The antioxidant content of tea could mean that drinking three or more cups a day could reduce the risk of a wide range of health problems, ranging from cancer to heart disease, and may even be healthier than water, says a review from Britain.
"Drinking tea is actually better for you than drinking water. Water is essentially replacing fluid. Tea replaces fluids and contains antioxidants so its got two things going for it," reviewer Dr Carrie Ruxton from Nutrition Communications told the BBC.
Interest in tea have mostly focuses on green tea, with consumption linked to a wide range of health benefits, including lower risk of certain cancers, weight loss, and protection against Alzheimer's.

The health benefits have been linked to the polyphenol content of the tea. Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent.
The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin.
But Dr. Ruxton and her co-authors from King's College London report that black tea also had positive effects on general health.
"We found some research showing that black and green tea contained similar amounts of antioxidants but different types. This can be expected as they come from the same plant but go through different processing," Dr. Ruxton told NutraIngredients.com.
"Antioxidant activity in the blood is similar too so one could assume that both types of tea confer heart health benefits," she said.

The review, sponsored by the Tea Council and published on-line in the European Journal of Clinical Nutrition (doi: 10.1038/sj.ejcn.1602489), searcher databases for relevant epidemiological and clinical studies that were published between 1990 and 2004.
In terms of cardiovascular disease, the reviewers report that "clear evidence was found" to link drinking three of more cups per day could reduce the risk.
Cancer risk did seem to be reduced in experimental (in vitro and animal studies) said the reviewers, but these results were not backed up by epidemiological evidence, they said.
A small note of caution however was noted by the observation that a non-effect or slight increase in risk of colorectal cancer with consumption of black tea.

The researchers also tackled the old wives' tale that drinking tea leads to dehydration, due to the diuretic caffeine content of the beverage. This was not backed up by the science, said the reviewers, with normal levels of hydration maintained when the tea contained less than 250 mg per cup.
"Studies on caffeine have found very high doses dehydrate and everyone assumes that caffeine-containing beverages dehydrate. But even if you had a really, really strong cup of tea or coffee, which is quite hard to make, you would still have a net gain of fluid," Dr. Ruxton told the BBC.

The reasons for these benefits was proposed to be related to the antioxidant action of tea polyphenols, wrote the reviewers.
"There was sufficient evidence to show risk reduction for CHD at intakes of more than three cups per day and for improved antioxidant status at intakes of one to six cups per day," concluded the reviewers.
"A maximum intake of eight cups per day would minimize any risk relating to excess caffeine consumption. Black tea generally had a positive effect on health."
(Source : http://www.nutraingredients.com)

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For many consumers, antioxidant doesn’t go beyond vitamins C and E, and beta-carotene, but as understanding of the antioxidant compounds in fruit and vegetables increases, more research is pointing towards the potential of polyphenols.
In the final part of its series on antioxidants, NutraIngredients looks at the rise of polyphenols and flavonoids, and what still needs to be done.
Data from Leatherhead Food International (LFI) shows that the world functionalantioxidants market is increasing year on year by around 3 per cent, and was valued at US$ 400 million in 2004, and US$ 438 million in 2007. Europe, the US, and Japan account for 90 per cent of this market.

With flavonoids and polyphenols reported to be 45 per cent of this functional antioxidant market, equivalent to almost US$ 200 million, it is no wonder that many companies are already offering such ingredients, including Naturex, Burgundy, Chr. Hansen, DSM, Futureceuticals, Danisco, Indena, Frutarom, Genosa, Natraceutical, Cognis, and ADM.
However, while the science is beginning to point to the significant potential and benefits of polyphenols, Ming Hu from the University of Houston recently issued "a call to arms" for more relevant research into the bioavailability and utilisation of the antioxidants, particularly polyphenols, in order to help "the successful development of polyphenols as chemopreventive agents in the future".

Definitions:
Polyphenols are receiving extensive research due to their potent antioxidant activity, their ability to mop-up harmful free radicals, and the associated health benefits. Many have also been implicated in possible protection against diseases such as cancer and cardiovascular disease, while some have been reported to potentially offer protection from Alzheimer's.
A recent study by French researchers using a series of antioxidant assays, including DPPH, ABTS, ORAC, SOD, FRAP of extracts from 30 plants found a“significant relationship between antioxidant capacity and total phenolic content […], indicating that phenolic compounds are the major contributors to the antioxidant properties of these plants” (J. Agric. Food Chem., 2009, Vol. 57, pp. 1768-1774).

Furthermore, according to an editorial in the American Journal of Clinical Nutrition (July 2008, Vol. 88, pp. 12-13), Johanna Geleijnse and Peter Hollman from Wageningen University in the Netherlands stated that the contribution of flavonones to a person's antioxidant capacity was significant.
"More than 6000 different flavonoids in plants have been described, and their total intake could amount to 1 g/d, whereas combined intakes of beta-carotene, vitamin C, and vitamin E from food most often are less than 100 mg/d," they said.

The chemical class refers to compounds called phenylpropanoids, which includes flavonoids, and hydrolyzable tannins such as the gallic acid esters of glucose,
Flavonoids can be split into a number of sub-classes, including anthocyanins found in berries, flavonols from a variety of fruit and vegetables, flavones from parsley and thyme, for example, flavanones from citrus, isoflavones from soy, mono- and poly-meric flavonols like the catechins in tea, and proanthocyanidins from berries, wine and chocolate. The non-flavonoids include phenolic acids, lignans, and stilbenes such as resveratrol.

Structure is key
Polyphenols, and flavonoids in particular, are not all created equal. For example, scientists from The Ohio State University reported that the structure of anthocyanins, the antioxidant pigments from a range of fruit and vegetables, is key to the cancer fighting abilities.
According to findings published in the Journal of Agricultural and Food Chemistry(doi: 10.1021/jf8005917), certain types of anthocyanins have greater activity against colon cancer than others.
“The chemical structures of anthocyanins do have a significant impact on their biological activity, and data suggest that non-acylated monoglycosylated anthocyanins are more potent inhibitors of colon cancer cell growth proliferation,” wrote lead author Pu Jing.
The researchers cautioned that more research is necessary to explore the role of anthocyanin structure and the chemo-protective effects.
Much work left to do…

In addition to the potential benefits for reducing the risk of cancer, the most science has pointed towards a protective role in cardiovascular health. Geleijnse and Geleijnse added, however, that significant study was still needed in this area.
"Substantial evidence for a vasoprotective effect of specific flavonoids is, however, still lacking. Optimal doses of specific flavonoids for cardiovascular protection […] are still beyond the horizon,” they wrote in the American Journal of Clinical Nutrition.
“Flavonoid research has made large progress since the [early days], but, to really advance the field, the step to individual flavonoids must be made now."
(Source : http://www.nutraingredients.com)

Drinking a cup of polyphenol-enriched oolong tea with a high fat meal may increase the amount of cholesterol excreted by the body by half, says a small study from Japan and Taiwan.
The results, which suggest a heart-healthy benefit for the tea, add to an ever-growing body of science linking consumption to a wide range of health benefits, including lower risk of certain cancers, weight loss, and protection against Alzheimer's.

The health benefits, which have mainly focused on green tea, have been linked to the polyphenol content of the tea. Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent. Oolong tea is semi-fermented tea and is somewhere between green and black tea.
The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin.

The new research, published in the current issue of the European Journal of Clinical Nutrition (Vol. 60, pp. 1330-1336), was led by Keiichi Abe from Institute for Health Care Science, Suntory Ltd, and included researchers from the University of Tokushima and Providence University, Taiwan.
The scientists recruited twelve healthy aduls (nine women, averag age 22) and randomly divided them into two groups, one to receive 38 g of fat from potato chips (19 g within 30 minutes of eating lunch and dinner) and 750 ml of a placebo- or polyphenol-enriched oolong tea at three meals in a double-blind placebo-controlled crossover design.
A seven-day washout period separated the ten-day intervention periods, and blood samples were collected after days 8, 18, 25 and 35. Three faecal samples were also collected in order to measure lipid excretion levels.
The Japanese-Taiwanese researchers report that faecal lipid excretion was significantly increased during the polyphenol-enriched oolong tea period, compared to placebo (19.3 versue 9.34 g/3day, respectively).

The polyphenol-enriched oolong tea period was also associated with a 50 per cent increase in cholesterol excretion, compared to the placebo-teat group (10.8 versus 1.2 g/3day, respectively).
High cholesterol levels, hypercholesterolaemia, have a long association with many diseases, particularly cardiovascular disease (CVD), the cause of almost 50 per cent of deaths in Europe, and reported to cost the EU economy an estimated €169bn ($202bn) per year.
"The results of this study indicated that polyphenol-enriched oolong tea could increase lipid excretion into feces when subjects took high-lipid diet," concluded the researchers.

More research with a larger study population is needed, in addition to mechanistic studies to elucidate the underlying mechanism by which the polyphenols appear to reduce fat absorption. But the results are in agreement with other studies that have linked red wine consumption, polyphenol-rich green tea or pine bark extracts to improved cardiovascular risk factors.
This study is good news for both the tea market and the tea extract market. European demand for tea extracts is currently surging, having reached 500 metric tonnes by 2003.

This has seen companies such as DSM, with its Teavigo boasting 95 per cent purity of EGCG, and Taiyo International, with its Sunphenon claiming more than 90 per cent purity, position themselves firmly in specific catechin markets.
(Source : http://www.nutraingredients.com)

Polyphenols in tea may preferentially suppress the growth of pathogenic bacteria in the gut, but not the growth of 'friendly' bacteria, says a new study from Singapore.
"It is generally believed that possible beneficial health effects of tea polyphenols are due to their anti-oxidant activity," wrote lead author Hui Cheng Lee from the National University of Singapore.
"Evidence from our study indicates that phenolics are likely to benefit the host by inhibiting pathogen growth and regulating commensal bacteria, including probiotics, and could therefore be considers as prebiotics."

The health benefits of tea ranging from a lower risk of certain cancers to weight loss, and protection against Alzheimer's, have been linked to the polyphenol content of the tea. Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent. Oolong tea is semi-fermented tea and is somewhere between green and black tea.
The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin.
The new study, published in the Elsevier journal Research in Microbiology, looked at the effects of 31 different phenolics extracted from Yunnan Chinese tea on the growth of 28 different bacteria, including pathogenic, commensal (normal), and probiotics found in the intestine. These included strains of the aerobic pathogens E. coli, Salmonella, and Listeria, and probiotic Lactobacillusstrains, and strains of the anaerobic pathogens Bacteroides and Clostridium,and probiotic Bifidobacterium strains.

Cells were cultured in the presence of 0.1 per cent polyphenols at 37 degrees Celsius for 24 hours.
"Our data demonstrate that phenolic compounds have general inhibitory effects on intestinal bacteria. The level of inhibition varies depending on the bacterial species and chemical structure of the compound," wrote Lee. Indeed, growth of the pathogenic E. coli and Salmonella typhimurium were most strongly inhibited by the tea polyphenols and their metabolites,as were strains belonging to the Bacteroides and Clostridium genera.

However, the researchers report that the growth of the probiotic Bifidobacteriumand Lactobacillus strains were less affected by the tea compounds.
"Since probiotic growth was relatively unaffected by most of the aromatic compounds tested, probiotic colonization in the intestine should continue in the presence of phenolics so as to improve the intestinal microbial balance and inhibit pathogen growth," said the researchers.
"Although not fully comprehensive, this in vitro study indicates a substantial number of complex interactions between intestinal bacteria, phenolics and their metabolism," they said.
They called for more research to further investigate the influence of the tea polyphenols on gut microflora, and the overall maintenance of human health and disease prevention, and said that the research suggests that the antioxidants may also be prebiotic.

Prebiotic ingredients, or those that boost the growth of beneficial probiotic bacteria in the gut, are worth about €90 million in the European marketplace but are forecast to reach €179.7 million by 2010, according to Frost & Sullivan.
The market has been largely created by three inulin producers, all based in Europe, but other ingredient manufacturers are increasingly looking to promote the prebiotic effect of their products as evidence suggests that prebiotics could be even more useful than the probiotic bacteria that they feed.

Source: Research in Microbiology
2006, Volume 157, Pages 876-884
"Effect of tea phenolics and their aromatic fecal bacterial metabolites on intestinal microbiota"
Authors: H.C. Lee, A.M. Jenner, C.S. Low, Y. K. Lee

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Regular consumption of green tea may reduce a woman’s risk of breast cancer by about 12 per cent, according to a new study from the US and China.
Writing in the Journal of Nutrition, scientists report that the “modest” reduction was observed for regular tea drinkers, compared to non-drinkers, after evaluating the diet of 3454 women with breast cancer and 3474 healthy controls aged between 20 and 74.
The study, led by Martha Shrubsole from Vanderbilt School of Medicine in Nashville, adds to the ever-growing body of science supporting the anti-cancer benefits of green tea and its polyphenols.

Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent. Oolong tea is semi-fermented tea and is somewhere between green and black tea.
The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC).

Study details
Shrubsole and her collaborators from the Shanghai Cancer Institute and the Shanghai Center for Disease Prevention and Control performed the study in Shanghai. All of the women were individually interviewed and their green tea drinking habits, including regularity, tea strength, and quantities consumed, were assessed.
Regular consumption of the beverage was associated with a “slightly decreased risk for breast cancer” of 12 per cent, said the researchers, compared to non-drinkers.
Furthermore, benefits for pre-menopausal women were related to the number of years they had been regular drinkers, and a dose-response was also observed

On the other hand, the researchers found no relationship between a specific genotype called COMT rs4680 AA and breast cancer risk. The enzyme catechol-O-methyltransferase (COMT) is known to catalyse tea polyphenols, and the lower activity associated with COMT rs4680 AA was hypothesised to affect the relationship between green tea and breast cancer risk.
“Drinking green tea may be weakly associated with a decreased risk of breast cancer,” concluded the researchers
Beyond cancer
In addition to the potential anti-cancer benefits, previous studies have reported a range of health benefits for green tea and its extracts, including the potential to promote weight loss, and protection against Alzheimer's.
European demand for tea extracts is currently surging, having reached 500 metric tonnes by 2003.
This has seen companies such as DSM, with its Teavigo boasting 95 per cent purity of EGCG, and Taiyo International, with its Sunphenon claiming more than 90 per cent purity, position themselves firmly in specific catechin markets.

Source: Journal of Nutrition
February 2009, Volume 139, Number 2, Pages 310-316
“Drinking Green Tea Modestly Reduces Breast Cancer Risk”
Authors: M.J. Shrubsole, W. Lu, Z. Chen, X.O. Shu, Y. Zheng, Q. Dai, Q. Cai, K. Gu, Z.X. Ruan, Y.-T. Gao, W. Zheng

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Antioxidant compounds in green tea could help promote exercise-induced abdominal fat loss, according to a new study from the American Society of Nutrition.
Cetechins are a sub-class of flavonoids, or antioxidant compounds. Green tea is a rich source of catechins, which are thought to play a beneficial role in reducing the risk of various diseases, including Alzheimer's, certain cancers, cardiovascular and oral health.
Precious studies have also suggested that tea catechins may help promote weight loss. The current study, published in The Journal of Nutrition, found that consuming a beverage containing green tea catechins (625mg/d) may enhance exercise-induced loss of abdominal fat and improve triglyceride levels.

Double-blind
Researchers recruited just over 100 adults between the ages of 21 and 65. The participants were all healthy and “normally sedentary”, with a mean BMI of 32kg/m². Most subjects were of non-Hispanic white ethnicity.
Male participants, who made up about half of the total study group, had a waist circumference of over 90cm, while women had a waist circumference of over 87cm. Cholesterol levels were over 5.2mmol/L.
The subjects were randomly assigned to receive either 500ml per day of a beverage providing 625mg catechins, or a control beverage containing added caffeine to match the caffeine content of the catechin beverage.

Both the active and the control beverage contained water, sodium chloride, artificial citrus flavouring, glucose, erythritol, and sucralose. Each 500ml serving provided 63kj (15 Kcal) of energy. Participants agreed not to consume more than two caffeinated beverages per day, including the study product, during the 12-week study period.
Participants consumed one serving of their assigned beverage per day, at any time of the day, and with or without food. They continued their usual energy intake, and three-day diet records were taken at baseline, six and 12 weeks.
During the study period, the subjects committed to 180 minutes of “moderate-intensity” physical activity per week, and to attend at lease three supervised exercise sessions per week.

Body weight loss
At the end of the study period, people in the catechin group were found to have lost more body weight compared to the control group (P = 0.079).
There were no significant differences between the two groups in changes in waist circumference or fat mass. However, both total abdominal fat area (P = 0.013)and abdominal subcutaneous fat area (P = 0.019) had decreased more in the catechin group.
The researchers concluded: “The findings of this study suggest that consumption of a beverage containing green tea catechins (625mg/d) may enhance exercise-induced loss of abdominal fat and improve circulating FFA and TG levels. Additional research is warranted to further clarify the mechanisms responsible for these effects.”
Source:
Tea catechins and exercise-induced weight loss
The Journal of Nutrition
doi: 10.3945/jn. 108098293
Authors: Kevin C. Maki, Matthew S. Reeves, Mildred Farmer, Koichi Yasunaga, Noboru Matsuo, Yoshihisa Katsuragi, Masanori Komikado, Ichiro Tokimitsu, Donna Wilder, Franz Jones, Jeffrey B. Blumberg and Yolanda Cartwright

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Extracts from black tea may reduce total cholesterol levels by nine per cent and LDL cholesterol levels by 12 per cent, according to a new study from Japan.

Consumption of the black tea extract (BTE) was also associated with beneficial changes in blood levels of triglycerides and body weight, according to results published in the journal Nutrition Reviews.
High cholesterol levels, hypercholesterolaemia, have a long association with many diseases, particularly cardiovascular disease (CVD), which is the number one killer on both sides of the Atlantic.
"The present study is the first to report that BTE (one gram per day) significantly lowered total cholesterol and LDL cholesterol levels in human subjects with borderline hypercholesterolemia in a randomised double-blind placebo-controlled study," wrote authors Hiroyuki Fujita and Tomohide Yamagami from the R&D Department of Nippon Supplement in Osaka.
The study involved 47 people with borderline hypercholesterolaemia assigned to receive the BTE or placebo for three months.

The health benefits of tea have been linked to the polyphenol content of the tea. Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidised by fermentation) contains between 3 and 10 per cent.
The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin.

Study details
The subjects, aged from 40 to 70 years, were randomly assigned to receive the black tea extract (one gram per day) or placebo for three months. The subjects consumed the pills before a meal.
After three months, a 9 per cent reduction in total cholesterol was observed in the tea extract group, from 6.14 to 5.62 moles per litre at the start and end of the study, respectively. Furthermore, LDL cholesterol levels fell by 12 per cent, from 4.32 to 3.81 moles per litre.
Similar reductions in triglyceride levels were observed, but no significant changes in any blood lipid levels were recorded in the placebo group.

"Interestingly, the reduced levels of total cholesterol, LDL cholesterol, and TG levels remained significant even one month after termination of black tea extract intake," wrote Fujita and Yamagami.
The authors also note no "undesirable changes in other biochemical parameters", such as fat-soluble vitamins. Moreover, none of the subjects reported any adverse effects from consumption of the black tea extracts.

Mechanism
Fujita and Yamagami postulated that the tea extract may function by inhibiting the reabsorption of bile acids. By binding to the bile acids the extracts increase the excretion of cholesterol - the liver compensates by producing more bile from cholesterol, thereby promoting cholesterol lowering.
"Because the black tea extract induces the precipitation of mixed bile salt micelles and lowers blood cholesterol levels, it might have contributed to body weight loss in this study," they wrote.
"In this regard, further investigation of black tea extract effects on body weight loss is warranted," they concluded.
They also stated that future studies should investigate if the extract can play a role in reducing arteriosclerosis related to the metabolic syndrome and obesity in humans.
Source: Nutrition Research (Elsevier)
July 2008, Volume 28, Issue 7, Pages 450-456
"Antihypercholesterolemic effect of Chinese black tea extract in human subjects with borderline hypercholesterolemia"
Authors: H. Fujita, T. Yamagami

Drinking at least 23 cups of black tea a month, or about three-quarters of a cup a day, may slash the risk of developing Parkinson's disease by a whopping 71 per cent, suggests new research from Singapore.
The benefits of the beverage were not linked to the caffeine content, suggest the results of the study of 63,257 Chinese men and women published in theAmerican Journal of Epidemiology.

Parkinson's disease is a degenerative condition affecting movement and balance in more than one million Americans each year, a figure expected to rise due to ageing populations.
Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent. Oolong tea is semi-fermented tea and is somewhere between green and black tea.

The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC).
Despite results from previous studies reporting that green tea may reduce the risk of Parkinson's, the new study, reported no benefits among participants of the Singapore Chinese Health Study.
Lead author Louis Tan from Singapore's National Neuroscience Institute states that data was collected through in-person interviews using structured questionnaires.

Over the course of the study, 57 incident cases of Parkinson's disease were documented, and while caffeine was associated with a protective effect, reducing disease risk by 45 per cent, the benefits of black tea were not affected by caffeine content, wrote Tan and co-authors.
"Black tea, a caffeine-containing beverage, showed an inverse association with Parkinson's disease risk that was not confounded by total caffeine intake or tobacco smoking," wrote the authors.
"Ingredients of black tea other than caffeine appear to be responsible for the beverage's inverse association with Parkinson's disease," they concluded.

Tea Advisory Panel welcomes the results
Commenting on the study, Dr Ann Walker, a member of The Tea Advisory Panel (TAP) said that the latest research study was great news for all UK 'black tea' drinkers.
"In the past there seems to have been more of a focus by scientists reviewing the health benefits of green tea," she said.
She added that previous studies looking at tea drinking and Parkinson's disease risk did not differentiate between black tea and green tea, while the protective effect of tea were attributed to the caffeine content.

"In the current study, however, the beneficial effect of black tea did not appear to be influenced by caffeine intake, indicating that ingredients other than caffeine are responsible for black tea's protective effects," said Dr. Walker.
"A key difference between black tea and green tea lies in the types and amounts of flavonoids. Green teas contain more of the simple flavonoids called catechins. But when black tea is made, the catechins undergo oxidation resulting in the generation of more complex varieties, called thearubigins and theaflavins."
"The underlying mechanisms for this protective effect of black tea on Parkinson's disease remains unclear until further research is done. But drinking even one cup of black tea per day could help to reduce the risk of Parkinson's disease,"she concluded.

Source: American Journal of Epidemiology
Published online ahead of print 20 December 2007, doi: doi:10.1093/aje/kwm338
"Differential Effects of Black versus Green Tea on Risk of Parkinson's Disease in the Singapore Chinese Health Study"
Authors: Louis C. Tan, W.-P. Koh, J.-M. Yuan, R. Wang, W.-L. Au, J.H. Tan, E.-K. Tan, M.C. Yu

Drinking tea regularly may lead to improvements in bone health similar to that observed with calcium or physical exercise, suggests new research from Australia.
Writing in the October issue of the American Journal of Clinical Nutrition, Amanda Devine and co-workers from the University of Western Australia report that bone mineral density levels were 2.8 per cent greater in tea drinkers than non-tea drinkers, suggesting the beverage has the potential to aid in the prevention of osteoporosis.
The condition is currently second only to cardiovascular disease in terms of global healthcare burden, according to the World Health Organisation, affecting some 200 million people today but the number of sufferers is set to increase steadily with growing numbers of elderly living longer, and obesity adding extra strain on bones.

The new study involved 1500 elderly women (age range 70 to 85) taking part in a five year prospective trial looking at the effects of oral calcium supplements on osteoporotic fractures. Tea consumption data were collected using 24 hour dietary recall in a subset of 275 subjects, while all the subjects completed a self-administered food frequency questionnaire on beverage consumption at the end of the trial.
Devine and co-workers report that total bone mineral density (BMD) was 2.8 per cent higher in tea drinkers, compared to non-tea drinkers. Over the course of four years, the researchers add that tea drinkers lost an average of 1.6 per cent of their total hip BMD, while non-tea drinkers lost significantly more (4.0 per cent).
"Tea drinking is associated with preservation of hip structure in elderly women. This finding provides further evidence of the beneficial effects of tea consumption on the skeleton," they concluded.

The results add to an ever-growing body of science linking consumption to a wide range of health benefits, including lower risk of certain cancers, weight loss, heart health, and protection against Alzheimer's.
Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent.
The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin.

Indeed, it is these polyphenols that were identified by Devine and co-workers as the potential bioactives in the beverage.
"Tea-derived flavonoids and lignans may be important in maintaining BMD, particularly in older women, who have low concentrations of endogenous oestrogen," wrote Devine. "A recent review suggests that flavonoids from green tea may be associated with increases in BMD via a potent stimulatory effect on osteoblast function."
"A major tea flavonoid, (-)-epigallocatechin-3-gallate, has been shown to increase the expressions of osteogenic genes, elevate bone marker activity, and augment mineralization in a murine bone marrow mesenchymal stem cell line.

"These findings suggest a stimulatory effect of the compound as a possible mechanism for the associated higher BMD seen in tea drinkers," she said.

Source: American Journal of Clinical Nutrition
October 2007, Volume 86, Pages 1243-1247.
"Tea drinking is associated with benefits on bone density in older women"
Authors: Amanda Devine, J.M. Hodgson, I.M. Dick, and R.L. Prince

Drinking black tea could reduce stress hormone levels and help ease the burden of heart disease, says the first randomized clinical trial into the effects of the beverage on stress.
"This has important health implications, because slow recovery following acute stress has been associated with a greater risk of chronic illnesses such as coronary heart disease," said lead researcher Professor Andrew Steptoe from University College London.

The researchers, from UCL and Unilever Research Colworth, found that drinking four cups of black tea every day for six weeks reduced blood levels of the stress hormone cortisol by 20 per cent more than the placebo group, backing up the 'old wives tale' that tea helps people relax.
"Drinking tea has traditionally been associated with stress relief, and many people believe that drinking tea helps them relax after facing the stresses of everyday life," said Steptoe. "However, scientific evidence for the relaxing properties of tea is quite limited. This is one of the first studies to assess tea in a double-blind placebo controlled design."

The study, published on-line ahead of print in the journal Psychopharmacology(doi 10.1007/s00213-006-0573-2), recruited 75 healthy young male volunteers (average age 33). The men were put through a four-week wash-out period before the study, withdrawing consumption of tea, coffee, other caffeinated drinks, aspirin, ibuprofen, dietary supplements, and various fruit and vegetables rich in flavonoids.
They were then randomly assigned to the black tea group (37 men, four cups of black tea per day) or the placebo group (38 men, a caffeinated drink identical in taste, but devoid of the active tea ingredients) for six weeks.

Both groups were subjected to challenging tasks, while their cortisol, blood pressure, blood platelet and self-rated levels of stress were measured. In one task, for example, the subjects were asked to verbally respond in front of camera and argue their case after being exposed to one of three stressful situations (threat of unemployment, a shop lifting accusation or an incident in a nursing home).

The tasks triggered significant increases in blood pressure, heart rate and subjective stress ratings in both of the groups, and no difference was observed between the groups concerning blood pressure or heart rate. However, 50 minutes after the task, cortisol levels had dropped by an average of 47 per cent in the tea drinking group compared with 27 per cent in the fake tea group.
The researchers also found that blood platelet activation - linked to blood clotting and the risk of heart attacks - was lower in the tea drinkers, and that this group reported a greater degree of relaxation in the recovery period after the task.

"Tea, therefore, appears to influence the effectiveness of post-stress recovery, rather than the magnitude of stress responses themselves," wrote the reviewers.
The news adds to a growing list of benefits that has linked tea and tea extracts, particularly the catechin, epigallocatechin gallate (EGCG) to reducing the risk of Alzheimer's, certain cancers, as well as having a role in weight loss.
Indeed, European demand for tea extracts is currently surging, having reached 500 metric tonnes by 2003.
Steptoe and his fellow researchers however could not identify which of the compounds in tea, either independently or synergistically, were behind the benefits observed in this clinical trial.

"Tea is chemically very complex, with many different ingredients," he said."Ingredients such as catechins, polyphenols, flavonoids and amino acids have been found to have effects on neurotransmitters in the brain, but we cannot tell from this research which ones produced the differences."
The researchers do reference previous results from both animal and human studies that report that tea flavonoids have an effect on the sympathetic nervous system of rats, the amino acid theanine found in tea increased brain wave activity in specific areas of the human brain, and EGCG has been reported to have a sedative effect and reduce responses to separation stress.

"Nevertheless, our study suggests that drinking black tea may speed up our recovery from the daily stresses in life. Although it does not appear to reduce the actual levels of stress we experience, tea does seem to have a greater effect in bringing stress hormone levels back to normal."
The research was funded by UK's BBSRC, Unilever Research and the British Heart Foundation.

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Drinking at least one cup of tea a day could cut the risk of cancer in the gallbladder and bile ducts by about 40 per cent, suggests a population-based study from China.
The news adds to a growing list of benefits that has linked tea and tea extracts, particularly the catechin, epigallocatechin gallate (EGCG) to reducing the risk of Alzheimer's, certain cancers, as well as having a role in weight loss.
Indeed, European demand for tea extracts is currently surging, having reached 500 metric tonnes by 2003.
This has seen companies such as DSM, with its Teavigo boasting 95 per cent purity of EGCG, and Taiyo International, with its Sunphenon claiming more than 90 per cent purity, position themselves firmly in specific catechin markets.
The new study, published in the June issue of the International Journal of Cancer(Vol. 118, pp. 3089-3094), adds to the body of science by considering the effects of tea drinking on cancer in the gallbladder and bile ducts, cancers that are described as "rare but highly fatal malignancies."
The researchers, led by Ann Hsing from the US National Cancer Institute, assessed the demographic, medical and dietary histories of 627 people with bile tract cancers (cases), 1037 people with bile stones, and 959 randomly selected healthy controls.

The sample population was based in Shanghai, China, where the incidence of these types of cancers is reported to have increased in recent years.
Tea drinkers were defined as anyone who drank at least one cup of tea per day for at least half a year.
"Among women, tea drinking was associated with lower risks of gallbladder and bile duct cancers and of biliary stones," reported the researchers.
Specifically, women tea drinkers had associated reduced risks of gallbladder cancer, bile duct cancer, and bile stones of 44, 35, and 27 per cent, respectively.
For men, no significant association was observed for tea drinkers and the relative risk of these conditions.

These results may have been affected, wrote Hsing and her colleagues, by the high number of smokers amongst the men, which may affect the incidence of these types of cancers.
"These findings add to the accumulating epidemiological evidence linking tea consumption with a lower risk of various cancers, particularly of the digestive tract," said the researchers.

The mechanism by which tea exerts a benefit is not clear, said the scientists, but"may involve anti-proliferative and anti-inflammatory properties of tea polyphenols, in particular EGCG."The researchers also mention that a plausible explanation may be due to effects of EGCG on oestrogen biosynthesis and other hormonal processes, which may help explain the benefits observed in women and not men.
The researchers called for future studies to replicate these results in other populations, as well as focussing study on elucidating the hormonal or other mechanism involved.

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Both green and black tea could protect against age-related diseases like Alzheimer's, says a new study, adding yet more support to the benefits of tea extract on brain health.
"We looked at the protective effects of two tea extracts and their main constituents, called catechins, on dying nerve cells," explained senior author Rémi Quirion from Douglas Hospital Research Centre, Quebec.

The research, published in the European Journal of Neuroscience (Vol. 23, pp. 55-64), claims to be the first to show beneficial effects of both green and black tea on cell cultures treated with amyloid proteins. Amyloid proteins are associated with the onset of Alzheimer's disease, the most common form of dementia and currently affects over 13 million people worldwide.
The direct and indirect cost of Alzheimer care is over $100 billion (€81 billion) in the US alone. The direct cost of Alzheimer care in the UK was estimated at £15 billion (€22 billion).

Although the mechanism of Alzheimer's is not clear, more support is gathering for the build-up of plaque from amyloid deposits. The deposits are associated with an increase in brain cell damage and death from oxidative stress.
The researchers used rat hippocampal cells as models for human cells, and found that addition of the beta-amyloid protein was toxic and killed the cells.

However, both green and black tea extracts, with concentration levels between five and 25 micrograms per millilitre, were found protective activity against the effects of the amyloid protein.
"These effects were shared by [tea extracts] gallic acid, epicatechin gallate (ECG), and epigallocatechin gallate (EGCG), the former being the most potent flavon-3-ol. In contrast, epicatechin and epigallocatechin (ECG) were ineffective in the same range of concentrations," reported lead author Stéphanie Bastianetto.

Both EGCG and gallic acid were found to stop the amyloid aggregation, which could result in plaque formation, and also stopped potentially poisonous amyloid derivatives that would be diffusible across cell membranes.
"These data support the hypothesis that not only green but also black teas may reduce age-related neurodegenerative diseases, such as Alzheimer's disease,"concluded Bastianetto.

It is known that the catechins can be extracted from both green and black teas, but the yield from the unfermented green tea leaf is significantly higher. Green tea is said to contains about 70 mg catechins per 100 mL, whereas black tea contains only about 15 mg per 100 mL.

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Compounds found in tea can stop the growth of bacteria that cause bad breath, according to researchers at the University of Illinois at Chicago.
Polyphenols, chemical components of tea, prevent both the growth of bacteria responsible for bad breath and the bacteria's production of malodorous compounds, the UIC researchers found.

The findings were presented this week at the annual meeting of the American Society for Microbiology in Washington, D.C. by Christine Wu, professor of periodontics and associate dean for research at the UIC College of Dentistry, and research associate Min Zhu.
Bad breath - or halitosis - afflicts a large portion of the population. It is caused by foul-smelling volatile sulphur compounds, like hydrogen sulphide, produced by anaerobic bacteria that thrive in environments lacking oxygen, such as the back of the tongue and deep gum pockets.

In the laboratory study, Wu and Zhu incubated tea polyphenols with three species of bacteria associated with bad breath for 48 hours. At concentrations ranging from 16 to 250 micrograms per millilitre, the polyphenols inhibited growth of the oral bacteria. At even lower concentrations - from 2.5 to 25 micrograms per millilitre - the polyphenols hindered the enzyme that catalyses the formation of hydrogen sulphide, cutting its production by 30 per cent, they reported.
Wu said the present study complements earlier research in her laboratory showing that black tea suppresses the growth of bacteria in dental plaque and that rinsing with black tea reduces plaque formation and the production of acids that cause tooth decay.

"Besides inhibiting the growth of pathogens in the mouth, black tea and its polyphenols may benefit human oral health by suppressing the bad-smelling compounds that these pathogens produce," Wu said.
The polyphenols found in tea include chemicals called catechins and theaflavins. Catechins are found in both green and black teas, while theaflavins are found predominantly in black tea.
Black tea, an aqueous infusion of dried leaves of the Camellia sinensis plant, is the most popular beverage worldwide, second only to water.

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Drinking tea appears to prime the immune system to fight infection and chronic disease, according to US researchers.
There is already a significant body of evidence backing tea's health benefits which focuses mainly on its antioxidant activities. The new research suggests that there may be a further action on health.

In an experiment, people who drank five to six small cups of black tea daily for two weeks were better able to fight off bacterial infections, report the researchers in the early online edition of the Proceedings of the National Academy of Science.
In the study, researchers from Brigham and Women's Hospital and Harvard Medical School in Boston, Massachusetts measured the activity of gamma delta T cells in people who were not regular tea-drinkers.

Gamma delta T cells act to prevent and reduce the effects of disease. Previous experiments have shown that exposing these cells to ethylamine, produced when the tea ingredient L-theanine is broken down in the liver, boosted the abilities of the cells to fight infections.
Ethylamine is also found in other plant products such as mushrooms, apples, and wine, and has even been shown to attack cancer tumours.

In the lab, the scientists extracted exposed gamma delta T cells from people to ethylamine or to placebo and then mixed both sets with bacteria. Those that had not been exposed to ethylamine showed no signs of fighting the bacteria. However, cells that had been previously exposed to the tea component multiplied ten times, and produced significant disease-fighting chemicals.

The researchers also carried out in vivo studies on people who either drank about 20 ounces of tea a day for two weeks, or consumed coffee instead. The tea drinkers' gamma delta T cells produced a wealth of anti-bacterial chemicals when exposed to bacteria. In contrast, people who drank coffee during the study produced no disease-fighting proteins in response to bacteria.
It is thought that while tea drinkers will still get sick, they may have milder symptoms.

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25 Benefits of Green Tea

Green tea prevents obesity by stopping the movement of glucose in fat cells. If you are on a healthy diet, exercise regularly and drink green tea, it is unlikely you'll be obese.

Green tea improves lipid and glucose metabolisms, prevents sharp increases in blood sugar level, and balances your metabolism rate.

Catechin found in green tea can kill bacteria which causes food poisoning and kills the toxins produced by those bacteria.

Blood sugar tends to increase with age, but polyphenols and polysaccharides in green tea help lower your blood sugar level.

Polyphenols and flavenoids found in green tea help boost your immune system, making your health stronger in fighting against infections.

Green tea prevents you from getting a cold or flu. Vitamin C in green tea helps you treat the flu and the common cold.

Theophylline in green tea relaxes the muscles which support the bronchial tubes, reducing the severity of asthma

Green tea helps with ear infection problem. For natural ear cleaning, soak a cotton ball in green tea and clean the infected ear.

Green tea increases the effectiveness of topical interferon treatment of herpes. First green tea compress is applied, and then let the skin dry before the interferon treatment.

Green tea destroys bacteria and viruses that cause many dental diseases. It also slows the growth of bacteria which leads to bad breath.

L-theanine, which is a kind of amino acids in green tea, can help relieve stress and anxiety.

EGCG found in green tea relieves allergies. So, if you have allergies, you should really consider drinking green tea.

Scientists in Japan have found that EGCG (Epigallocatechin Gallate) in green tea can stop HIV from binding to healthy immune cells. What this means is that green tea can help stop the HIV virus from spreading.