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Green Tea: Health Articles
Database - Green tea research has shown it has an effect on variety of health conditions. The ability to lower blood sugar, chelate iron and control the production of nitric oxide are all especially |
important. This ancient beverage seems custom-made to protect health and delay aging. To find how green tea benefits different organs and conditions click a specific topic from our article database below:
| - Anti-Bacterial - Anti-Inflammatory - Anti-Viral - Arthritis - Brain - Bowels - Cholesterol - Circulation - Diabetes |
- Eyes - Heart - Hypertension - Kidney - Liver - Psychological - Skin - Stroke - Teeth & Gums |
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Diabetes: General Date: 01-01-2010 |
Green tea has been used traditionally to control blood sugar in the body. Animal studies suggest that green tea may help prevent the development of type 1 diabetes and slow the progression once it has developed. People with type 1 diabetes produce little or no insulin, a hormone that converts glucose (sugar), starches, and other foods into energy needed for daily life. Green tea may help regulate glucose in the body. A few small clinical studies have found that daily supplementation of the diet with green tea extract powder lowered the hemoglobin A1c level in individuals with borderline diabetes.
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Coffee, green tea reduce diabetes risk: Study Date: 11-09-2009 |
Drinking caffeineated green tea and coffee could protect women and overweight men from type 2 (non-insulin dependent) diabetes.
Researchers from Japan analysed 17,413 men and women aged 40 to 65 years, who were free of diabetes at baseline. New cases of diabetes occurred in 231 men and 213 women over a 5-year follow up period, Health News reported.
Those who reported drinking six or more cups of green tea per day were 33 percent less likely to develop type 2 as compared to subjects who did not consume tea. Those who reported drinking three or more cups of coffee per day were 42 percent less likely to develop the condition than non-coffee drinkers. Drinking black Chinese tea did not appear to protect against type 2 diabetes.
The apparent protection was most pronounced in women and overweight men at higher risk for insulin resistance, a precursor to diabetes.
These findings from a Japanese population resemble results obtained in European and US populations in which people who drank seven or more cups of coffee per day had a 29 to 52 per cent reduced risk of diabetes as compared to those who drank fewer cups of coffee per day or none at all.
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Anti-Diabetic Properties of Green Tea Date: 01-01-2003 |
The ability to significantly lower blood glucose has been confirmed also in studies using diabetic rats. Both green and black tea possess anti-diabetic activity, and are effective in the prevention and treatment of diabetes. The fact that aged rats responded so dramatically to these polyphenols implies that it is possible to reverse the age-related rise in glucose intolerance and the resulting degenerative cascade of atherosclerosis and other degenerative disorders.
In what way are tea polyphenols able to lower serum glucose? The main mechanism seems to be the inhibition of the activity of starch digesting enzyme amylase. Tea inhibits both salivary and intestinal amylase, so that starch is broken down more slowly, and the rise in serum glucose is thus minimized. In addition, according to one recent study, tea may reduce the intestinal absorption of glucose.
A relatively little known compound found in onions and in tea, especially green tea, called diphenylamine, seems to have a strong sugar-lowering action. Again, the lesson here is that we are barely beginning to identify the significant phenolic compounds and their interactions; it's best not to rely on a single ingredient such as epigallocatechin gallate, but rather to ingest the whole complex set of bioactive compounds present in tea for best results.
Thanks to the serum glucose-lowering effect of tea, we thus obtain significant anti-aging benefits of calorie restriction, reduced glycation, and lower insulin secretion. If you drink tea with a carbohydrate-rich meal, you slow down the release of glucose and reduce its absorption (you also reduce the absorption of iron, another anti-aging benefit). Thus, you prevent the harmful spiking of insulin. Since insulin is our most fattening hormone and, with cortisol, our most pro-aging hormone, you also derive the substantial range of benefits that go with calorie restriction and insulin control.
Diabetics show premature aging and poor immune function due to the high oxidative stress that results from high serum glucose. When type-II diabetics were put on a diet that included 6 cups of tea a day plus some tomato sauce with onions, oxidative damage to the DNA of their lymphocytes was found to be markedly reduced. We already know that carotenoids can protect DNA; it is possible that compounds found in green tea may also be able to protect DNA, especially in synergistic action with other antioxidants.
Green tea has been used traditionally to control blood sugar in the body. Animal studies suggest that green tea may help prevent the development of type 1 diabetes and slow the progression once it has developed. People with type 1 diabetes produce little or no insulin, a hormone that converts glucose (sugar), starches, and other foods into energy needed for daily life. Green tea may help regulate glucose in the body.
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Anderson JW et al. Selective effects of different antioxidants on oxidation of
lipoproteins from rats. Proc Soc Exp Biol Med 1998;218:376-81.
Archives
of Dermatology, 2000;136:989-994, 1051.
Bravo L, Abia R et al. Degradation of polyphenols (catechin and tannic acid)
in the rat intestinal tract. Effect on colonic fermentation and fecal output.
Br J Nutr 1994;71:933-46.
Chan MM et al. Inhibition of inducible nitric oxide synthese gene expression
and enzyme activity by epigallocatechin gallate, a natural product from green
tea. Biochem Pharmacol 1997; 54:1281-86.
Chen ZY, Chan PT. Antioxidant activity of green tea catechins in canola oil.
Chem Phys Lipids 1996; 82:163-72.
Chen PC, et al. A green tea-derived polypheol, epigallocatechin-3-gallate, inhibits IkappaB kinase activation and IL-8 gene expression in respiratory epithelium. Inflammation 2002;26:233-41
Choi JH et al. Effects of green tea catechins on hepatic microsomal phospholipase.
J Nutr Sci Vitaminol 1998; 44:673-83.
Chung HY et al. Peroxynitrite-scavenging activity of green tea tannin. J Agric
Food Chem 1998; 46:4484-86.
Deng ZY, Tao BY, et al. Effect of green tea and black tea on blood glucose, triglycerides,
and antioxidants in aged rats. J Agricult Food Chem 1998;46:3875-78.
Dulloo AG, 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
Gomes A et al. Anti-hyperglycemic effect of black tea (Camellia sinensis) in
rat. J Ethnopharmacol 1995; 45: 223-26.
Graham HN. Green tea composition, consumption, and polyphenol chemistry. Prev Med 1992;21:334-50
Guo Q et al. Studies on protective mechanisms of four components of green tea
polyphenols against lipid peroxidation in synaptosomes. Biochim Biophys Acta
1996; 1304:210-22.
Haqqi, Tariq M., Antioxidants in green tea may prevent and reduce the severity
of rheumatoid arthritis, CWRU's School of Medicine study published in the April
13 issue of the Proceedings of the National
Hara Y., Academy of Sciences.Influence
of tea catechins on the digestive tract. J Cel Biochem 1997; Suppl 27: 52-58.
Hayashi M et al. Effects of green tea extract on galactosamine-induced hepatic
injury in rats. Nippon Yakurigaku Zasshi 1992; 100:391-99.
He YH, Kies C. Green and black tea consumption by humans: impact on polyphenol concentrations in feces, blood, and urine. Plant Foods Hum Nutr 1994; 46:221-9
Huang Y, Zhang AQ, et al. Vasorelaxant effects of purified green tea catechin
derivatives in rat mesenteric artery. Life Sciences 1998;63:275-283.
Imai K, Nakachi K. Cross-sectional study of effects of drinking green tea on
cardiovascular and liver diseases. BMJ 1995;310:693-96.
Kabuto H et al. Monoamine metabolites, iron induced seizures, and the anticonvulsant
effects of tannins. Neurochem Res 1992; 6:585-90.
Kaneko T, Matsuo M, Baba N. Inhibition of linoleic acid hydroperoxide-induced
toxicity in cultured human umbilical vein endothelial cells by catechins. Chem
Biol Interact 1998; 114:109-19.
Karawya Ms. Et al. Diphenylamine, an antihyperglycemic agent from onion and tea.
J Natural Prod 1984; 47:775-80.
Keli SO et al. Dietary flavonoids, antioxidant vitamins, and incidence of stroke:
the Zutphen study. Arch Intern Med 1995; 156:637-42.
Kooa, Marcel W.L. and Cho, Chi H. Corresponding Author Contact Information, Department of Pharmacology, Faculty of Medicine, The University of Hong Kong
Kreydiyyeh SI et al. Tea extract inhibits intestinal absorption of glucose and
sodium in rats. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 1994;108:359-65.
Lean ME et al. Dietary flavonols protect diabetic human lymphocytes against oxidative
damage to DNA. Diabetes 1999; 48:176-81.
Lin AM et al. The antioxidant property of green tea against iron-induced oxidative
stress in rat brain. Chin J Physiol 1998; 41:189-94.
Lin YL, Cheng CY, et al. Hypolipidemic effect of green tea leaves through induction
of antioxidant and phase II enzymes including superoxide dismutase, catalase,
and glutathione S-transferase in rats. J Agricult Food Chem 1998;46:1893-99.
Lin YL, Lin JK. Epigallocatechin gallate blocks the induction of nitric oxide
synthase by downregulating lipopolysaccharide-induced activity of transcription
factor nuclear factor-kappaB. Mol Pharmacol 1997; 52:465-72.
Lu LH, Lee SS, Huang HC. Epigallocatechin suppression of proliferation of vascular
smooth muscle cells: correlation with c-jun and JNK. Brit J Pharmacol 1998;124:1227-37.
Matsuoka Y et al. Ameliorative effects of tea catechins on active oxygen-related
nerve cell injuries. J Pharmacol Exp Ther 1995; 274:602-8.
Maron D, et al. Cholesterol-lowering effect of a theaflavin-enriched green tea extract: a randomized controlled trial. Arch Intern Med. 2003 Jun 23;163(12):1448-53.
Mazzio EA et al. Food constituents attenuate monoamine oxidase activity and peroxide
levels in C6 astrocyte cells. Planta Med 1998;64:603-6.
Nakane H, Ono K. Differential inhibition of HIV reverse transcriptase and various
DNA and RNA polymerases by some catechin derivatives. Nucleic Acids Symp Ser
1989; (21): 115-16.
Nakao M, Takio S, Ono K. Alkyl peroxyl radical scavenging activity of catechins.
Phytochemistry 1998;49:2379-82.
Okello, E. Phytotherapy Research, October 2004; vol 18: pp 624-627. News release,
University of Newcastle upon Tyne.
Pannala AS et al. Inhibition of peroxynitrite-mediated tyrosine nitration by
catechin polyphenols. Biochem Biophys Res Commun 1997; 232:164-68.
Omara-Otunn, Elizabeth, Retrieved February 11, 2009, The UConn Advance, University of Connecticut, February 2009.
Parshad R, Sanford RR, et al. Protective action of plant polyphenols on radiation-induced
chromatid breaks in cultured human cells. Anticancer Res 1998;18:3263-66.
Pricone, Nicholas Perricone, The Wrinkle Cure - The Perricone Prescription, Warner
Books; (May 2001).
Pietta P, Simonetti P. Dietary flavonoids and interactions with
endogenous antioxidants. Biochem Molec Biol International 1998;44:1069-74.
Plumb GW et al. Antioxidant properties of catechins and proanthocyanidins: effect
of polymerization, galloylation and glycosylation. Free Radic Res 1999; 29:351-58.
Quinlan P, Lane J, Aspinall L. Effects of hot tea, coffee and water ingestion
on physiological responses and mood: the role of caffeine, water, and beverage
type. Psychopharmacology 1997; 134:164-73.
Rasheed A, Haider M. Antibacterial activity of Camellia sinensis extracts against
dental caries. Arch Pharm Res 1998;21:348-52.
Sanaka S, Aizawa M, et al. Inhibitory effect of green tea polyphenols on growth
and adherence of an oral bacterium, Porphyromonas gingivalis. Biosci Biotechnol
Biochem 1996; 60:745-49.
Sato Y et al. Possible contribution of green tea drinking habits to the prevention
of stroke. Tohoku J Exp Med 1989; 157:337-43.
Serafini M et al. In vivo antioxidant effect of green and black tea in man. Eur
J Clin Nutr 1996;50:28-32.
Soliman KF, Mazzio EA. In vitro attenuation of nitric oxide production in C6
astrocyte cell culture by various dietary compounds. Proc Soc Exp Biol Med 1998;
218:390-97.
Takabayashi F, Harada N. Effects of green tea catechins on cerulein-induced acute
pancreatitis in rats. Pancreas 1997; 14:276-79.
Tao P. The inhibitory effects of catechin derivatives on the activities of human
immunodeficiency virus reverse transcriptase and DNA polymerases. Chung Kuo 1992;
14:334-38.
Taylor JR, Wilt VM. Probable antagonism of warfarin by green tea. Ann Pharmacother 1999;33:426-8.
Uchida S et al. Effect of epigallocatechin gallate on the life span of stroke-prone
spontaneously hypertensive rats. Clin Exp Pharmacol Physiol 1995; Suppl 1: S302-3.
Vinson JA, Dabbagh YA. Tea phenols: antioxidant effectiveness of teas, tea components,
tea fractions and their binding with lipoproteins. Nutr Res 1998; 18:1067-75.
Vinson JA, Dabbagh YA. Effect of green and black tea supplementation on lipids,
lipid oxidation and fibrinogen in the hamster: mechanisms for the epidemiological
benefits of tea drinking. FEBS Let 1998;433:44-46.
Wang H, Wu Y. Inhibitory effect of Chinese tea on N-nitrosation in vitro and
in vivo. IARC Sci Publ 1991; 105:546-49.
Yang YC, et al.The protective effect of habitual tea consumption on hypertension. Arch Intern Med. 2004 Jul 26;164(14):1534-40.
Yang FJ et al. Green tea polyphenols block endotoxin-induced tumor necrosis factor
alpha production and lethality in murine model. J Nutr 1998; 128:2334-40.
Yang TT, Koo MW. Hypocholesterolemic effects of Chinese tea. Pharmacol Res 1997;
35:505-12.
Yokogoshi H et al. Effect of theanine, r-glutamylethylamide, on brain monoamines
and striatal dopamine release in conscious rats. Neurochem Res 1998; 23:667-73.
Yokozawa T et al. In vivo and in vitro studies on the radical scavenging activity
of tea. J Agric Food Chem 1998; 46:2143-50.
You S. Study on feasibility of Chinese green tea polyphenols for preventing dental
caries. Chung Hua Kou Chiang 1993; 28:197-9.
Zhang J, Kashket S. Inhibition of salivary amylase by black and green teas and
their effects on the intraoral hydrolysis of starch. Caries Res 1998: 32:233-38.
Zhao BL et al. Scavenging effect of extracts of green tea and natural antioxidants
on active oxygen species. Cell Biophys 1989; 14:175-85.
