FDA rejects health claim for green tea

[Samuel]

http://www.cnn.com/2006/HEALTH/diet.fitness/05/10/green.tea.fda.ap/index.html

FDA rejects health claim for green tea

Wednesday, May 10, 2006; Posted: 9:41 a.m. EDT (13:41 GMT)

WASHINGTON (AP) -- There is no credible scientific evidence that drinking green tea reduces the risk of heart disease, federal regulators said Tuesday in rejecting a petition that sought to allow tea labels to make that claim.

The Food and Drug Administration said it reviewed 105 articles and other publications submitted as part of the petition but could find no evidence to support claims of the beverage's health benefits.

"FDA concludes there is no credible evidence to support qualified health claims for green tea or green tea extract and a reduction of a number of risk factors associated with CVD" or cardiovascular disease, Barbara O. Schneeman, director of the agency's Office of Nutritional Products, Labeling and Dietary Supplements, wrote in a letter denying the petition. The FDA posted the letter to its Web site Tuesday.

Ito En Ltd., a Japanese company that bills itself as the world's largest green tea company, and its U.S. subsidiary, Ito En (North America) Inc., petitioned the FDA in June 2005, seeking to make the claim that drinking at least five ounces of green tea a day may reduce the risk of heart disease.

A message left for a spokesman for Ito En (North America) Inc. was not immediately returned late Tuesday. A message left for the AAC Consulting Group, a Rockville, Maryland company that filed the actual petition, also was not immediately returned.

Green tea is brewed from the leaves of Camellia sinensis, also known as Thea sinensis. Unlike black and oolong tea, green tea is made from unfermented tea leaves.

The FDA previously has said that green tea likely does not reduce breast, prostate or any other type of cancer risk.

Nonetheless, the belief that drinking green tea confers health benefits has driven its popularity over the last decade, the Tea Association of the United States has said.

A health claim, in the language of the FDA, characterizes the relationship between a substance and a reduction in the risk of contracting a particular disease.

Copyright 2006 The Associated Press. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.

[Turtle2003]

But if one of the Drug Lords had a patent on green tea you can bet your *** that the FDA would swoon with joy over its effects. What a racket.

[kebaldwin]

I posted this article over in General Health or Supplements -- my favorite part was this:

The Food and Drug Administration said it reviewed 105 articles and other publications submitted as part of the petition but could find no evidence to support claims of the beverage's health benefits

I'm willing to bet that the tea industry picked 105 of the best articles showing undisputable evidence of the positive benefits of tea -- but yet the FDA found "no evidence"?

I can't wait to hear the true story. It takes a couple of months for LEF and others to give us the true story -- like who specifically was on this FDA panel and what drug companies they are receiving $50,000, or more, from.

[ThomasCGT]

Disadvantages of green tea (GT) are that it is high in naturally occurring aluminium and fluoride. In fact GT has the highest fluoride content of any plant. However, fluoride and aluminium free GT is available. GT is drunk in Japan almost on a daily basis, yet the cancer incidence in Japan today is extreme. GT is not a big deal The FDA approves Vioxx, chemos, aspartame etc so the FDA is also not a big deal. Make up your own mind and follow it, (before you get chipped and controlled). For heart disease its B6, B12 and folic acid to reduce homocysteine, vitamin C to reduce lipoprotein alpha, and cutting out sugar alcohol and reducing carbs for the tri glycerides. If the arteries are already narrowed its EDTA to clean them out. Green tea is not in the formuala. Surprising that people on this learned forum still mumble 'bout cholesterol and animal fats re heart disease..

[Angeline]

Japan also had a couple of nukes dropped on them. Sometimes we tend to focus too much on food and forget that we don't live in a pristine environment.

[lnrpoole]

My response is this: if the FDA approves it I stay away from it...If the FDA sends in their troops to squash (said item) then I'll take it..
That goes for Green Tea as well as Stevia, because I've discovered, a little late in life, but discovered it nonetheless, that the FDA is not our friend. They make Hitler look mild with their experiments on us, the public.

[Scars]

I don't think green tea is without benefits. Even if you were to look at it in a way that more green tea = less pop/other caloric drinks - this is still a substantial benefit.

Green tea makers are allowed to use this claim, however.

"Two studies do not show that drinking green tea reduces the risk of breast cancer in women, but one weaker, more limited study suggested that drinking green tea may reduce this risk."

Not exactly a glowing testimony.

It appears that green tea can lower the risk of breast cancer in women with a less-active version of a certain enzyme (1) - but this goes for most other antioxidant vitamins and phytochemical.

We have to remember here that the FDA is only disallowing a certain claim for one health aspect - it doesn't mean it possesses no health benefit.

(1) Cancer research 63: 7526, 2003

[Scars]

Disadvantages of green tea (GT) are that it is high in naturally occurring aluminium and fluoride. In fact GT has the highest fluoride content of any plant. However, fluoride and aluminium free GT is available. GT is drunk in Japan almost on a daily basis, yet the cancer incidence in Japan today is extreme. GT is not a big deal The FDA approves Vioxx, chemos, aspartame etc so the FDA is also not a big deal. Make up your own mind and follow it, (before you get chipped and controlled). For heart disease its B6, B12 and folic acid to reduce homocysteine, vitamin C to reduce lipoprotein alpha, and cutting out sugar alcohol and reducing carbs for the tri glycerides. If the arteries are already narrowed its EDTA to clean them out. Green tea is not in the formuala. Surprising that people on this learned forum still mumble 'bout cholesterol and animal fats re heart disease..

What do you mean by "extreme" in reference to the incidence of cancer in Japan?

The Fluoride and Aluminum content of the tea depends on the maturity of the leaf. The more mature, the higher the content. To date, there is nothing to convince me that the extremely improbable and theoretical risks of drinking tea outweigh the potentially wonderful benefits.

[Whoa182]

The FDA said that there was NO evidence that green tea in anyway slowed down or prevented cancer.

A few weeks later studies in humans showed that it was benificial in prostate cancer and CLL

http://news.bbc.co.uk/2/hi/health/4551748.stm

It's always been the same though, conflicting results. Just drink green tea!

I get equivilant of 10 cups a day :)

[Scars]

Inrpool,

Enjoy your BSE-infected beef... oh, and by the way - some may disagree with you on the Hitler thing...

[ThomasCGT]

Arent you doing a flip-flop, Scars. On the aspartame forum you knock alternatives, yet here you support green tea. By extreme cancer I refer to the true situation on the ground in Japan, not what the better-results-BS that Cancer Societies mumble about. Every single relative and every known friend of my Japanese wife that has died in the last 15 years, have succummbed to cancer. Anecdotal, but interesting. So where was the daily-drunk green tea protection? Cancer has causes that cannot be eliminated by immune boosting. Green tea wont kill the fascilopsis buskii parasite that releases OPT, nor will it detox the heavy metals, dyes, aflotoxins, alcohol, smoke particles. It will not kill the bacteria, nor will it increase the cholesterol that protects the cell membranes. Those are the causes, about which we should be kept in the dark. Is that right Scars? Or maybe the idiot PHds such as Hulda Clark and Marijah McCain to whom you refer in your aspartame forum are all wrong about curing cancer, and aspartame, microwaves etc, and the FDA and Big Pharma are correct.

[kebaldwin]

There are many bad things that happen to our body that cause oxidation and other damage. Then there are vitamins, minerals, and anti-oxidants that stop and reverse the damage and remove bad things from our bodies.

One can design a study to prove any pre conceived notion.

It would be wrong to say that someone eating high glycemic foods, smoking, drinking heavy, and doing drugs -- would benefit from sipping a couple of cups of green tea. It would be a peeble in the ocean.

But for someone to clean up their life, start taking their health seriously -- I think green tea has been shown through enough studies to promote a positive effect on total health.

The Food and Drug Administration said it reviewed 105 articles and other publications submitted as part of the petition but could find no evidence to support claims of the beverage's health benefits

I don't see how the FDA could discredit all 105 articles. I could see that maybe they discredited 33%, perhaps 50% -- but all 105? To say that tea has no health benefits? Something is very wrong at the FDA.

The only thing that the FDA will approve are "cut or prescribe" remedies where they, or their customers (AMA or pharma companies), make money.

[Scars]

The FDA said that there was NO evidence that green tea in anyway slowed down or prevented cancer.

A few weeks later studies in humans showed that it was benificial in prostate cancer and CLL

http://news.bbc.co.uk/2/hi/health/4551748.stm

It's always been the same though, conflicting results. Just drink green tea!

I get equivilant of 10 cups a day :)

Thanks for posting this, whoa - very relevant... one question for you - how many trips to the bathroom do you take per day :)

[Scars]

Arent you doing a flip-flop, Scars. On the aspartame forum you knock alternatives, yet here you support green tea. By extreme cancer I refer to the true situation on the ground in Japan, not what the better-results-BS that Cancer Societies mumble about. Every single relative and every known friend of my Japanese wife that has died in the last 15 years, have succummbed to cancer. Anecdotal, but interesting. So where was the daily-drunk green tea protection? Cancer has causes that cannot be eliminated by immune boosting. Green tea wont kill the fascilopsis buskii parasite that releases OPT, nor will it detox the heavy metals, dyes, aflotoxins, alcohol, smoke particles. It will not kill the bacteria, nor will it increase the cholesterol that protects the cell membranes. Those are the causes, about which we should be kept in the dark. Is that right Scars? Or maybe the idiot PHds such as Hulda Clark and Marijah McCain to whom you refer in your aspartame forum are all wrong about curing cancer, and aspartame, microwaves etc, and the FDA and Big Pharma are correct.


Interesting remark, Tom (do you mind if I call you Tom?). This may surprise you, but I don't categorically support one "realm" of medicine vs. the other - I would hope to believe that others don't either. Thank you for admitting your case for Japanese and cancer incidence as being anecdotal. If you can show me some credible evidence of the cancer rates in Japan - please post it. Again, just like the aspartame debate - the jury is still out with regards to the extent of the protective effects of GT. Through the research I've read - it would appear that it is more than biologically plausible (contrary to what you think) that it has anti-carcinogenic properties. There are far more causes and complexities to the multitude of disease known as cancer then what you just mentioned. Even if GT doesn't impact any one of the factors you mentioned, there are scads more biochemical pathways in which green tea, its polyphenols, and more specifically its EGCG could be chemo-preventitive. Like I said in my previous post, research seems to point towards it helping those with a certain gene interaction. Bottom line - you have nothing to lose and potentially much to gain by drinking green tea.

[kebaldwin]

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

2. 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.

3. 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.

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

5. 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.

6. 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.

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

8. 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.

9. 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.

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

11. 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.

12. Yang CS, Lee MJ, Chen L, Yang GY. Polyphenols as inhibitors of carcinogenesis. Environ Health Perspect 1997;105(Suppl 4):971–6 [review].

13. Menon LG, Kuttan R, Kuttan G. Anti-metastatic activity of curcumin and catechin. Cancer Lett 1999;141:159–65.

14. Mukhtar H, Ahmad N. Green tea in chemoprevention of cancer. Toxicol Sci 1999;52(2 Suppl):111–7.

15. Katiyar SK, Mukhtar H. Tea consumption and cancer. World Rev Nutr Diet 1996;79:154–84 [review].

16. Kohlmeier L, Weterings KG, Steck S, Kok FJ. Tea and cancer prevention: an evaluation of the epidemiologic literature. Nutr Cancer 1997;27:1–13 [review].

17. Tsubono Y, Nishino Y, Komatsu S, et al. Green tea and the risk of gastric cancer in Japan. New Engl J Med 2001;344:632–6.

18. Galanis DJ, Kolonel LN, Lee J, Nomura A. Intakes of selected foods and beverages and the incidence of gastric cancer among the Japanese residents of Hawaii: a prospective study. Int J Epidemiol 1998;27:173–80.

19. 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.

20. Otake S, Makimura M, Kuroki T, et al. Anticaries effects of polyphenolic compounds from Japanese green tea. Caries Res 1991;25:438–43.

21. Ooshima T, Minami T, Aono W, et al. Reduction of dental plaque deposition in humans by oolong tea extract. Caries Res 1994;28:146–9.

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

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

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

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

26. Goto K, Kanaya S, Nishikawa T, et al. The influence of tea catechins on fecal flora of elderly residents in long-term care facilities. Ann Long-Term Care 1998;6:43–8.

27. Goto K, Kanaya S, Ishigami T, Hara Y. The effects of tea catechins on fecal conditions of elderly residents in a long-term care facility. J Nutr Sci Vitaminol 1999;45:135–41.

28. 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.

29. Murray MT. The Healing Power of Herbs. Rocklin, CA: Prima Publishing, 1995, 192–6.

30. Imai K, Suga K, Nakachi K. Cancer-preventive effects of drinking green tea among a Japanese population. Prev Med 1997;26:769–75.

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

32. 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.

[kebaldwin]

Green tea constituent epigallocatechin-3-gallate and induction of apoptosis and cell cycle arrest in human carcinoma cells.

J Natl Cancer Inst, 89(24):1881-6 1997 Dec 17

BACKGROUND AND PURPOSE: The polyphenolic compounds present in green tea show cancer chemopreventive effects in many animal tumor models. Epidemiologic studies have also suggested that green tea consumption might be effective in the prevention of certain human cancers. We investigated the effect of green tea polyphenols and the major constituent, epigallocatechin-3-gallate, on the induction of apoptosis (programmed cell death) and regulation of cell cycle in human and mouse carcinoma cells. METHODS: Human epidermoid carcinoma cells (cell line A431), human carcinoma keratinocyte (cell line HaCaT), human prostate carcinoma cells (cell line DU145), mouse lymphoma cells (cell line L5178Y), and normal human epidermal keratinocytes (NHEKs) were used. Apoptosis was assessed by 1) the formation of internucleosomal DNA fragments by agarose gel electrophoresis, 2) confocal microscopy, and 3) flow cytometry after tagging the DNA fragments by fluorescence label. The distribution of cells in different phases of the cell cycle was analyzed by flow cytometry. RESULTS: Treatment of A431 cells with green tea polyphenols and its components, epigallocatechin-3-gallate, epigallocatechin, and epicatechin-3-gallate, resulted in the formation of internucleosomal DNA fragments, characteristic of apoptosis. Treatment with epigallocatechin-3-gallate also resulted in apoptosis in HaCaT, L5178Y, and DU145 cells, but not in NHEK. Confocal microscopy and flow cytometry confirmed the findings. The DNA cell cycle analysis showed that in A431 cells, epigallocatechin-3-gallate treatment resulted in arrest in the G0-G1 phase of the cell cycle and a dose-dependent apoptosis. CONCLUSIONS: Green tea may protect against cancer by causing cell cycle arrest and inducing apoptosis. It needs to be evaluated in human trials.


--------------------------------------------------------------------------------

Cross sectional study of effects of drinking green tea on cardiovascular and liver diseases [see comments]

BMJ, 310(6981):693-6 1995 Mar 18

OBJECTIVE--To investigate the association between consumption of green tea and various serum markers in a Japanese population, with special reference to preventive effects of green tea against cardiovascular disease and disorders of the liver. DESIGN--Cross sectional study. SETTING--Yoshimi, Japan. SUBJECTS--1371 men aged over 40 years resident in Yoshimi and surveyed on their living habits including daily consumption of green tea. Their peripheral blood samples were subjected to several biochemical assays. RESULTS--Increased consumption of green tea was associated with decreased serum concentrations of total cholesterol (P for trend < 0.001) and triglyceride (P for trend = 0.02) and an increased proportion of high density lipoprotein cholesterol together with a decreased proportion of low and very low lipoprotein cholesterols (P for trend = 0.02), which resulted in a decreased atherogenic index (P for trend = 0.02). Moreover, increased consumption of green tea, especially more than 10 cups a day, was related to decreased concentrations of hepatological markers in serum, aspartate aminotransferase (P for trend = 0.06), alanine transferase (P for trend = 0.07), and ferritin (P for trend = 0.02). CONCLUSION--The inverse association between consumption of green tea and various serum markers shows that green tea may act protectively against cardiovascular disease and disorders of the liver.


--------------------------------------------------------------------------------

Green tea consumption and the risk of pancreatic and colorectal cancers.

Int J Cancer, 310(6981):255-8 1997 Jan 27

The effect of green tea drinking in reducing human cancer risk is unclear, though a protective effect has been reported in numerous animal studies and several epidemiologic investigations. Herein the hypothesis that green tea consumption may reduce the risk of cancers of the colon, rectum and pancreas is examined in a large population-based case-control study conducted in Shanghai, China. Newly diagnosed cancer cases (931 colon, 884 rectum and 451 pancreas) during 1990-1993 among residents 30-74 years of age were included. Controls (n = 1,552) were selected among Shanghai residents and frequency-matched to cases by gender and age. Multivariate odds ratios (ORs) and 95% confidence intervals (CIs) of each cancer associated with green tea consumption were derived after adjustment for age, income, education and cigarette smoking. Additional adjustment for dietary items and body size was found to have minimal impact. An inverse association with each cancer was observed with increasing amount of green tea consumption, with the strongest trends for rectal and pancreatic cancers. For men, compared with non-regular tea drinkers, ORs among those in the highest tea consumption category ( or = 300 g/month) were 0.82 for colon cancer, 0.72 for rectal cancer and 0.63 for pancreatic cancer, with p values for trend being 0.38, 0.04 and 0.04, respectively. For women, the respective ORs for the highest consumption category ( or = 200 g/month) were 0.67, 0.57 and 0.53, with the respective p values for trend being 0.07, 0.001 and 0.008. Our findings provide further evidence that green tea drinking may lower the risk of colorectal and pancreatic cancers.


--------------------------------------------------------------------------------

Induction of apoptosis in prostate cancer cell lines by the green tea component, (-)-epigallocatechin-3-gallate.

Cancer Lett, 130(1-2):1-7 1998 Aug 14

Green tea components exert many biological effects, including antitumor and cancer preventive activities. In the search for anticancer agents for prostate cancer the inhibitory effects of green tea components were tested on the prostate cancer cell lines LNCaP, PC-3 and DU145. (-)-Epigallocatechin-3-gallate (EGCG) proved to be the most potent catechin at inhibiting cell growth. The inhibition induced by EGCG was found to occur via apoptotic cell death as shown by changes in nuclear morphology and DNA fragmentation. Thus, we report the first evidence that EGCG is the active component in green tea and induces apoptosis in human prostate cancer cells.


--------------------------------------------------------------------------------

Chemopreventive effect of green tea (Camellia sinensis) against cigarette smoke-induced mutations (SCE) in humans.

J Cell Biochem Suppl, 130():68-75 1997

Green tea (Camellia sinensis) is consumed daily between the meals or after meals in Japan and other Asian countries. In recent years, green tea and its major polyphenolics have been demonstrated to prevent chemically induced tumors in a variety of experimental animal models system. The exact mechanism(s) of its anticarcinogenic activity remains to be elucidated, but green tea polyphenolics have demonstrated antimutagenic, anticarcinogenic, antioxidant, and antipromotional effects, including inhibition of Phase I and inducing Phase II enzymes. Enzyme activities of glutathione peroxidase, catalase, and quinone reductase, and glutathione S-transferase are also induced. However, a paucity of green tea effects in humans prompted us to investigate antimutagenic effects of green tea against smoke-induced mutation in humans. Chemopreventive effects of green tea and coffee among cigarette smokers were examined in 52 clinically healthy male subjects between 20-51 years of age. Blood specimens were obtained from non-smokers (Group I), smokers (II), smokers consuming green tea (III), and smoker/coffee drinkers (IV). The mean years of cigarette smoking ( 10 cigarettes/day) of Groups II, III, and IV ranged from 13.4-14.7 years. Daily intake of green tea and coffee was 3 cups/day/6 months (III and IV). The frequencies of sister-chromatid exchange (SCE) in mitogen-stimulated peripheral lymphocytes from each experimental group were determined and statistically analyzed. SCE rates were significantly elevated in smokers (9.46 +/- 0.46) vs. non-smokers (7.03 +/- 0.33); however, the frequency of SCE in smokers who consumed green tea (7.94 +/- 0.31) was comparable to that of non-smokers, implying that green tea can block the cigarette-induced increase in SCE frequency. Coffee, by contrast, did not exhibit a significant inhibitory effect on smoking-induced SCE.


--------------------------------------------------------------------------------

Influence of drinking green tea on breast cancer malignancy among Japanese patients.

Jpn J Cancer Res, 89(3):254-61 1998 Mar

Inhibitory effects of green tea on carcinogenesis have been investigated in numerous laboratory studies using (-)-epigallocatechin gallate (EGCG) or crude green tea extract, and there is also some epidemiologic evidence. Further, EGCG has been reported to inhibit the growth of cancer cells, lung metastasis in an animal model, and urokinase activity. In this study, we first examined the association between consumption of green tea prior to clinical cancer onset and various clinical parameters assessed at surgery among 472 patients with stage I, II, and III breast cancer. We found that increased consumption of green tea was closely associated with decreased numbers of axillary lymph node metastases among premenopausal patients with stage I and II breast cancer and with increased expression of progesterone receptor (PgR) and estrogen receptor (ER) among postmenopausal ones. Since these are potential prognostic factors, we then investigated the prognosis of breast cancer with special reference to consumption of green tea, in a follow-up study of these patients. We found that increased consumption of green tea was correlated with decreased recurrence of stage I and II breast cancer (P <0.05 for crude disease-free survival); the recurrence rate was 16.7 or 24.3% among those consuming > < 0.05 for crude disease-free survival); the recurrence rate was 16.7 or 24.3% among those consuming > or = 5 cups or < or = 4 cups per day, respectively, in a seven-year follow-up of stage I and II breast cancer, and the relative risk of recurrence was 0.564 (95% confidence interval, 0.350-0.911) after adjustment for other lifestyle factors. However, no improvement in prognosis was observed in stage III breast cancer. Our results indicate that increased consumption of green tea prior to clinical cancer onset is significantly associated with improved prognosis of stage I and II breast cancer, and this association may be related to a modifying effect of green tea on the clinical characteristics of the cancer.


--------------------------------------------------------------------------------

Induction of apoptosis in human stomach cancer cells by green tea catechins.

Oncol Rep, 5(2):527-9 1998 Mar-Apr

The exposure of human stomach cancer KATO III cells to green tea catechin extract and epigallocatechin gallate (EGCG), a main component of the extract led to both growth inhibition and the induction of programmed cell death (apoptosis). Morphological changes showing apoptotic body were observed in the cells treated with green tea catechin extract and EGCG. The fragmentation of DNA to oligonucleosomal-sized fragments, characteristic of apoptosis was determined to be concentration- and time-dependent. These data suggest that drinking of green tea in large amounts is recommended possibly to protect humans from stomach cancer.


--------------------------------------------------------------------------------

Influence of green tea and its three major components upon low-density lipoprotein oxidation.

Exp Toxicol Pathol, 5(2):329-35 1997 Dec

The abilities of green tea extract and its three major components to inhibit lipid peroxidation in low-density lipoprotein (LDL) catalyzed by copper were tested in vitro using malondialdehyde as a parameter of antioxidant activity. The results demonstrated that green tea extract markedly delays peroxidation with a dose-dependent pattern. Of the three components, polyphenols had the strongest action. Similar action was also shown in the theanine-treated group but was weaker than in the former, whereas caffeine had a very limited effect. Based on these data, it is concluded that green tea extract can effectively inhibit peroxidation and that this activity is due largely to the polyphenols it contains. According to the ultraviolet spectra, copper chelation is suggested to be one of the possible mechanisms of LDL antiperoxidation.


--------------------------------------------------------------------------------

Influence of tea catechins on the digestive tract.

J Cell Biochem Suppl, 89(24):52-8 1997

Tea catechins undergo various metabolic changes after they are taken orally, though a large percentage are excreted intact with the feces. Epidemiological studies suggest a protective effect of tea against various human cancers, including colon and rectum. The bactericidal property of tea catechins plays several roles in the digestive tract. In the small intestine, catechins inhibit alpha-amylase activity, and a certain amount is absorbed into the portal vein. Although catechins are bactericidal, they do not affect lactic acid bacteria. Including tea catechins in the diet for several weeks decreases putrefactive products and increases organic acids by lowering pH. These changes were achieved in tube-fed patients by administering 100 mg of tea catechins (equivalent to a cup of green tea) three times daily with meals for 3 weeks. When catechin administration ceased, the effects reversed after 1 week. Catechins should be considered further in colon carcinogenesis studies.


--------------------------------------------------------------------------------

Protective effects of tea polyphenols against oxidative damage to red blood cells.

Biochem Pharmacol, 54(9):973-8 1997 Nov 1

Tea polyphenols (TPP) from black and green teas were evaluated for their antioxidant effects on normal red blood cells (RBC) and beta-thalassemic RBC membranes challenged with exogenous oxidants in vitro. The TPP of both types protected RBC against primaquine-induced lysis; they also protected the whole cells and the membranes against H2O2-induced lipid peroxidation so that about 80% protection was reached at [TPP] = 10 microg/mL. TPP from black tea at the same concentration protected normal RBC from morphological alterations caused by the peroxide treatment. The mechanism of the effects of TPP was investigated using a chemical system generating .OH (iron + ascorbic acid). TPP from both black and green teas inhibited the .OH fluxes in a concentration-dependent manner, indicating the possibility of iron chelation by TPP. Spectrophotometric titration revealed that TPP could stoichiometrically bind ferric iron to form a redox-inactive Fe-TPP complex. Quantitative analysis suggests that one or more major catechins from the TPP preparations are the likely iron-binding compounds accounting for the antioxidant effects of TPP on RBC.


--------------------------------------------------------------------------------

Green tea polyphenols inhibit oxidant-induced DNA strand breakage in cultured lung cells.

Free Radic Biol Med, 310(6981):235-42 1997

The influence of green tea polyphenols (GTP) on the formation of DNA strand breaks (DNA-SB) and lipid peroxidation products (LPP) in cultured human lung cells (A 549) exposed to different oxidants was investigated. Cells were pretreated with GTP for 2 h and then exposed to cigarette smoke solution, H2O2 or FeCl3 for 30 min. After exposure, the cells were analyzed for DNA-SB, LPP, and viability. In addition, the effects of GTP added directly to the incubation mixtures during exposure were examined, using the same end points. It appeared that pretreatment with GTP inhibited both cigarette smoke- and H2O2-induced DNA breakage; i.e., following exposure to cigarette smoke or H2O2, the fraction of DNA passing through a microfilter increased significantly in cells not subjected to GTP, but this effect was prevented or inhibited in GTP-treated cells. Pretreatment with GTP also reduced the overall toxicity of H2O2 as determined by cell growth after exposure. Moreover, addition of GTP during exposure reduced both cigarette smoke- and H2O2-induced DNA breakage as well as formation of LPP after exposure to Fe3+. These results indicate that GTP inhibit the formation of DNA-SB in cells exposed to oxidants. It is possible that this ability to GTP to inhibit DNA-SB formation might contribute to the antitumorogenic properties of green tea.


--------------------------------------------------------------------------------

Effect of tea flavonoid supplementation on the susceptibility of low-density lipoprotein to oxidative modification.

Am J Clin Nutr, 310(6981):261-6 1997 Aug

Dietary flavonoid intake has been reported to be inversely associated with the incidence of coronary artery disease. To clarify the possible role of tea flavonoids in the prevention of atherosclerosis, we investigated the effects of tea flavonoids on the susceptibility of low-density lipoprotein (LDL) to oxidative modification. In an in vitro study, catechins or theaflavins (25-400 mumol/L) were added to plasma and incubated for 3 h at 37 degrees C. Then, the LDL fraction was separated by ultracentrifugation. The oxidizability of LDL was estimated by measuring conjugated diene, thiobarbituric acid-reactive substances (TBARS), and lipid peroxides after cupric sulfate was added. TBARS and lipid peroxides in the supernates were also measured after incubation with macrophages. Catechins significantly (P < 0.01 by ANOVA) and dose-dependently prolonged the lag time before initiation of oxidation. Among the catechins, epigallocatechin gallate exerted the most marked effect, prolonging the oxidation lag time more than vitamin E at the same molar concentration. Theaflavins exerted stronger inhibitory effects than catechins. Macrophage-mediated LDL oxidation was also inhibited by adding these tea flavonoids to the plasma samples. In an in vivo study, 14 healthy volunteers consumed 750 mL black tea/d for 4 wk. After the subjects had consumed tea for 4 wk, the lag time before LDL oxidation was significantly (P < 0.01) prolonged from 54 to 62 min. This minor prolongation occurred despite much lower plasma flavonoids than were used in vitro. No significant change was observed in eight control volunteers. LDL exposed to tea flavonoids in vitro or in vivo reduced oxidizability. We speculate that tea flavonoids may have a role in ameliorating atherosclerosis.


--------------------------------------------------------------------------------

Scavenging effect of extracts of green tea and natural antioxidants on active oxygen radicals.

Cell Biophys, 14(2):175-85 1989 Apr

With the use of the spin trapping methods, the scavenging effects of the extracts of green tea and other natural foods are studied. In stimulated polymorphonuclear leukocytes (PMN) system, water extract fraction 6 (F6) from green tea and green tea polyphenols (GTP) have the strongest scavenging effect on the active oxygen radicals, much stronger than vitamin C (Vc) and vitamin E (VE). Rosemary antioxidants (RA) and Curcumin (Cur) have weaker scavenging effects than Vc, but stronger than VE. In Fenton Reaction, Cur has the strongest scavenging effect (69%) on hydroxyl radicals. In irradiation, riboflavin system F6(74%) and GTP(72%) have very strong scavenging effects that are weaker than Vc, but much stronger than VE (23%). With the use of spin probe oxymetry, the oxygen consumption in respiratory burst of stimulated PMN were measured when the antioxidants existed in these systems. The results demonstrated that these antioxidants did not affect the respiratory burst of human polymorphonuclear leukocytes stimulated with PMA.


--------------------------------------------------------------------------------

Possible contribution of green tea drinking habits to the prevention of stroke.

Tohoku J Exp Med, 157(4):337-43 1989 Apr

Among 5910 nondrinking and nonsmoking women (of greater than or equal to 40 years of age) in a prefectural city of Sendai, and two villages of Taijiri and Wakuya in Miyagi prefecture, Japan, medical history of stroke was less frequently observed among those who took more green tea in daily life. No relation with tea drinking was observed for hypertension history. The uneven distribution of stroke history was detectable even after the effects of age, location of residence, and high salt intake were ruled out. The incidence of stroke and cerebral hemorrhage during a 4-year follow-up of the study population was twice or more times higher in those who took less green tea (less than 5 cups a day) than in those who took more (greater than or equal to 5 cups daily).

[kebaldwin]

could find no evidence to support claims of the beverage's health benefits

In five minutes -- I found all kinds of evidence to support the claims. The FDA is completely and totally irresponsible.

If the FDA had any decency at all ... it would have gone through these studies and found out what made them work and then go through the studies showing no benefit and finding out why they did not work. And report what makes it beneficial and what does not.

[paleowoman]

http://onhealth.webmd.com/script/main/art.asp?articlekey=52395

The link above mentions a tea researcher, 82 year old John Weisberger PHD who has published 500 articles on tea -- he's so convinced of the benefits he drinks 10 cups per day. Says black -- ooolong -- green -- white ALL good -- much of the research was done on green because it was done in countries that drink more green tea than other varieties. New good stuff coming out about oolong (my favorite) with respect to obesity control, eczema, skin aging etc -- do an internet search -- something the FDA is obviously incapable of. Or maybe just too busy approving poisons like statin drugs.

I myself drink 5-10 cups -- it's a joy. Gyokuro, sencha, genmaicha and hojicha for green -- iron goddess and bai hao for oolong.

[Dodger]

In five minutes -- I found all kinds of evidence to support the claims. The FDA is completely and totally irresponsible.

If the FDA had any decency at all ... it would have gone through these studies and found out what made them work and then go through the studies showing no benefit and finding out why they did not work. And report what makes it beneficial and what does not.Almost all those studies were in vitro. What works in a petri dish may not work in a human.

[kebaldwin]

Almost all those studies were in vitro. What works in a petri dish may not work in a human.

In the last group -- I counted 14 studies with 7 involving people and an eighth involving animals.

Again, I don't understand how anyone, medically trained or not,

could find no evidence to support claims of the beverage's health benefits

Suppose every study was in vitro. I don't understand, based on these studies (there are many more), that there is no reason to do further studies on people -- and figure out what makes it work -- and what keeps it from working in other studies.

The bottom line is -- the FDA and their customers will not benefit from further studies so they squashed it.

[Scars]

Thank you for posting the studies kabaldwin - can't imagine why anyone would think that the stuff may be alright for us (rolling eyes)

[lnrpoole]

Inrpool,

Enjoy your BSE-infected beef... oh, and by the way - some may disagree with you on the Hitler thing...

Unlikely, if they have researched the activities of the FDA in the last 30 years. ;)