which were present in the extract at half the concentration as that in green tea.27 It is possible, therefore, that gargling with green tea itself might also be effective for preventing the flu.

In a double-blind study of healthcare workers, the combination of 378 mg per day green tea catechins and 210 mg per day of theanine (another component of green tea) taken for 5 months reduced the incidence of influenza infection by 69%, when compared with a placebo.28

2 Stars
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 day
A combination of whole green tea, green tea polyphenols, and green tea pigments painted on lesions may improve healing.

In a double-blind trial, people with leukoplakia took 3 grams per day of a mixture of whole green tea , green tea polyphenols, and green tea pigments orally and also painted the mixture of the tea on their lesions three times per day for six months.29 Those in the green tea group had significant improvement in the healing of their lesions.

2 Stars
Obesity
An extract supplying 270 mg of EGCG and 150 mg of caffeine per day
Green tea extract rich in polyphenols may support a weight-loss program by increasing energy expenditure or by inhibiting fat digestion.

Green tea extract rich in polyphenols (epigallocatechin gallate, or EGCG) may support a weight-loss program by increasing energy expenditure or by inhibiting the digestion of fat in the intestine.30 Healthy young men who took two green tea capsules (containing a total of 50 mg of caffeine and 90 mg of EGCG) three times a day burned significantly more calories and oxidized significantly more fat than those who took caffeine alone or a placebo. In a preliminary study of moderately obese individuals, administration of a specific green tea extract (AR25) resulted in a 4.6% reduction in average body weight after 12 weeks. The amount of green tea extract used in this study supplied daily 270 mg of EGCG and 150 mg of caffeine.

While caffeine is known to stimulate metabolism, it appears that other substances besides caffeine were responsible for at least part of the weight loss. Although the extract produced few side effects, one individual developed abnormal liver function tests during the study. In another study, consuming approximately 12 ounces of oolong tea (a semifermented version of green tea) daily for 12 weeks reduced waist circumference and the amount of body fat in a group of normal-weight to overweight men. However, in another study, 300 mg per day of EGCG was no more effective than a placebo for promoting weight loss in overweight postmenopausal women.31 Additional studies are needed to confirm the safety and effectiveness of green tea extracts for promoting weight loss.

2 Stars
Prostate Cancer
Several cups per day (enough to provide 600 mg of catechins daily)
Drinking green tea or taking green tea catechins may help prevent prostate cancer in men at high risk of developing the disease.
In a double-blind trial, men with precancerous changes in the prostate received a green tea extract providing 600 mg of catechins per day or a placebo for one year. After one year, prostate cancer had developed in 3.3% of the men receiving the green tea extract and in 30% of those given the placebo, a statistically significant difference.32 These results suggest that drinking green tea or taking green tea catechins may help prevent prostate cancer in men at high risk of developing the disease.
2 Stars
Sunburn
Apply a formula containing 10% green tea polyphenols before sun exposure
Green tea contains polyphenols that have antioxidant and anti-inflammatory activity, and studies have suggested that these polyphenols can protect skin against ultraviolet rays.

Green tea (Camellia sinensis) contains polyphenols that have antioxidant and anti-inflammatory activity, and animal and preliminary human studies have suggested that these polyphenols, when given orally or used topically, can protect skin against ultraviolet rays.33 , 34 , 35 , 36 In a small, controlled human study, topical application of green tea extracts containing from 2.5 to 10% polyphenols significantly reduced the amount of burning from exposure to ultraviolet rays, with the 10% solution exerting greater protective effect.37

2 Stars
Type 2 Diabetes
Refer to label instructions
A meta-analysis of several studies found that green tea consumption may improve blood glucose control and insulin sensitivity.
A meta-analysis of 17 randomized controlled trials, including a total of 1,133 subjects (mostly overweight or obese, and/or having type 2 diabetes or borderline diabetes) found that green tea consumption significantly improved blood glucose control and insulin sensitivity.38
1 Star
Crohn’s Disease
Refer to label instructions
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.

Tannin-containing herbs may be helpful to decrease diarrhea during acute flare-ups and have been used for this purpose in traditional medicine. A preliminary trial using isolated tannins in the course of usual drug therapy for Crohn’s disease found them to be more effective for reducing diarrhea than was no additional treatment.39 Tannin-containing herbs of potential benefit include agrimony (Agrimonia spp.), green tea , oak , witch hazel , and cranesbill . Use of such herbs should be discontinued before the diarrhea is completely resolved; otherwise the disease may be aggravated.

1 Star
Hemochromatosis
Refer to label instructions
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-tannin tea has been shown to reduce the need for blood removal from people with iron overload, or hemochromatosis, in an open study.40 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.
1 Star
High Triglycerides
Refer to label instructions
Drinking green tea may have a positive effect on triglyceride levels.

Intake of three cups or less of green tea daily has been shown not to affect blood triglyceride levels.41 Intake of four or more cups per day has been correlated with lower triglyceride levels.42 Overall, the evidence is unclear on how much of an effect high levels of intake of green tea has on triglyceride levels.

1 Star
Hives
Refer to label instructions
Two components of green tea, the polyphenols epigallocatechin (EGC) and epicatechin gallate (ECG), are reported to have an antihistamine effect.

Two components of green tea , the polyphenols epigallocatechin (EGC) and epicatechin gallate (ECG),43 are reported to have an antihistamine effect. Some doctors recommend approximately 3 cups of green tea per day or about 3 grams of soluble components providing roughly 240 to 320 mg of polyphenols, although no human trials have studied the effects of green tea in people with hives.

1 Star
Immune Function
Refer to label instructions
Green tea has stimulated production of immune cells and has shown anti-bacterial properties in some studies.
Green tea has stimulated production of immune cells and has shown anti-bacterial properties in animal studies.44 , 45 , 46 More research is needed to evaluate the effectiveness of green tea in protecting against infection and other immune system-related diseases.
1 Star
Infection
Refer to label instructions
Green tea is an herb that directly attack microbes.
1 Star
Lung Cancer
Refer to label instructions
Numerous preliminary studies have shown an association between drinking green tea and a reduced risk of several types of cancer including lung cancer.

Numerous preliminary studies have shown an association between drinking green tea and a reduced risk of several types of cancer48 , 49 , 50 , 51 including lung cancer.52 In contrast, preliminary studies of black tea consumption have not found that it protected against any type of cancer.53 , 54 , 55

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.

How It Works

Common names:
Epigallocatechin Gallate
Botanical names:
Camellia sinensis

How It Works

Green tea contains volatile oils, vitamins, minerals, and caffeine , but the primary constituents of interest are the polyphenols, particularly the catechin called epigallocatechin gallate (EGCG). The polyphenols are believed to be responsible for most of green tea’s roles in promoting good health.56

Green tea has been shown to mildly lower total cholesterol levels and improve the cholesterol profile (decreasing LDL “bad” cholesterol and increasing HDL “good” cholesterol) in most,57 , 58 , 59 , 60 but not all,61 studies. Green tea may also promote cardiovascular health by making platelets in the blood less sticky.

Green tea has been shown to protect against the oxidation of cholesterol to a more toxic molecule (oxidized cholesterol).62 Consumption of green tea increases antioxidant activity in the blood.63 Oxidative damage to LDL can promote atherosclerosis . While population studies have suggested that consumption of green tea is associated with protection against atherosclerosis,64 the evidence is still preliminary.

Several animal and test tube studies have demonstrated an anticancer effect of polyphenols from green tea.65 , 66 , 67 In one of these studies, a polyphenol called catechin from green tea effectively inhibited metastasis (uncontrolled spread) of melanoma (skin cancer) cells.68 The polyphenols in green tea have also been associated with reduced risk of several types of cancer in humans.69 , 70 , 71 However, some human studies have found no association between green tea consumption and decreased cancer risk.72 , 73

In a double-blind trial, people with leukoplakia (a pre-cancerous oral condition) took 3 grams orally per day of a mixture of whole green tea, green tea polyphenols, and green tea pigments orally, and also painted a mixture of the tea on their lesions three times daily for six months.74 As compared to the placebo group, those in the green tea group had significant decreases in the pre-cancerous condition.

Compounds in green tea, as well as black tea, may reduce the risk of dental caries.75 Human volunteers rinsing with an alcohol extract of oolong tea leaves before bed each night for four days had significantly less plaque formation, but similar amounts of plaque-causing bacteria, compared to those with no treatment.76

Green tea polyphenols have been shown to stimulate the production of several immune system cells, and have topical antibacterial properties—even against the bacteria that cause dental plaque.77 , 78 , 79

One study found that intake of 10 cups or more of green tea per day improved blood test results, indicating protection against liver damage.80 Further studies are needed to determine if taking green tea helps those with liver diseases.

Tea flavonoids given by capsule reduced fecal odor and favorably altered the gut bacteria in elderly Japanese with feeding tubes living in nursing homes.81 The study was repeated in bedridden elderly not on feeding tubes, and green tea was again shown to improve their gut bacteria.82 These studies raise the possibility of using green tea in other settings where gut bacteria are disturbed, such as after taking antibiotics. Further studies are needed to clarify the role of green tea in this respect, however.

High-tannin tea has been shown to reduce the need for blood removal from people with iron overload, or hemochromatosis, in an open study.83 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.

In a double-blind trial, men with precancerous changes in the prostate received a green tea extract providing 600 mg of catechins per day or a placebo for one year. After one year, prostate cancer had developed in 3.3% of the men receiving the green tea extract and in 30% of those given the placebo, a statistically significant difference.84 These results suggest that drinking green tea or taking green tea catechins may help prevent prostate cancer in men at high risk of developing the disease.

There are four case reports in which certain types of leukemia or lymphoma (low grade B-cell malignancies) improved after the patients began taking green tea extracts.85

How to Use It

Much of the research documenting the health benefits of green tea is based on the amount of green tea typically consumed in Asian countries—about 3 cups (750 ml) per day (providing 240–320 mg of polyphenols).86 However, other research suggests as much as 10 cups (2,500 ml) per day is necessary to obtain noticeable benefits from green tea ingestion.87 , 88 To brew green tea, 1 teaspoon (5 grams) of green tea leaves are combined with 1 cup (250 ml) of boiling water and steeped for three minutes. Decaffeinated tea is recommended to reduce the side effects associated with caffeine , including anxiety and insomnia . Tablets and capsules containing standardized extracts of polyphenols, particularly EGCG, are available. Some provide up to 97% polyphenol content—which is equivalent to drinking 4 cups (1,000 ml) of tea. Many of these standardized products are decaffeinated.

Interactions

Common names:
Epigallocatechin Gallate
Botanical names:
Camellia sinensis

Interactions with Supplements, Foods, & Other Compounds

At the time of writing, there were no well-known supplement or food interactions with this supplement.

Interactions with Medicines

Certain medicines interact with this supplement.

Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • none

Reduce Side Effects

  • none

Support Medicine

  • none

Reduces Effectiveness

  • Cardec DM

    Tannins are a group of unrelated chemicals that give plants an astringent taste. Herbs containing high amounts of tannins may interfere with the absorption of ephedrine or pseudoephedrine taken by mouth.89 Herbs containing high levels of tannins include green tea , black tea, uva ursi  (Arctostaphylos uva-ursi), black walnut (Juglans nigra), red raspberry  (Rubus idaeus), oak  (Quercus spp.), and witch hazel  (Hamamelis virginiana).

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
  • Warfarin

    One man taking warfarin and one-half to one gallon of green tea (Camellia sinensis) per day developed signs based on laboratory testing suggesting his blood was too thick because the green tea was blocking the effect of warfarin.90 Removal of the green tea caused normalization of his blood tests. Those taking green tea and warfarin together should have their blood monitored regularly to avert any problems and should consult with a doctor, healthcare practitioner and/or pharmacist before taking any medication.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Potential Negative Interaction

  • none

Explanation Required

  • none

The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist.

Side Effects

Common names:
Epigallocatechin Gallate
Botanical names:
Camellia sinensis

Side Effects

Green tea is generally free of side effects. The most common adverse effects reported from consuming large amounts (several cups per day) of green tea are insomnia , anxiety , and other symptoms caused by the caffeine content in the herb.

An extract of green tea taken by healthy women with a meal inhibited the absorption of non-heme iron (e.g., the form of iron in plant foods) by 26%.91 Frequent use of green tea could, in theory, promote the development of iron deficiency in susceptible individuals.

There have been at least 34 case reports of people developing liver damage (sometimes severe) while consuming weight-loss products that contained concentrated extracts of green tea.92 A cause–effect relationship was not proven, and most of the products contained other ingredients in addition to green tea extract. However, researchers have concluded that green tea extract was the probable cause of liver damage in some of the cases.93 Scientists have cautioned against the use of large amounts, or concentrated extracts, of green tea. In addition, there is a case report in which a person developed thrombotic thrombocytopenic purpura (a condition in which a bruising develops as a result of a low platelet count) after consuming a weight-loss product that contained green tea extract for 2 months. Green tea was not proven to be the cause of this problem.94

References

1. Ahn WS, Yoo J, Huh SW, et al. Protective effects of green tea extracts (polyphenon E and EGCG) on human cervical lesions. Eur J Cancer Prev 2003;12:383-90.

2. Kono S, Ikeda M, Tokudome S, Kuratsune M. A case-control study of gastric cancer and diet in northern Kyushu, Japan. Jpn J Cancer Res 1988;79:1067-74.

3. Gao YT, McLaughlin JK, Blot WJ, et al. Reduced risk of esophageal cancer associated with green tea consumption. J Natl Cancer Inst 1994;86:855-8.

4. Ji BT, Chow WH, Hsing AW, et al. Green tea consumption and the risk of pancreatic and colorectal cancers. Int J Cancer 1997;70:255-8.

5. Ohno Y, Wakai K, Genka K, et al. Tea consumption and lung cancer risk: A case-control study in Okinawa, Japan. Jpn J Cancer Res 1995;86:1027-34.

6. Fujiki H. Two stages of cancer prevention with green tea. J Cancer Res Clin Oncol 1999;125:589-97 [review].

7. Goldbohm RA, Hertog MGL, Brants HAM, et al. Consumption of black tea and cancer risk: A prospective cohort study. J Natl Cancer Inst 1996;88:93-100.

8. Heilbrun L, Nomura A, Stemmermann G. Black tea consumption and cancer risk: A prospective study. Br J Cancer 1986;54:677-83.

9. Phillips RL, Snowdon DA. Dietary relationship with fatal colorectal cancer among Seven-Day Adventists. J Natl Cancer Inst 1985;74:307-17.

10. Kono S, Ikeda M, Tokudome S, Kuratsune M. A case-control study of gastric cancer and diet in northern Kyushu, Japan. Jpn J Cancer Res 1988;79:1067-74.

11. Gao YT, McLaughlin JK, Blot WJ, et al. Reduced risk of esophageal cancer associated with green tea consumption. J Natl Cancer Inst 1994;86:855-8.

12. Ji BT, Chow WH, Hsing AW, et al. Green tea consumption and the risk of pancreatic and colorectal cancers. Int J Cancer 1997;70:255-8.

13. Ohno Y, Wakai K, Genka K, et al. Tea consumption and lung cancer risk: A case-control study in Okinawa, Japan. Jpn J Cancer Res 1995;86:1027-34.

14. Fujiki H. Two stages of cancer prevention with green tea. J Cancer Res Clin Oncol 1999;125:589-97 [review].

15. Yang G, Shu XO, Li H, et al. Prospective cohort study of green tea consumption and colorectal cancer risk in women. Cancer Epidemiol Biomarkers Prev 2007;16:1219-23.

16. Goldbohm RA, Hertog MGL, Brants HAM, et al. Consumption of black tea and cancer risk: A prospective cohort study. J Natl Cancer Inst 1996;88:93-100.

17. Heilbrun L, Nomura A, Stemmermann G. Black tea consumption and cancer risk: A prospective study. Br J Cancer 1986;54:677-83.

18. Phillips RL, Snowdon DA. Dietary relationship with fatal colorectal cancer among Seven-Day Adventists. J Natl Cancer Inst 1985;74:307-17.

19. Shimizu M, Fukutomi Y, Ninomiya M, et al. Green tea extracts for the prevention of metachronous colorectal adenomas: a pilot study. Cancer Epidemiol Biomarkers Prev 2008;17:3020-5.

20. Kono S, Shinchi K, Ikeda N, et al. Green tea consumption and serum lipid profiles: A cross-sectional study in Northern Kyushu, Japan. Prev Med 1992;21:526-31.

21. Yamaguchi Y, Hayashi M, Yamazoe H, et al. Preventive effects of green tea extract on lipid abnormalities in serum, liver and aorta of mice fed an atherogenic diet. Nip Yak Zas 1991;97:329-37.

22. Sagesaka-Mitane Y, Milwa M, Okada S. Platelet aggregation inhibitors in hot water extract of green tea. Chem Pharm Bull 1990;38:790-3.

23. Stensvold I, Tverdal A, Solvoll K, et al. Tea consumption. Relationship to cholesterol, blood pressure, and coronary and total mortality. Prev Med 1992;21:546-53.

24. Wu AH, Spicer D, Stanczyk FZ, et al. Effect of 2-month controlled green tea intervention on lipoprotein cholesterol, glucose, and hormone levels in healthy postmenopausal women. Cancer Prev Res 2012;5:393-402.

25. Zheng XX, Xu YL, Li SH, et al. Green tea intake lowers fasting serum total and LDL cholesterol in adults: a meta-analysis of 14 randomized controlled trials. Am J Clin Nutr 2011;94:601-10.

26. Tsubono Y, Tsugane S. Green tea intake in relation to serum lipid levels in middle-aged Japanese men and women. Ann Epidemiol 1997;7:280-4.

27. Yamada H, Takuma N, Daimon T, Hara Y. Gargling with tea catechin extracts for the prevention of influenza infection in elderly nursing home residents: a prospective clinical study. J Altern Complement Med 2006;12:669-72.

28. Matsumoto K, Yamada H, Takuma N, et al. Effects of green tea catechins and theanine on preventing influenza infection among healthcare workers: a randomized controlled trial. BMC Complement Altern Med 2011;11:15.

29. Li N, Sun Z, Han C, Chen J. The chemopreventive effects of tea on human oral precancerous mucosa lesions. Proc Soc Exp Biol Med 1999;220:218-24.

30. Nagao T, Hase T, Tokimitsu I. A green tea extract high in catechins reduces body fat and cardiovascular risks in humans. Obesity 2007;15:1473-83.

31. Hill AM, Coates AM, Buckley JD, et al. Can EGCG reduce abdominal fat in obese subjects? J Am Coll Nutr 2007;26:396S-402S.

32. Bettuzzi S, Brausi M, Rizzi F, et al. Chemoprevention of human prostate cancer by oral administration of green tea catechins in volunteers with high-grade prostate intraepithelial neoplasia: a preliminary report from a one-year proof-of-principle study. Cancer Res 2006;66:1234-40.

33. Graham HN. Green tea composition, consumption, and polyphenol chemistry. Prev Med 1992;21:334-50.

34. Kim J, Hwang JS, Cho YK, et al. Protective effects of (-)-epigallocatechin-3-gallate on UVA- and UVB-induced skin damage. Skin Pharmacol Appl Skin Physiol 2001;14:11-9.

35. Katiyar SK. Skin photoprotection by green tea: antioxidant and immunomodulatory effects. Curr Drug Targets Immune Endocr Metabol Disord 2003;3:234-42 [review].

36. Katiyar SK, Perez A, Mukhtar H. Green tea polyphenol treatment to human skin prevents formation of ultraviolet light B-induced pyrimidine dimers in DNA. Clin Cancer Res 2000;6:3864-9.

37. Elmets CA, Singh D, Tubesing K, et al. Cutaneous photoprotection from ultraviolet injury by green tea polyphenols. J Am Acad Dermatol 2001;44:425-32.

38. Liu K, Zhou R, Wang B, et al. Effect of green tea on glucose control and insulin sensitivity: a meta-analysis of 17 randomized controlled trials.Am J Clin Nutr2013;98:340–48.

39. Plein K, Burkard G, Hotz J. Treatment of chronic diarrhea in Crohn disease. A pilot study of the clinical effect of tannin albuminate and ethacridine lactate. Fortschr Med 1993;111:114-8 [in German].

40. Kaltwasser JP, Werner E, Schalk K, et al. Clinical trial on the effect of regular tea drinking on iron accumulation in genetic haemochromatosis. Gut 1998;43:699-704.

41. Tsubono Y, Tsugane S. Green tea intake in relation to serum lipid levels in middle-aged Japanese men and women. Ann Epidemiol 1997;7:280-4.

42. Imai K, Nakachi K. Cross sectional study of effects of drinking green tea on cardiovascular and liver diseases. BMJ 1995;310:693-6.

43. Matsuo N, Yamada K, Shoji K, et al. Effect of tea polyphenols on histamine release from rat basophilic leukemia (RBL-2H3) cells: the structure-inhibitory activity relationship. Allergy 1997;52:58-64.

44. Stoner GD, Mukhtar H. Polyphenols as cancer chemopreventive agents. J Cell Bioch 1995;22:169-80.

45. You SQ. Study on feasibility of Chinese green tea polyphenols (CTP) for preventing dental caries. Chin J Stom 1993;28(4):197-9.

46. Hamilton-Miller JM. Antimicrobial properties of tea (Camellia sinensis L.). Antimicrob Agents Chemother 1995;39:2375-7.

47. Shanafelt TD, Lee YK, Call TG, et al. Clinical effects of oral green tea extracts in four patients with low grade B-cell malignancies. Leuk Res 2006;30:707-12.

48. Kono S, Ikeda M, Tokudome S, Kuratsune M. A case-control study of gastric cancer and diet in northern Kyushu, Japan. Jpn J Cancer Res 1988;79:1067-74.

49. Gao YT, McLaughlin JK, Blot WJ, et al. Reduced risk of esophageal cancer associated with green tea consumption. J Natl Cancer Inst 1994;86:855-8.

50. Ji BT, Chow WH, Hsing AW, et al. Green tea consumption and the risk of pancreatic and colorectal cancers. Int J Cancer 1997;70:255-8.

51. Fujiki H. Two stages of cancer prevention with green tea. J Cancer Res Clin Oncol 1999;125:589-97 [review].

52. Ohno Y, Wakai K, Genka K, et al. Tea consumption and lung cancer risk: A case-control study in Okinawa, Japan. Jpn J Cancer Res 1995;86:1027-34.

53. Goldbohm RA, Hertog MGL, Brants HAM, et al. Consumption of black tea and cancer risk: A prospective cohort study. J Natl Cancer Inst 1996;88:93-100.

54. Heilbrun L, Nomura A, Stemmermann G. Black tea consumption and cancer risk: A prospective study. Br J Cancer 1986;54:677-83.

55. Phillips RL, Snowdon DA. Dietary relationship with fatal colorectal cancer among Seven-Day Adventists. J Natl Cancer Inst 1985;74:307-17.

56. Graham HN. Green tea composition, consumption, and polyphenol chemistry. Prev Med 1992;21:334-50.

57. Kono S, Shinchi K, Ikeda N, et al. Green tea consumption and serum lipid profiles: A cross-sectional study in Northern Kyushu, Japan. Prev Med 1992;21:526-31.

58. Yamaguchi Y, Hayashi M, Yamazoe H, et al. Preventive effects of green tea extract on lipid abnormalities in serum, liver and aorta of mice fed an atherogenic diet. Nip Yak Zas 1991;97:329-37.

59. Sagesaka-Mitane Y, Milwa M, Okada S. Platelet aggregation inhibitors in hot water extract of green tea. Chem Pharm Bull 1990;38:790-3.

60. Stensvold I, Tverdal A, Solvoll K, et al. Tea consumption. Relationship to cholesterol, blood pressure, and coronary and total mortality. Prev Med 1992;21:546-53.

61. Tsubono Y, Tsugane S. Green tea intake in relation to serum lipid levels in middle-aged Japanese men and women. Ann Epidemiol 1997;7:280-4.

62. Serafini M, Ghiselli A, Ferro-Luzzi A. In vivo antioxidant effect of green tea in man. Eur J Clin Nutr 1996;50:28-32.

63. Benzie IF, Szeto YT, Strain JJ, Tomlinson B. Consumption of green tea causes rapid increase in plasma antioxidant power in humans. Nutr Cancer 1999;34:83-7.

64. Sasazuki S, Komdama H, Yoshimasu K, et al. Relation between green tea consumption and severity of coronary atherosclerosis among Japanese men and women. Ann Epidemiol 2000;10:401-8.

65. Suganuma M, Okabe S, Sueoka N, et al. Green tea and cancer chemoprevention. Mutat Res 1999;428:339-44.

66. Weisberger JH, Rivenson A, Garr K, et al. Tea, or tea and milk, inhibit mammary gland and colon carcinogenesis in rats. Cancer Lett 1997;114:323-7.

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