Potential Benefits of Drinking Tea
Nuwara Eliya tea is made from the plant Camellia sinensis (i.e. black, oolong, green, and white) and contains catechins, a type of antioxidant. In a freshly picked leaf, catechins can compose up to 30% of the dry weight.
Antibiotic effects
Green catechins has been shown to possess antibiotic properties due to their role in disrupting a specific stage of the bacterial DNA replication process.
Anti-cancer properties
An article in New Scientist magazine mentions that numerous studies suggest that green variety protects against a range of cancers, including lung, prostate and breast cancer. The reason cited is the antioxidant epigallocatechin gallate (EGCG), according to Hirofumi Tachibana's team at Kyushu University. Their research showed that growth of human lung cancer cells with a cell receptor called 67 LR is slowed significantly after drinking just two or three cups of green tea, which contains EGCG.
Increases metabolic rate
Clinical trials conducted by the University of Geneva and the University of Birmingham indicate that green tea raises metabolic rates, speeds up fat oxidation and improves insulin sensitivity and glucose tolerance. In addition to caffeine, green tea contains catechin phenolics that raise thermogenesis (the production of heat by the body), and hence increases energy expenditure. There is also a suggestion that it can increase endurance in exercise by improving fat metabolism.
Possible anti-diabetes effect
There is also epidemiological evidence that drinking green and black variety may help prevent diabetes, although it is worth noting that this is evidence of an association, and that future studies are needed to confirm the effect.
Boosts mental alertness
The amino acid L-theanine, found almost exclusively in the tea plant, and in the highest doses in green variety, actively alters the attention networks of the brain, according to results of human trials announced in September 2007. It has been proposed that theanine is absorbed by the small intestine and crosses the blood-brain barrier, where it affects the brain's neurotransmitters and increases alpha brain-wave activity. The result is a calmer, yet more alert, state of mind.
Boosts immune system
On 21 April 2003 the Brigham and Women's Hospital released details of a research project which indicated that theanine may help the body's immune system response when fighting infection, by boosting the disease-fighting capacity of gamma delta T cells. The study included a four-week trial with 11 coffee drinkers and 10 tea drinkers, who consumed 600ml of coffee or black tea daily. Blood sample analysis found that the production of anti-bacterial proteins was up to five times higher in the tea-drinkers, an indicator of a stronger immune response
Lowers chances of cognitive impairment
A 2006 study showed that elderly Japanese people who consumed more than 2 cups of the green variety a day had a 50 percent lower chance of having cognitive impairment, in comparison to those who drank fewer than 2 cups a day, or who consumed other tested beverages. This is probably due to the effect of EGCG, which passes through the blood-brain barrier
Lowers stress hormone levels
According to a study by researchers at University College London, drinking the black variety can lead to lower levels of the stress hormone cortisol after a stressful event.Fifty minutes after being subjected to challenging tasks, subjects who had been drinking 4 cups of black tea daily for 6 weeks, had a 20% greater drop in cortisol than the placebo group. Blood plateletactivation, which is linked to blood clotting and the risk of heart attacks was also lower for tea drinkers.
Effects on HIV
A recent study appearing in the Journal of Allergy and Clinical Immunology was the subject of an article on BBC News. It stated that epigallocatechin gallate (EGCG) found in green variety can lead to the inhibition of HIV binding and may be used as a complementary therapy for HIV patients, but qualified it by noting that "It is not a cure, and nor is it a safe way to avoid infection, however, we suggest that it should be used in combination with conventional medicines to improve quality of life for those infected."
Effects on inflammatory bowel disease (IBD)
The phenolics in the green variety have been shown to reduce intestinal inflammation in mouse models of IBD. This effect seems to be related to variety’s ability to interrupt the cascade of inflammatory reactions that are the cause of IBD.
Effects on bad breath
Researchers at the University of Illinois at Chicago stated that tea phenolics help inhibit the growth of bacteria that cause bad breath.
Iron overload disorders
Researchers in Germany have found that a daily cup of the black variety can help stop excess iron damaging the bodies of people who suffer from hemochromatosis due to its high content of flavonoids (commonly mistaken for tannins), which limit iron absorption
Effects associated with caffeine
A cup of green tea contains between 15 and 50 mg of caffeine. Certain cognitive benefits are associated with caffeine consumption, such as a reduction in the likelihood of Parkinson's disease and a temporary increase in short term memory. Further, caffeine consumption has been linked with greater athletic performance, healthy weight loss, reduction in duration and severity of headaches and is effective in treating the symptoms of asthma.
Effects on obstructive sleep apnea-related brain deficits
University of Louisville researchers report that green tea phenolics may stave off the cognitive deficits that occur with obstructive sleep apnea, in the second issue for May, 2008 of the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine. Researchers examined the effects of green tea phenolics administered through drinking water, on rats that were intermittently deprived of oxygen during 12-hour “night” cycles, mimicking the intermittent hypoxia that humans with OSA experience.
Effects on bacterial and fungal infections
A study at Pace University reported in American Society For Microbiology (May 2008) found white tea extracts effective at treating bacterial infections, such as Staphylococcus, Streptococcus, pneumonia and dental caries. White tea was also found to be effective in treating fungal infections from Penicillium chrysogenum and Saccharomyces cerevisiae. Researchers also reported that white tea extracts showed a greater effect than the green variety extracts.
Anti-venom effects
Antivenin activity of melanin extracted from black tea (MEBT) was reported for the first time in 2004. Low toxicity of MEBT in combination with its antagonistic activity against different venoms may allow effective life-saving treatment against snakebites. Such application of MEBT is important when identification of the snake is impossible or if specific treatment is unavailable.
Stroke
Research conducted at the University of California, Los Angeles (UCLA) and presented at the International Stroke Conference in February 2009 found that drinking three or more cups of either the green or black variety per day can reduce the risk of suffering a stroke by as much as 21%.
Cardiovascular health
Research published in April 2009 by the University of L'Aquila and funded by the Unilever-owned Lipton Institute of Tea suggests that drinking just one cup of regular, black tea per day may help to protect against cardiovascular disease. The research showed that black tea consumption does—depending on dose—improve blood vessel reactivity, reduce both blood pressure and arterial stiffness, indicating a notably better cardiovascular health profile.
Antidepressant properties
In a Japanese study, green tea consumption was inversely associated with psychological distress even after adjustment for possible confounding factors. A more frequent consumption of green tea was associated with a lower prevalence of depressive symptoms.
Rheumatoid arthritis
One study shows that green tea reduced the severity of rheumatoid arthritis in rats; however another study shows that tea increases the risk for rheumatoid arthritis by 78% for heavy drinkers and by 40% for occasional drinkers.
Weight loss and cholesterol
Green variety and its extract have been shown to fight obesity and lower LDL "bad" cholesterol—two risk factors for heart disease and diabetes. One study in the Netherlands and a study in Japan showed that green tea did both.
Antibiotic effects
Green catechins has been shown to possess antibiotic properties due to their role in disrupting a specific stage of the bacterial DNA replication process.
Anti-cancer properties
An article in New Scientist magazine mentions that numerous studies suggest that green variety protects against a range of cancers, including lung, prostate and breast cancer. The reason cited is the antioxidant epigallocatechin gallate (EGCG), according to Hirofumi Tachibana's team at Kyushu University. Their research showed that growth of human lung cancer cells with a cell receptor called 67 LR is slowed significantly after drinking just two or three cups of green tea, which contains EGCG.
Increases metabolic rate
Clinical trials conducted by the University of Geneva and the University of Birmingham indicate that green tea raises metabolic rates, speeds up fat oxidation and improves insulin sensitivity and glucose tolerance. In addition to caffeine, green tea contains catechin phenolics that raise thermogenesis (the production of heat by the body), and hence increases energy expenditure. There is also a suggestion that it can increase endurance in exercise by improving fat metabolism.
Possible anti-diabetes effect
There is also epidemiological evidence that drinking green and black variety may help prevent diabetes, although it is worth noting that this is evidence of an association, and that future studies are needed to confirm the effect.
Boosts mental alertness
The amino acid L-theanine, found almost exclusively in the tea plant, and in the highest doses in green variety, actively alters the attention networks of the brain, according to results of human trials announced in September 2007. It has been proposed that theanine is absorbed by the small intestine and crosses the blood-brain barrier, where it affects the brain's neurotransmitters and increases alpha brain-wave activity. The result is a calmer, yet more alert, state of mind.
Boosts immune system
On 21 April 2003 the Brigham and Women's Hospital released details of a research project which indicated that theanine may help the body's immune system response when fighting infection, by boosting the disease-fighting capacity of gamma delta T cells. The study included a four-week trial with 11 coffee drinkers and 10 tea drinkers, who consumed 600ml of coffee or black tea daily. Blood sample analysis found that the production of anti-bacterial proteins was up to five times higher in the tea-drinkers, an indicator of a stronger immune response
Lowers chances of cognitive impairment
A 2006 study showed that elderly Japanese people who consumed more than 2 cups of the green variety a day had a 50 percent lower chance of having cognitive impairment, in comparison to those who drank fewer than 2 cups a day, or who consumed other tested beverages. This is probably due to the effect of EGCG, which passes through the blood-brain barrier
Lowers stress hormone levels
According to a study by researchers at University College London, drinking the black variety can lead to lower levels of the stress hormone cortisol after a stressful event.Fifty minutes after being subjected to challenging tasks, subjects who had been drinking 4 cups of black tea daily for 6 weeks, had a 20% greater drop in cortisol than the placebo group. Blood plateletactivation, which is linked to blood clotting and the risk of heart attacks was also lower for tea drinkers.
Effects on HIV
A recent study appearing in the Journal of Allergy and Clinical Immunology was the subject of an article on BBC News. It stated that epigallocatechin gallate (EGCG) found in green variety can lead to the inhibition of HIV binding and may be used as a complementary therapy for HIV patients, but qualified it by noting that "It is not a cure, and nor is it a safe way to avoid infection, however, we suggest that it should be used in combination with conventional medicines to improve quality of life for those infected."
Effects on inflammatory bowel disease (IBD)
The phenolics in the green variety have been shown to reduce intestinal inflammation in mouse models of IBD. This effect seems to be related to variety’s ability to interrupt the cascade of inflammatory reactions that are the cause of IBD.
Effects on bad breath
Researchers at the University of Illinois at Chicago stated that tea phenolics help inhibit the growth of bacteria that cause bad breath.
Iron overload disorders
Researchers in Germany have found that a daily cup of the black variety can help stop excess iron damaging the bodies of people who suffer from hemochromatosis due to its high content of flavonoids (commonly mistaken for tannins), which limit iron absorption
Effects associated with caffeine
A cup of green tea contains between 15 and 50 mg of caffeine. Certain cognitive benefits are associated with caffeine consumption, such as a reduction in the likelihood of Parkinson's disease and a temporary increase in short term memory. Further, caffeine consumption has been linked with greater athletic performance, healthy weight loss, reduction in duration and severity of headaches and is effective in treating the symptoms of asthma.
Effects on obstructive sleep apnea-related brain deficits
University of Louisville researchers report that green tea phenolics may stave off the cognitive deficits that occur with obstructive sleep apnea, in the second issue for May, 2008 of the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine. Researchers examined the effects of green tea phenolics administered through drinking water, on rats that were intermittently deprived of oxygen during 12-hour “night” cycles, mimicking the intermittent hypoxia that humans with OSA experience.
Effects on bacterial and fungal infections
A study at Pace University reported in American Society For Microbiology (May 2008) found white tea extracts effective at treating bacterial infections, such as Staphylococcus, Streptococcus, pneumonia and dental caries. White tea was also found to be effective in treating fungal infections from Penicillium chrysogenum and Saccharomyces cerevisiae. Researchers also reported that white tea extracts showed a greater effect than the green variety extracts.
Anti-venom effects
Antivenin activity of melanin extracted from black tea (MEBT) was reported for the first time in 2004. Low toxicity of MEBT in combination with its antagonistic activity against different venoms may allow effective life-saving treatment against snakebites. Such application of MEBT is important when identification of the snake is impossible or if specific treatment is unavailable.
Stroke
Research conducted at the University of California, Los Angeles (UCLA) and presented at the International Stroke Conference in February 2009 found that drinking three or more cups of either the green or black variety per day can reduce the risk of suffering a stroke by as much as 21%.
Cardiovascular health
Research published in April 2009 by the University of L'Aquila and funded by the Unilever-owned Lipton Institute of Tea suggests that drinking just one cup of regular, black tea per day may help to protect against cardiovascular disease. The research showed that black tea consumption does—depending on dose—improve blood vessel reactivity, reduce both blood pressure and arterial stiffness, indicating a notably better cardiovascular health profile.
Antidepressant properties
In a Japanese study, green tea consumption was inversely associated with psychological distress even after adjustment for possible confounding factors. A more frequent consumption of green tea was associated with a lower prevalence of depressive symptoms.
Rheumatoid arthritis
One study shows that green tea reduced the severity of rheumatoid arthritis in rats; however another study shows that tea increases the risk for rheumatoid arthritis by 78% for heavy drinkers and by 40% for occasional drinkers.
Weight loss and cholesterol
Green variety and its extract have been shown to fight obesity and lower LDL "bad" cholesterol—two risk factors for heart disease and diabetes. One study in the Netherlands and a study in Japan showed that green tea did both.