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From the National Institutes of HealthNational Institutes of Health

Green tea


What is it?

Green tea is a product made from the Camellia sinensis plant. It can be prepared as a beverage, which can have some health effects. Or an “extract” can be made from the leaves to use as medicine.

Green tea is used to improve mental alertness and thinking.

It is also used for weight loss and to treat stomach disorders, vomiting, diarrhea, headaches, bone loss (osteoporosis), and solid tumor cancers.

Some people use green tea to prevent various cancers, including breast cancer, prostate cancer, colon cancer, gastric cancer, lung cancer, solid tumor cancers and skin cancer related to exposure to sunlight. Some women use green tea to fight human papilloma virus (HPV), which can cause genital warts, the growth of abnormal cells in the cervix (cervical dysplasia), and cervical cancer.

Green tea is also used for Crohn’s disease, Parkinson’s disease, diseases of the heart and blood vessels, diabetes, low blood pressure, chronic fatigue syndrome (CFS), dental cavities (caries), kidney stones, and skin damage.

Instead of drinking green tea, some people apply green tea bags to their skin to soothe sunburn and prevent skin cancer due to sun exposure. Green tea bags are also used to decrease puffiness under the eyes, as a compress for tired eyes or headache, and to stop gums from bleeding after a tooth is pulled.

Green tea in candy is used for gum disease.

Green tea is used in an ointment for genital warts. Do not confuse green tea with oolong tea or black tea. Oolong tea and black tea are made from the same plant leaves used to make green tea, but they are prepared differently and have different medicinal effects. Green tea is not fermented at all. Oolong tea is partially fermented, and black tea is fully fermented.

How effective is it?

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for GREEN TEA are as follows:

Likely effective for...

  • Genital warts. A specific green tea extract ointment (Veregen, Bradley Pharmaceuticals) is FDA-approved for treating genital warts.
  • Increasing mental alertness, due to the caffeine content of green tea.

Possibly effective for...

  • Preventing dizziness upon standing up (orthostatic hypotension) in older people.
  • Preventing bladder, esophageal, ovarian, and pancreatic cancers. Women who regularly drink tea, including green tea or black tea, appear to have a significantly lower risk of developing ovarian cancer compared to women who never or seldom drink tea. In one study, women who drank 2 or more cups of green tea each day had a 46% lower risk of getting ovarian cancer than women who didn’t drink green tea.
  • Reducing the risk or delaying the onset of Parkinson’s disease. Drinking one to four cups of green tea daily seems to provide the most protection against developing Parkinson’s.
  • Low blood pressure. Green tea might help in elderly people who have low blood pressure after eating.
  • Decreasing high levels of fat, like cholesterol and triglycerides, in the blood (hyperlipidemia).
  • Reducing abnormal development and growth of cells of the cervix (cervical dysplasia) caused by human papilloma virus (HPV) infection.

Possibly ineffective for...

  • Preventing colon cancer.

Insufficient evidence to rate effectiveness for...

  • Weight loss. Taking a specific green tea extract (EGCG) seems to help moderately overweight people lose weight. But green tea doesn’t help people keep the weight off.
  • High blood pressure. Some research shows that drinking green tea regularly seems to lower the chance of getting high blood pressure. But not all research agrees.
  • Stroke prevention. According to a large study done in Japan, drinking 3 cups of green tea per day seems to significantly lower the risk of having a stroke, compared to drinking one cup or no tea. Women seem to benefit more than men.
  • Weak bones (osteoporosis). Population research suggests that drinking green tea for 10 years is associated with stronger bones.
  • Type 2 diabetes. Drinking green tea may help prevent diabetes. Research suggests that Japanese adults who drink 6 or more cups per day of green tea have a 33% lower risk of developing type 2 diabetes compared to those who drink one cup per day or less. This is especially true for women.
  • Breast cancer. Green tea does not seem to prevent breast cancer in Asian populations. However, in Asian-American populations, some evidence suggests that drinking green tea might reduce the risk of developing breast cancer. Most research on green tea for breast cancer has been in Asian populations. The effect of green tea on breast cancer risk in Western populations is less clear.
  • Gum disease (gingivitis). Chewing candy that contains green tea extract seems to control plaque build-up on the teeth and reduce gum swelling.
  • Prostate cancer. Chinese men who drink more green tea seem to have a lower risk of developing prostate cancer. The more tea they drink, the more their risk drops.
  • Diarrhea.
  • Chronic fatigue syndrome (CFS).
  • Heart disease prevention.
  • Kidney stones.
  • Lung cancer.
  • Stomach cancer.
  • Skin cancer.
  • Dental cavities.
  • Cervical cancer.
  • Gastric cancer.
  • Leukemia.
  • Other conditions.
More evidence is needed to rate green tea for these uses.

How does it work?

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The useful parts of green tea are the leaf bud, leaf, and stem. Green tea is not fermented and is produced by steaming fresh leaves at high temperatures. During this process, it is able to maintain important molecules called polyphenols, which seem to be responsible for many of the benefits of green tea.

Polyphenols might be able to prevent inflammation and swelling, protect cartilage between the bones, and lessen joint degeneration. They also seem to be able to fight human papilloma virus (HPV) infections and reduce the growth of abnormal cells in the cervix (cervical dysplasia). Research cannot yet explain how this works.

Green tea contains 2% to 4% caffeine, which affects thinking and alertness, increases urine output, and may improve the function of brain messengers important in Parkinson’s disease. Caffeine is thought to stimulate the nervous system, heart, and muscles by increasing the release of certain chemicals in the brain called “neurotransmitters.”

Antioxidants and other substances in green tea might help protect the heart and blood vessels.

Are there safety concerns?

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Green tea is LIKELY SAFE for most adults. Green tea extract is POSSIBLY SAFE for most people for short-term use. In some people, green tea can cause stomach upset and constipation. Green tea extracts have been reported to cause liver problems in rare cases.

Too much green tea — more than five cups per day, for example — is POSSIBLY UNSAFE. It can cause side effects because of the caffeine. These side effects can range from mild to serious and include headache, nervousness, sleep problems, vomiting, diarrhea, irritability, irregular heartbeat, tremor, heartburn, dizziness, ringing in the ears, convulsions, and confusion. Green tea seems to reduce the absorption of iron from food. Drinking very high doses of green tea can actually be fatal. The fatal dose of caffeine in green tea is estimated to be 10-14 grams (150-200 mg per kilogram). Serious toxicity can occur at lower doses.

Caffeine is POSSIBLY SAFE in children in amounts commonly found in foods.

Green tea interacts with many medications, as explained below.

Special precautions & warnings:

Pregnancy and breast-feeding: If you are pregnant or breast-feeding, green tea in small amounts is POSSIBLY SAFE. Do not drink more than 2 cups a day of green tea. This amount of tea provides about 200 mg of caffeine. Consuming more than this amount has been linked to an increased risk of miscarriage and other negative effects. Caffeine passes into breast milk and can affect a nursing infant. Don’t drink an excessive amount of green tea if you are breast-feeding.

“Tired blood” (anemia): Drinking green tea may make anemia worse.

Anxiety disorders: The caffeine in green tea might make anxiety worse.

Bleeding disorders: Caffeine might increase the risk of bleeding. Don’t drink green tea if you have a bleeding disorder.

Heart conditions: Caffeine in green tea might cause irregular heartbeat.

Diabetes: Caffeine might affect blood sugar control. If you drink green tea and have diabetes, monitor your blood sugar carefully.

Diarrhea. Green tea contains caffeine. The caffeine in green tea, especially when taken in large amounts, can worsen diarrhea.

Irritable bowel syndrome (IBS): Green tea contains caffeine. The caffeine in green tea, especially when taken in large amounts, can worsen diarrhea and might worsen symptoms of IBS.

Glaucoma: Drinking green tea increases pressure inside the eye. The increase occurs within 30 minutes and lasts for at least 90 minutes.

High blood pressure: The caffeine in green tea might increase blood pressure in people with high blood pressure. However, this does not seem to occur in people who regularly drink green tea or other products that contain caffeine.

Liver disease: Green tea extract supplements have been linked to several cases of liver damage. Green tea extracts might make liver disease worse.

Weak bones (osteoporosis): Drinking green tea can increase the amount of calcium that is flushed out in the urine. Caffeine should be limited to less than 300 mg per day (approximately 2-3 cups of green tea). It is possible to make up for some calcium loss caused by caffeine by taking calcium supplements.

Are there interactions with medications?

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Major

Do not take this combination.

Amphetamines
Stimulant drugs such as amphetamines speed up the nervous system. By speeding up the nervous system, stimulant medications can make you feel jittery and increase your heart rate. The caffeine in green tea might also speed up the nervous system. Taking green tea along with stimulant drugs might cause serious problems including increased heart rate and high blood pressure. Avoid taking stimulant drugs along with caffeine.

Cocaine
Stimulant drugs such as cocaine speed up the nervous system. By speeding up the nervous system, stimulant medications can make you feel jittery and increase your heart rate. The caffeine in green tea might also speed up the nervous system. Taking green tea along with stimulant drugs might cause serious problems including increased heart rate and high blood pressure. Avoid taking stimulant drugs along with caffeine.

Ephedrine
Stimulant drugs speed up the nervous system. Caffeine (contained in green tea) and ephedrine are both stimulant drugs. Taking green tea along with ephedrine might cause too much stimulation and sometimes serious side effects and heart problems. Do not take caffeine-containing products and ephedrine at the same time.

Moderate

Be cautious with this combination.

Adenosine (Adenocard)
Green tea contains caffeine. The caffeine in green tea might block the effects of adenosine (Adenocard). Adenosine (Adenocard) is often used by doctors to do a test on the heart, called a cardiac stress test. Stop consuming green tea or other caffeine-containing products at least 24 hours before a cardiac stress test.

Antibiotics (Quinolone antibiotics)
The body breaks down caffeine to get rid of it. Some antibiotics might decrease how quickly the body breaks down caffeine. Taking these antibiotics along with green tea can increase the risk of side effects including jitteriness, headache, increased heart rate, and other side effects.

Some antibiotics that decrease how quickly the body breaks down caffeine include ciprofloxacin (Cipro), enoxacin (Penetrex), norfloxacin (Chibroxin, Noroxin), sparfloxacin (Zagam), trovafloxacin (Trovan), and grepafloxacin (Raxar).

Birth control pills (Contraceptive drugs)
The body breaks down the caffeine in green tea to get rid of it. Birth control pills can decrease how quickly the body breaks down caffeine. Taking green tea along with birth control pills can cause jitteriness, headache, fast heartbeat, and other side effects.

Some birth control pills include ethinyl estradiol and levonorgestrel (Triphasil), ethinyl estradiol and norethindrone (Ortho-Novum 1/35, Ortho-Novum 7/7/7), and others.

Bortezomib (Velcade)
Bortezomib (Velcade) is used in certain types of cancers. Green tea might interact with bortezomib (Velcade) and decrease its effectiveness for treating certain types of cancer. If you take bortezomib (Velcade) avoid taking green tea products.

Cimetidine (Tagamet)
Green tea contains caffeine. The body breaks down caffeine to get rid of it. Cimetidine (Tagamet) can decrease how quickly your body breaks down caffeine. Taking cimetidine (Tagamet) along with green tea might increase the chance of caffeine side effects including jitteriness, headache, fast heartbeat, and others.

Clozapine (Clozaril)
The body breaks down clozapine (Clozaril) to get rid of it. The caffeine in green tea seems to decrease how quickly the body breaks down clozapine (Clozaril). Taking green tea along with clozapine (Clozaril) can increase the effects and side effects of clozapine (Clozaril).

Dipyridamole (Persantine)
Green tea contains caffeine. The caffeine in green tea might block the affects of dipyridamole (Persantine). Dipyridamole (Persantine) is often used by doctors to do a test on the heart called a cardiac stress test. Stop drinking green tea or other caffeine-containing products at least 24 hours before a cardiac stress test.

Disulfiram (Antabuse)
The body breaks down caffeine to get rid of it. Disulfiram (Antabuse) can decrease how quickly the body gets rid of caffeine. Taking green tea (which contains caffeine) along with disulfiram (Antabuse) might increase the effects and side effects of caffeine, including jitteriness, hyperactivity, irritability, and others.

Estrogens
The body breaks down the caffeine in green tea to get rid of it. Estrogens can decrease how quickly the body breaks down caffeine. Taking estrogen pills and drinking green tea can cause jitteriness, headache, fast heartbeat, and other side effects. If you take estrogen pills, limit your caffeine intake.

Some estrogen pills include conjugated equine estrogens (Premarin), ethinyl estradiol, estradiol, and others.

Fluvoxamine (Luvox)
The body breaks down the caffeine in green tea to get rid of it. Fluvoxamine (Luvox) can decrease how quickly the body breaks down caffeine. Taking green tea along with fluvoxamine (Luvox) might cause too much caffeine in the body, and increase the effects and side effects of caffeine.

Lithium
Your body naturally gets rid of lithium. The caffeine in green tea can increase how quickly your body gets rid of lithium. If you take products that contain caffeine and you take lithium, stop taking caffeine products slowly. Stopping caffeine too quickly can increase the side effects of lithium.

Medications for asthma (Beta-adrenergic agonists)
Green tea contains caffeine. Caffeine can stimulate the heart. Some medications for asthma can also stimulate the heart. Taking caffeine with some medications for asthma might cause too much stimulation and cause heart problems.

Some medications for asthma include albuterol (Proventil, Ventolin, Volmax), metaproterenol (Alupent), terbutaline (Bricanyl, Brethine), and isoproterenol (Isuprel).

Medications that can harm the liver (Hepatotoxic drugs)
Green tea extracts might harm the liver. Taking green tea extracts along with medication that might also harm the liver can increase the risk of liver damage. Do not take green tea extracts if you are taking a medication that can harm the liver.

Some medications that can harm the liver include acetaminophen (Tylenol and others), amiodarone (Cordarone), carbamazepine (Tegretol), isoniazid (INH), methotrexate (Rheumatrex), methyldopa (Aldomet), fluconazole (Diflucan), itraconazole (Sporanox), erythromycin (Erythrocin, Ilosone, others), phenytoin (Dilantin) , lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), and many others.

Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)
Green tea might slow blood clotting. Taking green tea along with medications that also slow clotting might increase the chances of bruising and bleeding.

Some medications that slow blood clotting include ardeparin (Normiflo), aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), dipyridamole (Persantine), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid), warfarin (Coumadin), and others.

Medications used to treat cancer (Boronic acid-based proteasome inhibitors)
Green tea might interact with some medications used to treat cancer (boronic acid-based proteasome inhibitors). This might decrease its effectiveness of these medications for treating certain types of cancer. If you take one of these medications for cancer, avoid taking green tea products. Some of these drugs include bortezomib (Velcade).

Nicotine
Stimulant drugs such as nicotine speed up the nervous system. By speeding up the nervous system, stimulant medications can make you feel jittery and increase your heart rate. The caffeine in green tea might also speed up the nervous system. Taking green tea along with stimulant drugs might cause serious problems, including increased heart rate and high blood pressure. Avoid taking stimulant drugs along with caffeine.

Pentobarbital (Nembutal)
The stimulant effects of the caffeine in green tea can block the sleep-producing effects of pentobarbital (Nembutal).

Phenylpropanolamine
Green tea contains caffeine. Caffeine can stimulate the body. Phenylpropanolamine can also stimulate the body. Taking green tea and phenylpropanolamine together might cause too much stimulation and increase heartbeat, increase blood pressure, and cause nervousness.

Riluzole (Rilutek)
The body breaks down riluzole (Rilutek) to get rid of it. Drinking green tea can decrease how quickly the body breaks down riluzole (Rilutek) and increase the effects and side effects of riluzole.

Theophylline
Green tea contains caffeine. Caffeine works similarly to theophylline. Caffeine can also decrease how quickly the body gets rid of theophylline. Taking green tea along with theophylline might increase the effects and side effects of theophylline.

Verapamil (Calan, Covera, Isoptin, Verelan)
The body breaks down the caffeine in green tea to get rid of it. Verapamil (Calan, Covera, Isoptin, Verelan) can decrease how quickly the body gets rid of caffeine. Drinking green tea and taking verapamil (Calan, Covera, Isoptin, Verelan) can increase the risk of side effects for caffeine including jitteriness, headache, and an increased heartbeat.

Warfarin (Coumadin)
Warfarin (Coumadin) is used to slow blood clotting. Large amounts of green tea have been reported to decrease the effectiveness of warfarin (Coumadin). Decreasing the effectiveness of warfarin (Coumadin) might increase the risk of clotting. It is unclear why this interaction might occur. Be sure to have your blood checked regularly. The dose of your warfarin (Coumadin) might need to be changed.

Minor

Be watchful with this combination.

Alcohol
The body breaks down the caffeine in green tea to get rid of it. Alcohol can decrease how quickly the body breaks down caffeine. Taking green tea along with alcohol might cause too much caffeine in the bloodstream and caffeine side effects including jitteriness, headache, and fast heartbeat.

Fluconazole (Diflucan)
Green tea contains caffeine. The body breaks down caffeine to get rid of it. Fluconazole (Diflucan) might decrease how quickly the body gets rid of caffeine and cause caffeine to stay in the body too long. Taking fluconazole (Diflucan) along with green tea might increase the risk of side effects such as nervousness, anxiety, and insomnia.

Medications for diabetes (Antidiabetes drugs)
Green tea contains caffeine. There is conflicting evidence that caffeine might either increase or decrease blood sugar. Diabetes medications are used to lower blood sugar. Taking some medications for diabetes along with caffeine might decrease the effectiveness of diabetes medications. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.

Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.

Mexiletine (Mexitil)
Green tea contains caffeine. The body breaks down caffeine to get rid of it. Mexiletine (Mexitil) can decrease how quickly the body breaks down caffeine. Taking Mexiletine (Mexitil) along with green tea might increase the caffeine effects and side effects of green tea.

Terbinafine (Lamisil)
The body breaks down the caffeine in green tea to get rid of it. Terbinafine (Lamisil) can decrease how fast the body gets rid of caffeine. Taking green tea along with terbinafine (Lamisil) can increase the risk of caffeine side effects including jitteriness, headache, increased heartbeat, and other effects.

Are there interactions with herbs and supplements?

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Bitter orange
Bitter orange, used along with caffeine or caffeine-containing herbs such as green tea, can increase blood pressure and heart rate in otherwise healthy people. This might damage the heart and blood vessels.

Caffeine-containing herbs and supplements
Green tea contains caffeine. Using green tea along with other herbs and supplements that contain caffeine might increase the effects of caffeine, and also its unwanted side effects. Some natural products that contain caffeine include coffee, black tea, oolong tea, guarana, mate, cola, and others.

Creatine
There is some concern that combining caffeine, ephedra, and creatine might increase the risk of serious unwanted side effects. One athlete who used this combination, as well as some other supplements to improve his performance, suffered a stroke. Researchers worry the stroke might have been caused by the supplements.

Ephedra (Ma Huang)
Don't take green tea with ephedra. The caffeine in green tea might increase the effects of ephedra. Using ephedra with caffeine might increase the risk of serious life-threatening or disabling conditions such as hypertension, heart attack, stroke, seizures, and death.

Folic acid
There is some concern that green tea might decrease the activity of folic acid, leaving the body with less than the amount of folic acid it needs.

Herbs and supplements that might harm the liver
In several cases, people who took green tea developed liver damage. Researchers worry that the damage might have been linked to the green tea. Taking green tea extracts with other herbs or supplements that might harm the liver could increase the risk of harm to the liver. Other products that might adversely affect the liver include bishop's weed, borage, chaparral, uva ursi, and others.

Iron
Green tea might reduce the absorption of iron supplements. For most people, this effect will not be enough to make a difference in their health. But people who don't have enough iron in their system would be wise to drink green tea between meals rather than with meals to lessen this interaction.

Are there interactions with foods?

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Iron
Green tea appears to reduce absorption of iron from foods.

Milk
Adding milk to tea seems to reduce some of tea's benefits for the heart and blood vessels. Milk might bind and prevent absorption of the antioxidants in tea. But this is controversial. More research is needed to find out how important this interaction really is.

What dose is used?

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The following doses have been studied in scientific research:

AS A DRINK:
Doses of green tea vary significantly, but usually range between 1-10 cups daily. The commonly used dose of green tea is based on the amount typically consumed in Asian countries, which is about 3 cups per day, providing 240-320 mg of the active ingredients, polyphenols. To make tea, people typically use 1 teaspoon of tea leaves in 8 ounces boiling water.
  • For headache or restoring mental alertness: tea providing is up to 250 mg of caffeine per day, or approximately 3 cups of tea per day.
  • For improving thinking: tea providing 60 mg of caffeine, or approximately one cup.
  • For reducing cholesterol: drinking 10 or more cups per day has been associated with decreased cholesterol levels. Theaflavin-enriched green tea extract, 375 mg daily for 12 weeks, has also been used for lowering cholesterol.
  • For human papilloma virus (HPV) infections of the cervix: green tea extract, 200 mg daily alone or in combination with topical green tea ointment, for 8-12 weeks.
  • For preventing Parkinson’s disease:
    • Men consuming 421-2716 mg total caffeine (approximately 5-33 cups of green tea) daily have the lowest risk of developing Parkinson’s disease. However, a significantly lower risk is also associated with consumption of as little as 124-208 mg of caffeine (approximately 1-3 cups of green tea) daily.
    • In women: more moderate caffeine consumption seems to be best, equivalent to approximately 1-4 cups of green tea per day.
APPLIED TO THE SKIN:
  • For human papillomavirus (HPV) infections of the cervix: green tea ointment alone or in combination with oral green tea extract, twice weekly for 8-12 weeks.
  • For genital warts: a specific green tea extract ointment (Veregen, Bradley Pharmaceuticals) providing 15% kunecatechins applied three times daily to external warts for up to 16 weeks has been used.

Other names

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Camellia sinensis, Camellia thea, Camellia theifera, Constituant Polyphénolique de Thé Vert, CPTV, EGCG, Epigallo Catechin Gallate, Épigallo-Catéchine Gallate, Epigallocatechin Gallate, Extrait de Camellia Sinensis, Extrait de Thé, Extrait de Thé Vert, Extrait de Thea Sinensis, Green Sencha Tea, Green Tea Extract, Green Tea Polyphenolic Fraction, GTP, GTPF, Japanese Tea, Kunecatechins, Poly E, Polyphenon E, PTV, Té Verde, Tea, Tea Extract, Tea Green, Thé, Thé de Camillia, Thé Japonais, Thé Vert, Thé Vert de Yame, Thé Vert Sensha, Thea bohea, Thea sinensis, Thea viridis, Yame Green Tea, Yame Tea.

Methodology

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To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.methodology (http://www.nlm.nih.gov/medlineplus/druginfo/natural/methodology.html).

References

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To see all references for the Green tea page, please go to http://www.nlm.nih.gov/medlineplus/druginfo/natural/960.html.

  1. Golden ED, Lam PY, Kardosh A, et al. Green tea polyphenols block the anticancer effects of bortezomib and other boronic acid-based proteasome inhibitors. Blood 2009;113:5927-37.
  2. Phung OJ, Baker WL, Matthews LJ, et al. Effect of green tea catechins with or without caffeine on anthropometric measures: a systemic review and meta-analysis. Am J Clin Nutr 2010;91:73-81.
  3. Savitz DA, Chan RL, Herring AH, et al. Caffeine and miscarriage risk. Epidemiology 2008;19:55-62.
  4. Weng X, Odouli R, Li DK. Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study. Am J Obstet Gynecol 2008;198:279.e1-8.
  5. Kundu T, Dey S, Roy M, et al. Induction of apoptosis in human leukemia cells by black tea and its polyphenol theaflavin. Cancer Lett 2005;230:111-21.
  6. Liu S, Lu H, Zhao Q, et al. Theaflavin derivatives in black tea and catechin derivatives in green tea inhibit HIV-1 entry by targeting gp41. Biochim Biophys Acta 2005;1723:270-81.
  7. Yanagida A, Shoji A, Shibusawa Y, et al. Analytical separation of tea catechins and food-related polyphenols by high-speed counter-current chromatography. J Chromatogr A 2006;1112:195-201.
  8. Taubert D, Roesen R, Schomig E. Effect of cocoa and tea intake on blood pressure: a meta-analysis. Arch Intern Med 2007;167:626-34.
  9. Lorenz M, Jochmann N, von Krosigk A, et al. Addition of milk prevents vascular protective effects of tea. Eur Heart J 2007;28:219-23.
  10. Correa A, Stolley A, Liu Y. Prenatal tea consumption and risks of anencephaly and spina bifida. Ann Epidemiol 2000;10:476-7.
  1. Bradley Pharmaceuticals. Veregen Prescribing Information. October 2006.
  2. Katiyar SK, Mohan RR, Agarwal R, Mukhtar H. Protection against induction of mouse skin papillomas with low and high risk of conversion to malignancy by green tea polyphenols. Carcinogenesis 1997;18:497-502.
  3. Jimenez-Saenz M, Martinez-Sanchez, MDC. Acute hepatitis associated with the use of green tea infusions. J Hepatol 2006;44:616-9.
  4. Navarro-Peran E, Cabezas-Herrera J, Garcia-Canovas F, et al. The antifolate activity of tea catechins. Cancer Res 2005;65:2059-64.
  5. Isbrucker RA, Edwards JA, Wolz E, et al. Safety studies on epigallocatechin gallate (EGCG) preparations. Part 3: teratogenicity and reproductive toxicity studies in rats. Food Chem Toxicol 2006;44:651-61.
  6. Chu KO, Wang CC, Chu CY, et al. Pharmacokinetic studies of green tea catechins in maternal plasma and fetuses in rats. J Pharm Sci 2006;95:1372-81.
  7. Kuriyama S, Shimazu T, Ohmori K, et al. Green tea consumption and mortality due to cardiovascular disease, cancer, and all-cause mortality. JAMA 2006;296:1255-65.
  8. Wu AH, Tseng CC, Van Den Berg D, Yu MC. Tea intake, COMT genotype, and breast cancer in Asian-American women. Cancer Res 2003;63:7526-9.
  9. Yuan JM, Koh WP, Sun CL, et al. Green tea intake, ACE gene polymorphism and breast cancer risk among Chinese women in Singapore. Carcinogenesis 2005;26:1389-94.
  10. Donovan JL, Chavin KD, Devane CL, et al. Green tea (Camellia sinensis) extract does not alter cytochrome P450 3A4 or 2D6 activity in healthy volunteers. Drug Metab Dispos 2004;32:906-8.
  11. Kovacs EM, Lejeune MP, Nijs I, Westerterp-Plantenga MS. Effects of green tea on weight maintenance after body-weight loss. Br J Nutr 2004;91:431-7.
  12. Wu AH, Yu MC, Tseng CC, et al. Green tea and risk of breast cancer in Asian Americans. Int J Cancer 2003;106:574-9.
  13. Suzuki Y, Tsubono Y, Nakaya N, et al. Green tea and the risk of breast cancer: pooled analysis of two prospective studies in Japan. Br J Cancer 2004;90:1361-3.
  14. Iso H, Date C, Wakai K, et al; JACC Study Group. The relationship between green tea and total caffeine intake and risk for self-reported type 2 diabetes among Japanese adults. Ann Intern Med 2006;144:554-62.
  15. Gloro R, Hourmand-Ollivier I, Mosquet B, et al. Fulminant hepatitis during self-medication with hydroalcoholic extract of green tea. Eur J Gastroenterol Hepatol 2005;17:1135-7.
  16. Bonkovsky HL. Hepatotoxicity associated with supplements containing Chinese green tea (Camellia sinensis). Ann Intern Med 2006;144:68-71.
  17. Henning M, Fajardo-Lira C, Lee HW, et al. Catechin content of 18 teas and a green tea extract supplement correlates with the antioxidant capacity. Nutr Cancer 2003;45:226-35.
  18. Khokhar S, Magnusdottir SG. Total phenol, catechin, and caffeine contents of teas commonly consumed in the United kingdom. J Agric Food Chem 2002;50:565-70.
  19. Jian L, Xie LP, Lee AH, Binns CW. Protective effect of green tea against prostate cancer: a case-control study in southeast China. Int J Cancer 2004;108:130-5.
  20. 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.
  21. Robinson LE, Savani S, Battram DS, et al. Caffeine ingestion before an oral glucose tolerance test impairs blood glucose management in men with type 2 diabetes. J Nutr 2004;134:2528-33.
  22. Lake CR, Rosenberg DB, Gallant S, et al. Phenylpropanolamine increases plasma caffeine levels. Clin Pharmacol Ther 1990;47:675-85.
  23. Forrest WH Jr, Bellville JW, Brown BW Jr. The interaction of caffeine with pentobarbital as a nighttime hypnotic. Anesthesiology 1972;36:37-41.
  24. Raaska K, Raitasuo V, Laitila J, Neuvonen PJ. Effect of caffeine-containing versus decaffeinated coffee on serum clozapine concentrations in hospitalised patients. Basic Clin Pharmacol Toxicol 2004;94:13-8.
  25. Watson JM, Sherwin RS, Deary IJ, et al. Dissociation of augmented physiological, hormonal and cognitive responses to hypoglycaemia with sustained caffeine use. Clin Sci (Lond) 2003;104:447-54.
  26. Winkelmayer WC, Stampfer MJ, Willett WC, Curhan GC. Habitual caffeine intake and the risk of hypertension in women. JAMA 2005;294:2330-5.
  27. Juliano LM, Griffiths RR. A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology (Berl) 2004;176:1-29.
  28. Leson CL, McGuigan MA, Bryson SM. Caffeine overdose in an adolescent male. J Toxicol Clin Toxicol 1988;26:407-15.
  29. Benowitz NL, Osterloh J, Goldschlager N, et al. Massive catecholamine release from caffeine poisoning. JAMA 1982;248:1097-8.
  30. Acheson KJ, Gremaud G, Meirim I, et al. Metabolic effects of caffeine in humans: lipid oxidation or futile cycling? Am J Clin Nutr 2004;79:40-6.
  31. Scholey AB, Kennedy DO. Cognitive and physiological effects of an "energy drink:" an evaluation of the whole drink and of glucose, caffeine and herbal flavouring fractions. Psychopharmacology (Berl) 2004;176:320-30.
  32. Haller CA, Benowitz NL, Jacob P 3rd. Hemodynamic effects of ephedra-free weight-loss supplements in humans. Am J Med 2005;118:998-1003.
  33. Larsson SC, Wolk A. Tea consumption and ovarian cancer risk in a population-based cohort. Arch Intern Med 2005;165:2683-6.
  34. Schabath MB, Hernandez LM, Wu X, et al. Dietary phytoestrogens and lung cancer risk. JAMA 2005;294:1493-1504.
  35. Seely D, Mills EJ, Wu P, et al. The effects of green tea consumption on incidence of breast cancer and recurrence of breast cancer: a systematic review and meta-analysis. Integr Cancer Ther 2005;4:144-55.
  36. Son DJ, Cho MR, Jin YR, et al. Antiplatelet effect of green tea catechins: a possible mechanism through arachidonic acid pathway. Prostaglandins Leukot Essent Fatty Acids 2004;71:25-31.
  37. Choi JH, Chai YM, Joo GJ, et al. Effects of green tea catechin on polymorphonuclear leukocyte 5'-lipoxygenase activity, leukotriene B4 synthesis, and renal damage in diabetic rats. Ann Nutr Metab 2004;48:151-5.
  38. Mohseni H, Zaslau S, McFadden D, et al. COX-2 inhibition demonstrates potent anti-proliferative effects on bladder cancer in vitro. J Surg Res 2004;119:138-42 .
  39. Gupta S, Saha B, Giri AK. Comparative antimutagenic and anticlastogenic effects of green tea and black tea: a review. Mutat Res 2002;512:37-65.
  40. Yang YC, Lu FH, Wu JS, et al. The protective effect of habitual tea consumption on hypertension. Arch Intern Med 2004 26;164:1534-40.
  41. Haqqi TM, Anthony DD, Gupta S, et al. Prevention of collagen-induced arthritis in mice by a polyphenolic fraction from green tea. Proc Natl Acad Sci U S A 1999;96:4524-9.
  42. Adcocks C, Collin P, Buttle DJ. Catechins from green tea (Camellia sinensis) inhibit bovine and human cartilage proteoglycan and type II collagen degradation in vitro. J Nutr 2002;132:341-6.
  43. Ahmed S, Rahman A, Hasnain A, et al. Green tea polyphenol epigallocatechin-3-gallate inhibits the IL-1 beta-induced activity and expression of cyclooxygenase-2 and nitric oxide synthase-2 in human chondrocytes. Free Radic Biol Med 2002;33:1097-105.
  44. Petrie HJ, Chown SE, Belfie LM, et al. Caffeine ingestion increases the insulin response to an oral-glucose-tolerance test in obese men before and after weight loss. Am J Clin Nutr 2004;80:22-8.
  45. Lane JD, Barkauskas CE, Surwit RS, Feinglos MN. Caffeine impairs glucose metabolism in type 2 diabetes. Diabetes Care 2004;27:2047-8.
  46. Vinson JA, Teufel K, Wu N. Green and black teas inhibit atherosclerosis by lipid, antioxidant, and fibrinolytic mechanisms. J Agric Food Chem 2004;52:3661-5.
  47. Zheng G, Sayama K, Okubo T, et al. Anti-obesity effects of three major components of green tea, catechins, caffeine and theanine, in mice. In Vivo 2004;18:55-62.
  48. Sato J, Nakata H, Owada E, et al. Influence of usual intake of dietary caffeine on single-dose kinetics of theophylline in healthy human subjects. Eur J Clin Pharmacol 1993;44:295-8.
  49. Cannon ME, Cooke CT, McCarthy JS. Caffeine-induced cardiac arrhythmia: an unrecognised danger of healthfood products. Med J Aust 2001;174:520-1.
  50. Durrant KL. Known and hidden sources of caffeine in drug, food, and natural products. J Am Pharm Assoc 2002;42:625-37.
  51. Beach CA, Mays DC, Guiler RC, et al. Inhibition of elimination of caffeine by disulfiram in normal subjects and recovering alcoholics. Clin Pharmacol Ther 1986;39:265-70.
  52. Dews PB, O'Brien CP, Bergman J. Caffeine: behavioral effects of withdrawal and related issues. Food Chem Toxicol 2002;40:1257-61.
  53. Holmgren P, Norden-Pettersson L, Ahlner J. Caffeine fatalities--four case reports. Forensic Sci Int 2004;139:71-3.
  54. Chou T. Wake up and smell the coffee. Caffeine, coffee, and the medical consequences. West J Med 1992;157:544-53.
  55. Howell LL, Coffin VL, Spealman RD. Behavioral and physiological effects of xanthines in nonhuman primates. Psychopharmacology (Berl) 1997;129:1-14.
  56. Rakic V, Beilin LJ, Burke V. Effect of coffee and tea drinking on postprandial hypotension in older men and women. Clin Exp Pharmacol Physiol 1996;23:559-63.
  57. Heseltine D, Dakkak M, woodhouse K, et al. The effect of caffeine on postprandial hypotension in the elderly. J Am Geriatr Soc 1991;39:160-4.
  58. Castellanos FX, Rapoport JL. Effects of caffeine on development and behavior in infancy and childhood: a review of the published literature. Food Chem Toxicol 2002;40:1235-42.
  59. Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html.
  60. Zheng XM, Williams RC. Serum caffeine levels after 24-hour abstention: clinical implications on dipyridamole Tl myocardial perfusion imaging. J Nucl Med Technol 2002;30:123-7.
  61. Aqel RA, Zoghbi GJ, Trimm JR, et al. Effect of caffeine administered intravenously on intracoronary-administered adenosine-induced coronary hemodynamics in patients with coronary artery disease. Am J Cardiol 2004;93:343-6.
  62. Underwood DA. Which medications should be held before a pharmacologic or exercise stress test? Cleve Clin J Med 2002;69:449-50.
  63. Smith A. Effects of caffeine on human behavior. Food Chem Toxicol 2002;40:1243-55.
  64. Stanek EJ, Melko GP, Charland SL. Xanthine interference with dipyridamole-thallium-201 myocardial imaging. Pharmacother 1995;29:425-7.
  65. Carrillo JA, Benitez J. Clinically significant pharmacokinetic interactions between dietary caffeine and medications. Clin Pharmacokinet 2000;39:127-53.
  66. Wahllander A, Paumgartner G. Effect of ketoconazole and terbinafine on the pharmacokinetics of caffeine in healthy volunteers. Eur J Clin Pharmacol 1989;37:279-83.
  67. Sanderink GJ, Bournique B, Stevens J, et al. Involvement of human CYP1A isoenzymes in the metabolism and drug interactions of riluzole in vitro. Pharmacol Exp Ther 1997;282:1465-72.
  68. Brown NJ, Ryder D, Branch RA. A pharmacodynamic interaction between caffeine and phenylpropanolamine. Clin Pharmacol Ther 1991;50:363-71.
  69. May DC, Jarboe CH, VanBakel AB, Williams WM. Effects of cimetidine on caffeine disposition in smokers and nonsmokers. Clin Pharmacol Ther 1982;31:656-61.
  70. Nawrot P, Jordan S, Eastwood J, et al. Effects of caffeine on human health. Food Addit Contam 2003;20:1-30.
  71. Jatoi A, Ellison N, Burch PA, et al. A phase II trial of green tea in the treatment of patients with androgen independent metastatic prostate carcinoma. Cancer 2003;97:1442-6.
  72. Shirai T, Hayakawa H, Akiyama J, et al. Food allergy to green tea. J Allergy Clin Immunol 2003;112:805-6.
  73. Massey LK, Whiting SJ. Caffeine, urinary calcium, calcium metabolism and bone. J Nutr 1993;123:1611-4.
  74. Infante S, Baeza ML, Calvo M, et al. Anaphylaxis due to caffeine. Allergy 2003;58:681-2.
  75. 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.
  76. Kemberling JK, Hampton JA, Keck RW, et al. Inhibition of bladder tumor growth by the green tea derivative epigallocatechin-3-gallate. J Urol 2003;170:773-6.
  77. Maron DJ, Lu GP, Cai NS, et al. Cholesterol-lowering effect of a theaflavin-enriched green tea extract: a randomized controlled trial. Arch Intern Med 2003;163:1448-53.
  78. Nix D, Zelenitsky S, Symonds W, et al. The effect of fluconazole on the pharmacokinetics of caffeine in young and elderly subjects. Clin Pharmacol Ther 1992;51:183.
  79. Kockler DR, McCarthy MW, Lawson CL. Seizure activity and unresponsiveness after hydroxycut ingestion. Pharmacotherapy 2001;21:647-51.
  80. Grandjean AC, Reimers KJ, Bannick KE, Haven MC. The effect of caffeinated, non-caffeinated, caloric and non-caloric beverages on hydration. J Am Coll Nutr 2000;19:591-600.
  81. Dreher HM. The effect of caffeine reduction on sleep quality and well-being in persons with HIV. J Psychosom Res 2003;54:191-8.
  82. Massey LK. Is caffeine a risk factor for bone loss in the elderly? Am J Clin Nutr 2001;74:569-70.
  83. Nehlig A, Debry G. Consequences on the newborn of chronic maternal consumption of coffee during gestation and lactation: a review. J Am Coll Nutr 1994;13:6-21.
  84. McGowan JD, Altman RE, Kanto WP Jr. Neonatal withdrawal symptoms after chronic maternal ingestion of caffeine. South Med J 1988;81:1092-4.
  85. Bara AI, Barley EA. Caffeine for asthma. Cochrane Database Syst Rev 2001;4:CD001112.
  86. Bracken MB, Triche EW, Belanger K, et al. Association of maternal caffeine consumption with decrements in fetal growth. Am J Epidemiol 2003;157:456-66.
  87. Temme EH, Van Hoydonck PG. Tea consumption and iron status. Eur J Clin Nutr 2002;56:379-86.
  88. Leung LK, Su Y, Chen R, et al. Theaflavins in black tea and catechins in green tea are equally effective antioxidants. J Nutr 2001;131:2248-51.
  89. de Maat MP, Pijl H, Kluft C, Princen HM. Consumption of black and green tea had no effect on inflammation, haemostasis and endothelial markers in smoking healthy individuals. Eur J Clin Nutr 2000;54:757-63.
  90. Hodgson JM, Croft KD, Mori TA, et al. Regular ingestion of tea does not inhibit in vivo lipid peroxidation in humans. J Nutr 2002;132:55-8.
  91. Locher R, Emmanuele L, Suter PM, et al. Green tea polyphenols inhibit human vascular smooth muscle cell proliferation stimulated by native low-density lipoprotein. Eur J Pharmacol 2002;434:1-7.
  92. Zhang M, Binns CW, Lee AH. Tea consumption and ovarian cancer risk: a case-control study in China. Cancer Epidemiol Biomarkers Prev 2002;11:713-8.
  93. Yu GP, Hsieh CC. Risk factors for stomach cancer: a population-based case-control study in Shanghai. Cancer Causes Control 1991;2:169-74.
  94. Ji BT, Chow WH, Yang G, et al. The influence of cigarette smoking, alcohol, and green tea consumption on the risk of carcinoma of the cardia and distal stomach in Shanghai, China. Cancer 1996;77:2449-57.
  95. 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.
  96. Choi YT, Jung CH, Lee SR, et al. The green tea polyphenol (-)-epigallocatechin gallate attenuates beta-amyloid-induced neurotoxicity in cultured hippocampal neurons. Life Sci 2001;70:603-14.
  97. Tajima K, Tominaga S. Dietary habits and gastro-intestinal cancers: a comparative case-control study of stomach and large intestinal cancers in Nagoya, Japan. Jpn J Cancer Res 1985;76:705-16.
  98. Inoue M, Tajima K, Hirose K, et al. Tea and coffee consumption and the risk of digestive tract cancers: data from a comparative case-referent study in Japan. Cancer Causes Control 1998;9:209-16.
  99. Horner NK, Lampe JW. Potential mechanisms of diet therapy for fibrocystic breast conditions show inadequate evidence of effectiveness. J Am Diet Assoc 2000;100:1368-80.
  100. Zijp IM, Korver O, Tijburg LB. Effect of tea and other dietary factors on iron absorption. Crit Rev Food Sci Nutr 2000;40:371-98.
  101. Setiawan VW, Zhang ZF, Yu GP, et al. Protective effect of green tea on the risks of chronic gastritis and stomach cancer. Int J Cancer 2001;92:600-4.
  102. Bell DG, Jacobs I, Ellerington K. Effect of caffeine and ephedrine ingestion on anaerobic exercise performance. Med Sci Sports Exerc 2001;33:1399-403.
  103. Haller CA, Jacob P 3rd, Benowitz NL. Pharmacology of ephedra alkaloids and caffeine after single-dose dietary supplement use. Clin Pharmacol Ther 2002;71:421-32.
  104. Avisar R, Avisar E, Weinberger D. Effect of coffee consumption on intraocular pressure. Ann Pharmacother 2002;36:992-5.
  105. Peters U, Poole C, Arab L. Does tea affect cardiovascular disease? A meta-analysis. Am J Epidemiol 2001;154:495-503.
  106. Mukamal KJ, Maclure M, Muller JE, et al. Tea consumption and mortality after acute myocardial infarction. Circulation 2002;105:2476-81.
  107. Geleijnse JM, Launer LJ, van der Kuip DA, et al. Inverse association of tea and flavonoid intakes with incident myocardial infarction: the Rotterdam Study. Am J Clin Nutr 2002;75:880-6.
  108. Chung LY, Cheung TC, Kong SK, et al. Induction of apoptosis by green tea catechins in human prostate cancer DU145 cells. Life Sci 2001;68:1207-14.
  109. Pisters KM, Newman RA, Coldman B, et al. Phase I trial of oral green tea extract in adult patients with solid tumors. J Clin Oncol 2001;19:1830-8.
  110. Wu CH, Yang YC, Yao WJ, et al. Epidemiological evidence of increased bone mineral density in habitual tea drinkers. Arch Intern Med 2002;162:1001-6.
  111. Cronin JR. Green tea extract stokes thermogenesis: will it replace ephedra? Altern Comp Ther 2000;6:296-300.
  112. Chantre P, Lairon D. Recent findings of green tea extract AR25 (Exolise) and its activity for the treatment of obesity. Phytomedicine 2002;9:3-8.
  113. Shaw JC. Green tea polyphenols may be useful in the treatment of androgen-mediated skin disorders. Arch Dermatol 2001;137:664.
  114. Samman S, Sandstrom B, Toft MB, et al. Green tea or rosemary extract added to foods reduces nonheme-iron absorption. Am J Clin Nutr 2001;73:607-12.
  115. Ferrini RL, Barrett-Connor E. Caffeine intake and endogenous sex steroid levels in postmenopausal women. The Rancho Bernardo Study. Am J Epidemiol 1996:144:642-4.
  116. Ardlie NG, Glew G, Schultz BG, Schwartz CJ. Inhibition and reversal of platelet aggregation by methyl xanthines. Thromb Diath Haemorrh 1967;18:670-3.
  117. Ali M, Afzal M. A potent inhibitor of thrombin stimulated platelet thromboxane formation from unprocessed tea. Prostaglandins Leukot Med 1987;27:9-13.
  118. Sadzuka Y, Sugiyama T, Sonobe T. Efficacies of tea components on doxorubicin induced antitumor activity and reversal of multidrug resistance. Toxicol Lett 2000;114:155-62.
  119. Krahwinkel T, Willershausen B. The effect of sugar-free green tea chew candies on the degree of inflammation of the gingiva. Eur J Med Res 2000;5:463-7.
  120. Tsubono Y, Nishino Y, Komatsu S, et al. Green tea and the risk of gastric cancer in Japan. N Engl J Med 2001;344:632-6.
  121. Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000;343:1833-8.
  122. Imai K. Nakachi K. Cross-sectional study of effects of drinking green tea on cardiovascular and liver diseases. BMJ 1995;310:693-6.
  123. Sinclair CJ, Geiger JD. Caffeine use in sports. A pharmacological review. J Sports Med Phys Fitness 2000;40:71-9.
  124. Katiyar SK, Ahmad N, Mukhtar H. Green Tea and Skin. Arch Dermatol 2000;136:989-94.
  125. Hodgson JM, Puddey IB, Croft KD, et al. Acute effects of ingestion of black and green tea on lipoprotein oxidation. Am J Clin Nutr 2000;71:1103-7.
  126. Leenen R, Roodenburg AJ, Tijburg LB, et al. A single dose of tea with or without milk increases plasma antioxidant activity in humans. Eur J Clin Nutr 2000;54:87-92.
  127. Nemecz G. Green tea. US Pharm 2000;May:67-70.
  128. American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk (RE9403). Available at: http://aappolicy.aappublications.org/cgi/reprint/pediatrics;108/3/776.pdf.
  129. Lloyd T, Johnson-Rollings N, Eggli DF, et al. Bone status among postmenopausal women with different habitual caffeine intakes: a longitudinal investigation. J Am Coll Nutr 2000;19:256-61.
  130. Watson JM, Jenkins EJ, Hamilton P, et al. Influence of caffeine on the frequency and perception of hypoglycemia in free-living patients with type 1 diabetes. Diabetes Care 2000;23:455-9.
  131. Ross GW, Abbott RD, Petrovitch H, et al. Association of coffee and caffeine intake with the risk of parkinson disease. JAMA 2000;283:2674-9.
  132. Hagg S, Spigset O, Mjorndal T, Dahlqvist R. Effect of caffeine on clozapine pharmacokinetics in healthy volunteers. Br J Clin Pharmacol 2000;49:59-63.
  133. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid= 786bafc6f6343634fbf79fcdca7061e1&rgn=div5&view= text&node=21:3.0.1.1.13&idno=21
  134. Williams MH, Branch JD. Creatine supplementation and exercise performance: an update. J Am Coll Nutr 1998;17:216-34.
  135. Briggs GB, Freeman RK, Yaffe SJ. Drugs in Pregnancy and Lactation. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1998.
  136. Hindmarch I, Quinlan PT, Moore KL, Parkin C. The effects of black tea and other beverages on aspects of cognition and psychomotor performance. Psychopharmacol 1998;139:230-8.
  137. Durlach PJ. The effects of a low dose of caffeine on cognitive performance. Psychopharmacology (Berl) 1998;140:116-9.
  138. Kaegi E. Unconventional therapies for cancer: 2. Green tea. The Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. CMAJ 1998;158:1033-5.
  139. Lee IP, Kim YH, Kang MH, et al. Chemopreventive effect of green tea (Camellia sinensis) against cigarette smoke induced mutations in humans. J Cell Biochem Suppl 1997;27:68-75.
  140. 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.
  141. Klaunig JE, Xu Y, Han C, et al. The effect of tea consumption on oxidative stress in smokers and nonsmokers. Proc Soc Exp Biol Med 1999;220:249-54.
  142. Taylor JR, Wilt VM. Probable antagonism of warfarin by green tea. Ann Pharmacother 1999;33:426-8.
  143. Weisburger JH. Tea and health: the underlying mechanisms. Proc Soc Exp Biol Med 1999;220:271-5.
  144. Stammler G, Volm M. Green tea catechins (EGCG and EGC) have modulating effects on the activity of doxorubicin in drug-resistant cell lines. Anticancer Drugs 1997;8:265-8.
  145. Inoue M, Tajima K, Mizutani M, et al. Regular consumption of green tea and the risk of breast cancer recurrence: follow-up study from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC), Japan. Cancer Lett 2001;167:175-82.
  146. Kao YH, Hiipakka RA, Liao S. Modulation of endocrine systems and food intake by green tea epigallocatechin gallate. Endocrinology 2000;141:980-7.
  147. FDA. Proposed rule: dietary supplements containing ephedrine alkaloids. Available at: www.verity.fda.gov (Accessed 25 January 2000).
  148. Dews PB, Curtis GL, Hanford KJ, O'Brien CP. The frequency of caffeine withdrawal in a population-based survey and in a controlled, blinded pilot experiment. J Clin Pharmacol 1999;39:1221-32.
  149. Nurminen ML, Niittynen L, Korpela R, Vapaatalo H. Coffee, caffeine and blood pressure: a critical review. Eur J Clin Nutr 1999;53:831-9.
  150. DiPiro JT, Talbert RL, Yee GC, et al; eds. Pharmacotherapy: A pathophysiologic approach. 4th ed. Stamford, CT: Appleton & Lange, 1999.
  151. Migliardi JR, Armellino JJ, Friedman M, et al. Caffeine as an analgesic adjuvant in tension headache. Clin Pharmacol Ther 1994;56:576-86.
  152. Pollock BG, Wylie M, Stack JA, et al. Inhibition of caffeine metabolism by estrogen replacement therapy in postmenopausal women. J Clin Pharmacol 1999;39:936-40.
  153. Wemple RD, Lamb DR, McKeever KH. Caffeine vs caffeine-free sports drinks: effects on urine production at rest and during prolonged exercise. Int J Sports Med 1997;18:40-6.
  154. Stookey JD. The diuretic effects of alcohol and caffeine and total water intake misclassification. Eur J Epidemiol 1999;15:181-8.
  155. Fernandes O, Sabharwal M, Smiley T, et al. Moderate to heavy caffeine consumption during pregnancy and relationship to spontaneous abortion and abnormal fetal growth: a meta-analysis. Reprod Toxicol 1998;12:435-44.
  156. Eskenazi B. Caffeine—filtering the facts. N Engl J Med 1999;341:1688-9.
  157. Klebanoff MA, Levine RJ, DerSimonian R, et al. Maternal serum paraxanthine, a caffeine metabolite, and the risk of spontaneous abortion. N Engl J Med 1999;341:1639-44.
  158. The National Toxicology Program (NTP). Caffeine. Center for the Evaluation of Risks to Human Reproduction (CERHR). Available at: http://cerhr.niehs.nih.gov/common/caffeine.html.
  159. Rapuri PB, Gallagher JC, Kinyamu HK, Ryschon KL. Caffeine intake increases the rate of bone loss in elderly women and interacts with vitamin D receptor genotypes. Am J Clin Nutr 2001;74:694-700.
  160. Vandeberghe K, Gillis N, Van Leemputte M, et al. Caffeine counteracts the ergogenic action of muscle creatine loading. J Appl Physiol 1996;80:452-7.
  161. Wallach J. Interpretation of Diagnostic Tests. A synopsis of Laboratory Medicine. Fifth ed; Boston, MA: Little Brown, 1992.
  162. Graham HN. Green tea composition, consumption, and polyphenol chemistry. Prev Med 1992;21:334-50.
  163. Lou FQ, Zhang MF, Zhang XG, et al. A study on tea-pigment in prevention of atherosclerosis. Chin Med J (Engl) 1989;102:579-83.
  164. Booth SL, Madabushi HT, Davidson KW, et al. Tea and coffee brews are not dietary sources of vitamin K-1 (phylloquinone). J Am Diet Assoc 1995;95:82-3.
  165. Ohno Y, Aoki K, Obata K, et al. Case-control study of urinary bladder cancer in metropolitan Nagoya. Natl Cancer Inst Monogr 1985;69:229-34.
  166. Wakai K, Ohno Y, Obata K. Prognostic significance of selected lifestyle factors in urinary bladder cancer. Jpn J Cancer Res 1993;84:1223-9.
  167. Bushman JL. Green tea and cancer in humans: a review of the literature. Nutr Cancer 1998;31:151-9.
  168. L'Allemain G. [Multiple actions of EGCG, the main component of green tea]. Bull Cancer 1999;86:721-4.
  169. Cao Y, Cao R. Angiogenesis inhibited by drinking tea. Nature 1999;398:381.
  170. Garbisa S, Biggin S, Cavallarin N, et al. Tumor invasion: molecular shears blunted by green tea. Nat Med 1999;5:1216.
  171. Dulloo AG, Duret C, Rohrer D, et al. Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. Am J Clin Nutr 1999;70:1040-5.
  172. Hodgson JM, Puddey IB, Burke V, et al. Effects on blood pressure of drinking green and black tea. J Hypertens 1999;17:457-63.
  173. Wakabayashi K, Kono S, Shinchi K, et al. Habitual coffee consumption and blood pressure: A study of self-defense officials in Japan. Eur J Epidemiol 1998;14:669-73.
  174. 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.
  175. Vahedi K, Domingo V, Amarenco P, Bousser MG. Ischemic stroke in a sportsman who consumed MaHuang extract and creatine monohydrate for bodybuilding. J Neurol Neurosurg Psychiatr 2000;68:112-3.
  176. Joeres R, Klinker H, Heusler H, et al. Influence of mexiletine on caffeine elimination. Pharmacol Ther 1987;33:163-9.
  177. Ascherio A, Zhang SM, Hernan MA, et al. Prospective study of caffeine intake and risk of Parkinson's disease in men and women. Proceedings 125th Ann Mtg Am Neurological Assn. Boston, MA: 2000;Oct 15-18:42 (abstract 53).
  178. Mitscher LA, Mitscher LA, Jung M, Shankel D, et al. Chemoprotection: a review of the potential therapeutic antioxidant properties of green tea (Camellia sinensis) and certain of its constituents. Med Res Rev 1997;17:327-65.
  179. Merhav H, Amitai Y, Palti H, Godfrey S. Tea drinking and microcytic anemia in infants. Am J Clin Nutr 1985;41:1210-3.
  180. Jefferson JW. Lithium tremor and caffeine intake: two cases of drinking less and shaking more. J Clin Psychiatry 1988;49:72-3.
  181. Mester R, Toren P, Mizrachi I, et al. Caffeine withdrawal increases lithium blood levels. Biol Psychiatry 1995;37:348-50.
  182. Healy DP, Polk RE, Kanawati L, et al. Interaction between oral ciprofloxacin and caffeine in normal volunteers. Antimicrob Agents Chemother 1989;33:474-8.
  183. Carbo M, Segura J, De la Torre R, et al. Effect of quinolones on caffeine disposition. Clin Pharmacol Ther 1989;45:234-40.
  184. Harder S, Fuhr U, Staib AH, Wolff T. Ciprofloxacin-caffeine: a drug interaction established using in vivo and in vitro investigations. Am J Med 1989;87:89S-91S.
  185. Foster S, Duke JA. Eastern/Central Medicinal Plants. New York, NY: Houghton Mifflin Co., 1990.
  186. Hertog MGL, Sweetnam PM, Fehily AM, et al. Antioxidant flavonols and ischemic heart disease in a Welsh population of men: the Caerphilly Study. Am J Clin Nutr 1997;65:1489-94.
  187. Kubota K, Sakurai T, Nakazato K, et al. [Effect of green tea on iron absorption in elderly patients with iron deficiency anemia]. Nippon Ronen Igakkai Zasshi 1990;27:555-8.
  188. McKevoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
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