Scientists from Malaysia suggest that white tea demonstrates antioxidant, anticancer and DNA protective effects. A study originating from University of Malaya and published in Food Chemistry investigated the effects of white tea, specifically the premium Silver Needle variety, on the proliferation of colon cancer cell HT-29. In vitro testing found that high flavanoid and quercetin content displayed significant anti-proliferative properties against HT-29 cells, without being toxic to normal fibroblast cells. White tea extract was also found to protect the cell's DNA against oxidative H2O2 damage by up to 65%.
New research suggests that regular tea consumption lowers blood pressure and may help avoid hypertension. A Chinese meta-analysis of 25 randomized controlled trials published in the British Journal of Nutrition found that people who drank tea for more than 12 weeks lowered their systolic and diastolic blood pressure. According to researchers, high blood pressure can damage arteries, the heart, kidneys, eyes and other organs, so even a small decrease may have a meaningful contribution. The analysis also compared the effects of green and black teas and found that green tea showed most significant effects. Flavonoid compounds called catechins are thought to cause the effects, since they are known to improve the health of the inner lining of blood vessels.
New research suggests that regular tea and fruit consumption can significantly lower the risk of developing ovarian cancer. Scientists from UK's University of East Anglia found that women who consume foods and drinks high in flavonols, compounds that are found in tea, apples and grapes, were less likely to develop epithelial ovarian cancer. The large-scale study looked at the dietary habits of more than 171,000 women between the ages of 25 and 55 over a period of three decades and found that two daily cups of black tea were associated with a 31 percent reduction in risk. Previous research by Australian scientists indicates that a lifetime of tea drinking can cut the risk of ovarian cancer in old age.
Regular tea consumption was found to cut the risk of dying prematurely from causes unrelated to the heart by up to a quarter. The new large-scale study from France looked at tea and coffee intake of over 131,000 people aged 18 to 95 with low risk of cardiovascular diseases. Researchers found that tea consumption lowered the risk of non-cardiovascular death by 24% for smokers or ex-smokers. Tea also had a marked effect on blood pressure, with a significant reduction among heavy tea drinkers. Finally, tea intake was associated with increased physical activity among subjects.
A new study found that a combination of blueberry and green tea extracts might prevent illnesses associated with prolonged and intensive exercise, especially the upper respiratory tract infection. Experts looked into long-distance runners and how their blood coped with viral infections, a common risk following hard training. The study found that test subjects who were given a pill containing blueberry and green tea extracts had higher levels of gut-derived polyphenols in their blood, thereby reducing the risk of virus infections following rigorous exercise. The dose used in the study contained the equivalent of 3 cups of blueberries and 1.5 cups of green tea extracts per day.
A new review examining 39 previous studies concluded that tea consumption may lead to a noticeable reduction in breast cancer incidence and an improvement in blood vessel function. Researchers investigated thousands of breast cancer cases and found that regular green tea drinkers had a 21 percent decreased risk of breast cancer, most likely due to the high polyphenol content of green tea. The cardioprotective effects of black tea were also confirmed based on several studies that suggest a link between black tea flavanoids and improvement in blood vessel function.
Research suggests that people who drink at least one cup of herbal tea per week are at a lower risk of suffering from different types of colon cancer. Australian scientists investigated the effects of hot coffee, iced coffee, herbal tea, green tea and black tea on the risk of proximal colon, distal colon and rectal cancers. They found that the relationship between herbal tea consumption and decreased risk of bowel cancer was their most statistically significant finding. Researchers noted that the findings are a good starting point due to the accurate nature of pathology reports and beverages analyzed. However, they concluded that further studies are needed to investigate the protective factor of herbal tea.
Earl Grey, a blend of black tea and bergamot oil, may lower cholesterol levels and prevent heart disease. A team of scientists from Italy investigated bergamot, a Mediterranean citrus fruit and a key ingredient in Earl Grey tea, and its enzymes known as hydroxy methyl glutaryl flavonones (HGMF). It found that dietary supplementation of HMGF could be just as effective as statins in combating low-density proteins (LDL) or "bad" cholesterol. The enzymes were also shown to increase levels of high-density lipoproteins (HDL) or "good" cholesterol. The findings about the cholesterol-reducing effects of bergamot are consistent with a 2012 Italian study.
Jawbone, a technology company, launched a new smartphone app that tracks daily caffeine intake with the aim of predicting its long-term effects on sleep. The idea is a result of data crunching of 1600 Jawbone's customers who use a wearable band to track physical activity and nutritional intake throughout the day. It found that users do not always get enough sleep due to the ubiquity of smartphones, email and high caffeine intake. The new app allows users to log each caffeine intake from coffee, tea, energy drinks or even chocolate, and then calculates their alertness from "wired" to "sleep ready". After tracking users' caffeine intake for 10 days, the app is able to estimate how much sleep is lost due to caffeine.
Research shows that high intake of tea is associated with a decreased risk of arterial stiffness, which is linked to several types of heart disease. Scientists from Taiwan investigated the relationship between tea consumption and arterial wall thickening in more than 3,000 subjects over a period of one year. They found that subjects who drank more than 450ml of tea per day, which is equivalent to 3 cups, had a 22 percent cut in measurements of arterial stiffness, which is a predictor of heart attack, heart failure and stroke. Flavonoids found in tea are thought to open up the blood vessels and reduce arterial stiffness by augmenting nitric oxide production. The results held true for all types of tea, including black and green.
A new study published in the journal Nature Neuroscience suggests that a dose of caffeine may enhance certain memories at least a day after they were formed. According to the research team, it's the first time that a study looks into the impacts of caffeine on long-term memory. It analyzed 160 participants and their capacity to remember old, new and similar pictures the following day. Some were given a pill containing either 200mg of caffeine, roughly equivalent to 5 cups of tea, or a placebo tablet. Researchers found that subjects who were given caffeine were better at identifying similar pictures, compared to those who were given a placebo. According to scientists, the brain's ability to recognize the difference between two similar but not identical items reflects a deep level of memory discrimination.
A recent review of medical studies suggests that moderate daily intake of caffeinated beverages such as tea does not harm children and may even have beneficial effects. While increasing consumption of caffeinated beverages by young children and adolescents stokes fears of negative repercussions on their health, this systemic review of 13 observational studies and official guidance on caffeine consumption from several countries claims that caffeine is unlikely to be harmful when consumed in moderation. In fact, the review cites a study that found that caffeine intake in low doses actually improves performance on attention and motor task tests in children. The results suggest that younger children may safely consume up to two daily cups of tea and older school aged children can consume up to three cups of tea a day.
A new Canadian study suggests that some supermarket teas contain amounts of lead that could potentially pose a health threat to pregnant and nursing mothers. Researchers from the University of Alberta analyzed samples of 30 commonly sold teabags and found excessive amounts of lead in 73% of teas brewed for three minutes. The authors clearly state that these findings may only apply to pregnant women who consume three to four cups of tea a day, and are not relevant to non-pregnant adults. Teas grown in China were found to contain higher levels of lead than those harvested in India and Sri Lanka. Surprisingly, organic teas showed the highest levels of lead. The cause of these findings remains unclear, but one possibility is that China's widespread use of coal in power plants may play a role.
Recent studies published in a supplement of the American Journal of Clinical Nutrition confirm some of the key health benefits associated with tea consumption. 12 new articles by world-renowned scientists explore how tea may reduce risk of certain cancers, promote weight loss, improve bone health and activate areas of the brain that bolster attention, problem solving and mood. For example, in a double-blind, placebo-controlled study, green tea polyphenols were shown to reduce the progression of prostate cancer in men. Another study looked at cardioprotective features of black tea and found that it reduced blood pressure, and among hypertensive subjects, helped counteract the negative effects of a high-fat meal on blood pressure and arterial blood flow. Finally, psychological effects of tea were also under the scope: 2-3 cups were shown to improve mental alertness and mood. The studies were hailed as a significant advancement of research into tea and human health.
A professor from Montana State University received a $931,000 grant from the National Science Foundation to investigate links between tea quality and changing weather conditions. The grand will fund research into how long-term changes in weather and precipitation patters may affect the healthfulness of tea crops. Preliminary research indicates that antioxidant content may decrease by as much as 50% with the onset of heavy rains, also called monsoons, in tea producing countries. The study will focus on samples from multiple locations in China to determine how eroding weather conditions impact the content of certain substances associated with health benefits of tea. An interdisciplinary team of researchers will be funded for four and a half years.
Many health claims related to tea are linked to its antioxidant content. ConsumerLab, an independent nutritional testing lab, measured levels of the most abundant catechin found in tea, epigallocatechin gallate (EGCG), in more than two dozen green tea products. Tested items covered hot teas, iced teas and nutritional supplements. Of the 14 products that listed levels of EGCG on the label, only three contained significantly less than the amount claimed, including Honest Tea Green Tea with Honey, which had only about two-thirds of the 190 milligrams of listed catechins. EGCG content among products without labeling was more varied: Teavana's Green Tea Gyokuro Imperial had 86 milligrams of EGCG per serving, whereas one bag of Bigelow Green Tea contained only 25 milligrams. 200 milligrams of EGCG is the recommend daily intake. It takes hot water 3 to 5 minutes to fully extract the EGCG from the tea leaves.
Researchers from the UK claim that drinking black tea may help keep teeth in good condition by preventing tooth decay and gum disease. A review of existing studies focused on tea's ability to combat two types of bacteria – Streptococcus mutans and Lactobacillus – and concluded that three to four daily cups reduced their respective levels in the mouth. Compounds found in tea and known as flavanoids and catechins appear to reduce inflammation. They actually prevent the growth of bacteria that start a chain reaction with carbohydrates to produce acid, which then dissolves enamel. Similar effects were observed for green tea, which was also found to have the potential to aid weight loss by boosting energy expenditure and burning up more fat.
New research suggests coffee and tea may protect from liver disease. An international team of scientists found that increased caffeine intake may reduce fatty liver in people with non-alcoholic fatty liver disease. Caffeine is reported to stimulate the metabolization of lipids stored in liver cells and decrease the fatty liver of mice fed a high-fat diet. According to researchers, the equivalent of four cups of coffee or tea per day may be necessary to prevent non-alcoholic fatty liver disease in humans. 70% of all people diagnosed with diabetes and obesity have the liver disease, which remains the major cause of fatty liver not due to excessive alcohol consumption.
Men who drink more than 5 cups of tea per day are much less likely to suffer from advanced stages of prostate cancer, Dutch research suggests. The study, which analyzed data on 58,279 men and 3,362 cases of prostate cancer, compared flavonoid intake from food and drinks with subjects' health records. It reveals that drinking 5 cups of tea per day is associated with a 25% lower risk of developing stage II of the disease. Furthermore, male tea drinkers are less likely to reach the terminal stage IV of prostate cancer by 33%. There is no indication that milk, sugar, lemon or other sweeteners reduce these beneficial effects.
A new study found that people who regularly drink tea or coffee have lower blood pressure compared to those who do not. The large-scale study by the Preventive and Clinical Investigations Centre in Paris monitored the blood pressure of 180,000 people aged 16 to 95 for 10 years. Those who drank more than 4 cups of tea or coffee per day had the lowest blood pressure reading and also had the lowest pulse pressure and heart rate. People who did not drink tea or coffee recorded the highest blood pressure, pulse and heart rate readings. While the differences were small, they were statistically significant. According to scientists, flavonoids found in tea may be responsible for relaxing the blood vessels. High blood pressure is a risk factor for heart disease, heart attack and stroke.
An Australian study suggests that black tea consumption may substantially reduce the rate of blood pressure variation. The article, published in the American Journal of Clinical Nutrition, claims that drinking three cups of black tea a day alters blood pressure variation by about 10 percent. A sudden fluctuation in blood pressure can be an early warning sign of a stroke or even heart disease. Furthermore, the study used a flavanoid-free caffeine-matched beverage in the control group, which means that the results do not stem from caffeine, but from another component in black tea. The positive results of drinking black tea were noticeable from the first day and continued over the course of the six-month study.
A chemical study found that tea, coffee and certain other plant-based foods seem to activate a gene associated with cancer. Researchers at John Hopkins Medicine discovered that green and black teas, coffee, bread crusts, cocoa powder and liquid smoke might cause DNA damage equivalent to chemotherapy drugs. They focused on a gene called p53, which is activated when DNA damage occurs, and found that those ingredients increased the activity of p53 30-fold. While scientists are unsure what causes these effects, they suspect that plants contain compounds that are meant to deter humans and animals from eating them, like cellulose in stems and bitter-tasting tannins in leaves and beans.
A large-scale study identified a reduced risk of stroke among green tea and coffee drinkers in Japan. Over 80,000 Japanese adults were followed for an average period of 13 years and those who drank four cups of green tea or a cup of coffee per day benefited from a decreased risk of stroke of 20%. Five or more cups of green tea corresponded to a 15 percent decrease in all-cause mortality, and a 26 percent decrease in dying from cardiovascular disease. Green tea drinkers' risk of intracerebral hemorrhage was also reduced by 32 percent. Although exact reasons behind the results remain unclear, scientists suspect that antioxidants are responsible for the majority of the beneficial effects.
A recent study found that drinking tea and coffee, both rich in certain antioxidants, may not lower the risk of suffering from dementia or having a stroke. The findings are at odds with several other studies that claim that a diet high in antioxidants helps reduce the risk of dementia and stroke. Researchers studied the antioxidant intake of approximately 5,400 subjects over a period of 14 years, with the vast majority of antioxidants coming from tea and coffee. They found no correlation between the consumption of those beverages and a decreased risk of dementia or stroke. This may indicate that specific antioxidants present in fruits or vegetables may be more effective in fighting off certain diseases than those coming from tea or coffee.
Breakthrough research suggests that green tea may be able to prevent the spread of Alzheimer's disease in the brain. A new study from the UK found that a compound abundant in green tea called epigallocatechin galate, or EGCG, is able to disrupt a key step of Alzheimer's disease pathway, preventing it from progressing. EGCG was shown to neutralize the effects of a specific type of protein that latches on to nerve cells in the brain and ultimately causes those cells to die. The antioxidant altered the shape of the protein compounds, preventing them to attach to the nerve cells. Scientists claim this is an important new lead in the search for new and effective treatments for this yet incurable disease.
Scientists from the UK have discovered that green tea compounds called catechins may help protect the skin against sunburn and the long-term effects of UV damage. The study was performed on 14 healthy human subjects with fair skin and involved taking green tea catechin supplements for 12 weeks. The dose was roughly equivalent to two cups of green tea. The effects of the supplements were tested before and after supplementation by exposing buttock skin to UV rays and quantifying the level of sunburn. The results demonstrate that catechins may contribute to skin protection against sunburn inflammation and potentially longer-term damage caused by UV rays, and may therefore be a complement for sunscreen.
Scientists found that tea made from coffee plant leaves may be healthier than tea or coffee. The brew, which tastes less bitter than tea and not as strong as coffee, has less caffeine than tea or coffee, but contains high levels of compounds that lower the risk of diabetes and heart disease. Research from the UK and France suggests that brewed coffee plant leaves shelter more cancer-fighting antioxidants than tea or coffee and contain high levels of mangiferin, which is believed to have anti-inflammatory effects. Mangiferin is also known to lower blood cholesterol and protect neurons in the brain. The infusion is already being consumed in places such as Ethiopia, South Sudan and Indonesia.
Women who start drinking tea at a younger age have been found to benefit from a lower risk of ovarian cancer later on in life. A study surveyed tea-drinking habits of 1000 women with an average age of 59 over a period of two years. Data included daily consumption, tea type and when they first started. Results showed that women without cancer were more likely to be tea drinkers from an earlier age and, on average, consumed more cups a day than those diagnosed with the illness. Authors of the study suspect that flavonoids may be responsible for these effects and encourage the consumption of tea because of the potential benefit in preventing this common and deadly disease.
According to research backed by Unilever, owner of Lipton and PG Tips tea brands, countries that have a higher consumption of black tea also display a significantly lower prevalence of diabetes among their populations. Scientists studied black tea consumption in 42 countries and compared it to data from the World Health Organization on each country's rates of respiratory, infectious and cardiovascular diseases, as well as cancer and diabetes. They found that, on average, a population that consumes double the amount of black tea has about one quarter less cases of diabetes. Ireland had the highest annual consumption at more than 2 kilograms per person, closely followed by the UK and Turkey. South Korea, Brazil, China, Morocco and Mexico were at the bottom of the list. Researchers admit that this study does not establish a cause and effect relationship between the two variables, but claim that the scope of the study and the robust statistical relationship will pave the way for further research.
A large-scale study suggests that green tea may play a role in lowering risks of colon, stomach and throat cancers for older women. Scientists from Vanderbilt University School of Medicine in Nashville followed 69,000 women for a period of ten years and found that those who drank green tea at least three times a week were 14 percent less likely to develop a cancer of the digestive system. Furthermore, the study found that women who drank green tea for at least 20 years were 27% less likely than non-drinkers to develop any digestive system cancer. Although researchers admit only clinical studies can establish a direct link, they did account for other factors like diet, income, exercise habits and medical history in their study and still found a benefit of drinking green tea.
A study that was presented at the conference of American Association for Cancer Research suggests that green tea may slow the progression of prostate cancer. Drinking six cups of brewed green tea was shown to lower the levels of some disease-associated inflammation. The study focused on 67 prostate patients scheduled for a type of surgery known as a prostatectomy, where the prostate is removed, and found that drinking tea in preceding weeks produced a noticeable drop in both serum prostate-specific antigen (PSA) concentrations and PSA protein expression. Researchers explain that reduction in inflammation may be an indication that green tea may also inhibit tumor growth. The study builds on previous research that suggests that flavonoids may be associated with a lower risk of developing prostate cancer.
A new lab study has found that green tea extracts may be able to destroy skin cancer cells. The University of Strathclyde team discovered that a compound found in green tea called epigallocatechin gallate, or EGCG, is able to either prevent skin tumors from growing, shrink them or even make them disappear. After one month of treatment, 40% of tumors of one type of human skin cancer were entirely removed, whereas a further 30% shrank during the same period. One reason for these successful results may be the fact that, for the first time, EGCG compounds were delivered directly to the tumors using specific proteins that target tumors' receptors for different biological substances.
New research suggests that compounds found in green tea and chocolate may help prevent cognitive impairment experienced by patients with HIV. A study by a research team at Johns Hopkins University discovered that plant polyphenols known as catechins found in green tea might be responsible for encouraging survival and growth of neurons in the brain. Catechins seem to stimulate the production of brain-derived neurotrophic factor, which is a protein that is active in areas of the brain vital to learning, memory and higher thinking. HIV patients have lower levels of this protein compared to healthy individuals. The fact that catechins easily cross the blood-brain barrier increases their therapeutic potential and offers hope of the first neuroprotective treatment for cognitive impairment for people with HIV.
An urologist has warned that high consumption of iced tea, especially during the summer months, may contribute to the formation of kidney stones. According to assistant professor at the Department of Urology at Loyola University Chicago Stritch School of Medicine, iced tea contains high concentrations of oxalate, one of key chemicals that leads to the formation of kidney stones. Because many people choose to drink iced tea instead of water in the summertime, individuals who have a tendency to form the most common type of kidney stones are specifically at risk. Despite the fact that hot tea contains similar amounts of oxalate, it is difficult to consume sufficient amounts to cause kidney stones since 85% of tea consumed in the US is iced.
Data from Linus Pauling Institute suggests that green tea and grape seed extracts may act as plant-based alternatives to control blood sugar levels. They appear to inhibit actions of specific enzymes that are responsible for carbohydrate digestion, thereby controlling sugar levels and reducing the risk of suffering from cardiovascular or neurological complications. Scientists suspect that a specific catechin present in tea and grapes, called Epigallocatechin gallate or EGCG, may be responsible in large part for beneficial effects. Four percent of Europe's population, or 19 million peolpe, suffer from illnesses associated with type 2 diabeted. In the US, almost 24 million people live with diabetes, equal to 8 percent of the pupulation.
Data from Linus Pauling Institute suggests that green tea and grape seed extracts may act as plant-based alternatives to control blood sugar levels. They appear to inhibit actions of specific enzymes that are responsible for carbohydrate digestion, thereby controlling sugar levels and reducing the risk of suffering from cardiovascular or neurological complications. Scientists suspect that a specific catechin present in tea and grapes, called Epigallocatechin gallate or EGCG, may be responsible in large part for beneficial effects. Four percent of Europe's population, or 19 million peolpe, suffer from illnesses associated with type 2 diabetes. In the US, almost 24 million people live with diabetes, equal to 8 percent of the pupulation.
A recent study found that regular tea consumption is associated with a reduction of several risk factors that may lead to heart disease. First, it was discovered that three daily cups of tea over a period of 12 weeks lead to a significant reduction in blood sugar levels and triglycerides, which are unhealthy fats. Triglyceride levels fell by 39 percent in male participants and 29 percent in females. Furthermore, drinking tea increases the levels of HDL cholesterol, also known as the "good" type. Finally, the study suggests that tea increases the amount of antioxidants present in the blood stream, which can protect blood vessels and tissue against oxidative stress and inflammation. The tea that was tested contained no sugar or milk, as the latter may reduce the availability of polyphenols.
A study of European populations found that drinking tea was an effective way of reducing the risk of developing type 2 diabetes. It discovered that countries whose citizens are heavy tea consumers and drink at least four cups of tea per day have a 20 per cent lower risk of developing the illness. German scientists working on the study suspect that this beneficial effect may be caused by polyphenols contained in tea. They may lower the risk of type 2 diabetes by influencing glucose digestion, glucose uptake, and by protecting beta-cells from free-radical damage. The research was carried out in 8 European countries and included over twelve thousand type 2 diabetes cases. Average European tea consumption ranges from four daily cups in the UK to none a day in Spain.
A recent study from Harvard Medical School suggests that consumption of flavanoids could help prevent the formation of blood clots in arteries and veins. Flavanoids are compounds commonly found in fruits, vegetables and tea. According to researchers, a popular flavanoid called rutin has the potential to prevent and treat stroke and heart attacks, as well as deep venous thrombosis and pulmonary embolism. It acts by inhibiting clot formation both in arteries and in veins, which possesses different features in both cases, thereby enabling a single agent to prevent both types of clots. Scientists plan to follow up on these findings with a clinical trial.
Canadian researchers have received an additional $157,000 grant to study cancer-fighting properties of dandelion root extract. The grant now totals $217,000 and will be used by the University of Windsor to advance research about the efficiency of dandelion root extracts in killing cancerous cells. Scientists were spurred by findings that dandelion root extract forced a very aggressive and drug-resistant type of blood cancer cell to essentially commit suicide. They tested the formula on leukemia cells and discovered that it caused those cells to kill themselves, without affecting healthy cells. The majority of the grant is provided by the Lotte and John Hecht Memorial Foundation.
A large-scale study by Harvard University and the University of East Anglia found that flavanoid consumption significantly decreases the risk of developing Parkinson's disease among men. Flavanoids are a type of antioxidant found in berries, red wine and tea. The study, conducted on 130,000 people during a 20-year period, revealed that the highest consumption of flavanoids is associated with a 40% decrease in risk of developing Parkinson's disease. The findings, which focus on anthocyanin, a type of flavanoid, only hold true for men, as women did not benefit from the positive effects. Parkinson's disease is a progressive neurological condition affecting one in 500 people.
Women who regularly drink tea are more likely to get pregnant than those who don't and those who prefer soft drinks. The study, conducted by scientists from Boston University on 3,600 women, focused on the link between caffeine intake and fertility. It found that women who drank two cups of tea per day were 27% more likely to become pregnant. Coffee drinkers did not experience the same effect, whereas those who drank two soft drinks per day seemed to witness the opposite effect: their chance of pregnancy fell by 20%. While this research seems promising, experts caution that further studies are needed to conclusively prove the link and establish which elements in tea are actually responsible for this.
Latest findings suggest that green tea kills bad breath thanks to its antioxidant content. Israeli scientists found that polyphenols, a type of antioxidant found in green tea, destroy compounds in the mouth that are responsible for bad breath, tooth decay and mouth cancer. Polyphenols called epigallocatechin 3 gallate (EGCG) possess properties that can abolish bad breath by modifying sulphur components responsible for halitosis. They can also fight harmful effects of smoking by reducing oral cavities, oxidative stress and inflammation caused by cigarettes. There is an increasing interest among the scientific community in green tea as a proponent of oral health.
A recent review published in UK's Nutrition Bulletin found that regular consumption of black tea protects against cardiovascular complications and type 2 diabetes. Three cups of black tea per day, with or without milk, can reduce the risk of heart problems by cutting levels of bad cholesterol (LDL) and blood sugar. Two or more cups a day may protect against type 2 diabetes. Scientists attribute these beneficial effects to flavanoids, a type of antioxidant found in tea that fights excessive pro-oxidant free radicals in the body. One typical cup of black tea contains 150-200mg of flavanoids. In addition, a 12-week study of 87 volunteers found that drinking three cups of tea a day produced a significant improvement in various cardiovascular risk factors.
A major Japanese study has found that senior citizens who regularly consume green tea are more agile and active than non-tea drinkers. Almost 14,000 individuals aged 65 and over took part in the three-year experiment. Scientists focused on whether green tea drinkers have a lower risk of frailty and disability as they grow older. They found that those who consume at least five cups of green tea per day were one-third less likely to develop "functional disability", or problems with daily activities, such as dressing or bathing. Even after adjusting for confounding factors such as diet and lifestyle habits, the link was deemed significant. Although reasons behind the findings remain unclear, researchers point to a study that suggests that green tea extracts seem to boost leg muscle strength in older women.
The South African Rooibos Council, an industry body, has granted over $250,000 to fund further research on potential health benefits of rooibos tea in 2012. The organization seeks scientific evidence on soothing, healing, disease-prevention and weight-loss properties of rooibos, a bush cultivated only in South Africa. The grant also covers studies on anti-aging, anti-obesity and cancer-preventing properties of rooibos tea, and the role of rooibos in performance during exercise and post-exercise recovery. Previous studies indicate that rooibos tea may alleviate stress and anxiety, as well as prevent skin cancer and other diseases.
An Australian study found that people who drink three cups of black tea a day can lower their blood pressure by 2 to 3 points. According to researchers, although the reduction may seem small, it has a significant effect on the prevalence of high blood pressure and the risk of heart disease. The observed decrease in blood pressure is equivalent to a 10% reduction in the prevalence of both conditions and can have a major impact on risk factors behind heart disease and death. The study was performed over a period of 6 months on 95 regular tea drinkers. Previous research suggests that possible explanations for the findings may include improved interior lining of blood vessels and reduced body weight and abdominal fat achieved by regular black tea consumption.
German researchers have found that a flavanoid, or one of the active ingredients in green tea, inhibits hepatitis C virus from entering the liver, following a transplant. For patients receiving transplants due to complication from hepatitis C, the antioxidant called epigallocatechin-3-gallate, or EGCG, may prevent the reinfection of the healthy donor liver. The World Health Organization estimates that up to 170 million people worldwide are affected by hepatitis C, which is one of the most common causes of chronic liver disease and a primary indication for liver transplantation. The antioxidant EGCG was found to possess antiviral properties and inhibit the rapid spread of hepatitis C.
A US study suggests that green tea may reduce LDL, or "bad" cholesterol by a few points. It shows that green tea catechins, taken in a capsule or drunk in the form of tea, may trim 5 to 6 points more from people's total cholesterol and "bad" LDL cholesterol levels. Brewed green tea was more effective than capsules, though the benefits overall were fairly small. The drink did not show any effectiveness in boosting "good" HDL cholesterol, or cut triglycerides, another type of blood fat. The trials that lasted between three weeks and six months involved over 1400 adults who were randomly assigned to either use green tea every day, as a beverage or capsule, or be part of "control" groups that used placebo capsules or liquids.
A medical study from Japan shows evidence of a clear link between green tea consumption and reduced odds of catching the influenza virus. Scientists studied the effects of green tea on influenza in 2600 kids and found that children who drank five cups of green tea per week had significantly fewer cases of flu, compared to those who drank almost no green tea. Children who drank about one cup of green tea per day also had significantly fewer sick days from school. Green tea compounds catechins and theanine were found to enhance systemic immunity and interfere with viral replication. In fact, the results were so conclusive that scientists established that regular consumption of green tea is protective against influenza infections during the influenza season.
Scientists have discovered a novel way to fight Alzheimer's disease using a mix of green tea and red light. The laser light pushes water out of the cells and when the laser is switched off, the cells absorb water and any other molecules, including drugs, from their surroundings. The combination of green tea and red laser light was found to destroy Alzheimer's plaques that crowd the brains of people with the disease. Researchers from Germany bathed brain cells with EGCG, an extract found in green tea, while stimulating the cells with red light. This method reduced the amount of plaques that cause loss of memory and other symptoms by 60 percent.
A new trial in Germany is aiming to find out whether green tea can prevent colon cancer. The study will investigate the effects of green tea on the formation and recurrence of colon polyps, sometimes seen as precancerous. According to the authors behind the study, it is the biggest of its kind in the world. It will rely on 3000 participants and results should be available after six years. Scientists will focus on the effects of plant hormone epigallocatechin 3-gallate (EGCG), which was shown to inhibit the formation of tumors of the prostate, breast and uterus. The dosage will be equivalent of about five to ten cups of tea, depending on the method of preparation. The project, which costs €2.1 million ($2.8 million), is entirely sponsored by a German non-profit organisation.
A review of studies on health benefits of green and black teas found that both are equally effective. Both varieties come from the same plant, camellia sinensis. The difference is how the leaves are processed: green tea leaves are steamed and dried, while black tea leaves are fully oxidized. According to the researcher, studies that have looked at those two types of tea have confirmed similar improvements in vascular function, leading to significant reductions in stroke risk. The average intake in those studies was 4 cups per day for black tea and 5 to 6 cups per day for green tea (due to the smaller cup traditionally used). The study was commissioned by the UK Tea Advisory Panel.
Tea and coffee drinkers are less likely to carry the methicillin-resistant Staphylococcus aureus (MRSA) in their noses. MRSA is a superbug that is resistant to antibiotics and may cause severe diseases in people with weak immune systems. According to a study from Medical University of South Carolina, drinking either beverage reduces the risk of carrying MRSA by about 50%, whereas drinking both is associated with a 67% decline. While the study did not establish a causal relationship between tea and nasal MRSA carriage, authors of the study suggest that antimicrobial properties of tannic acid and catechins may be responsible. Iced tea drinkers did not benefit from same effects as hot tea drinkers.
Research from the University of South Florida reveals new insights on how green tea may help prevent Alzheimer's disease. The study shows that tea-based flavonoids and other bioactive chemicals like Epigallocatechin-3-gallate and luteolin help improve in vitro some biomarkers associated with Alzheimer's. While flavonoids have already been known to be helpful against the disease, this was the first study to identify how they correct dysfunctions in cells' energy-producing structures. According to researchers, the results of this study lend further credence to the notion that EGCG and other flavonoids can be described as "multipotent therapeutic agents". Five million Americans may live with Alzheimer's disease, according to the National Institute on Aging.
Two new studies have revealed new mechanisms by which tea could help in cancer prevention. In one study, researchers from New Jersey studied theaflavin-2, a compound found in black and oolong teas. They discovered that it activates genes that kill cancer cells, while simultaneously reducing molecules responsible for inflammation. The second study from India examined the effects of tea polyphenols on the development of breast cancer in female rats. They found that black and green tea polyphenols significantly lowered the number of mammary tumours by 77% and 92% respectively, and reduced their growth. These findings shed new light on the ability of tea components to regulate genes and reduce inflammatory mechanisms.
An Australian biomedical professor has discovered that green tea, onions and olive leaf extract can combat obesity and associated diseases like diabetes, heart disease and fatty liver. And this holds true even for diets high in fats and carbohydrates. Tests on rodents showed that green tea helped prevent the growth of inflammatory cells in the animals' fat pads, located in the abdomen, which take fat from the blood stream and store it. The rodents' liver and heart function also saw improvements. The flavanoid responsible for these effects is called rutin. It reversed or prevented metabolic changes in rats that had been fed a diet high in sugar and fat.
A new study suggests that green tea, when combined with a fitness activity known as tai chi, may improve bone health and reduce inflammation in postmenopausal women. Tai chi is a Chinese martial art known for its slow movements. Scientists at Texas Tech University probed the potential for green tea to work synergistically with tai chi in enhancing bone strength. The six-month, double-blind, placebo-controlled, intervention trial involved 171 postmenopausal women with a median age of 57. It found that women who consumed an equivalent of four to six daily cups of green tea and participated in tai chi showed enhanced bone health and increased muscle strength after six months. The combination of green tea and tai chi also had a substantial effect on biological markers of oxidative stress, which is a precursor to inflammation.
New research suggests that tea can help lose weight, although adding milk neutralizes this ability. Scientists have identified two compounds, theaflavins and thearubigins, which help reduce the amount of fat absorbed by the gut and can cut cholesterol. However, if milk is added to the cup, its proteins cancel out these beneficial effects. British researchers have gone further and found that the type of milk added also matters. Skimmed milk decreases the levels of active compounds present in tea far more than whole or semi-skimmed milk. Scientists believe this can explain why the British people do not benefit from positive effects of tea despite being heavy consumers.
Scientists are reviewing scientific data to establish the health benefits of herbal infusions. The US Department of Agriculture has requested a study of the potential health benefits of the three most popular herbal teas. After reviewing previous studies, scientists noted that chamomile tea has moderate antimicrobial activity and significant antiplatelet-clumping activity. Peppermint tea has been found to have significant antimicrobial and antiviral activities. Finally, hibiscus tea is thought to lower blood pressure. And while these studies were not carried out on humans, researchers concluded that there is enough evidence to suggest further clinical studies.
According to a study carried out by Dutch scientists, drinking tea improves brain performance and reduces tiredness. The research focused on caffeine and L-theanine, an amino acid found in tea, and discovered that their combination can prove beneficial in improving cognitive performance. The effects were tested on a group of 44 young volunteers using various mental tasks like word recognition and attention switching. The speed and accuracy of these tasks were significantly improved by the active ingredients, compared to the placebo group. Scientists also found that drinking tea reduced tiredness and fatigue in the group. The research was conducted on behalf of Unilever, the owner of Lipton tea brand.
The current issue of Food Technology magazine claims that tea, coffee and low-fat milk surpass sports drinks and enhanced waters when it comes to nutrition and workout recovery. Evidence suggests that physically active individuals who regularly consume tea experience accelerated body-fat reduction and increased endurance and recovery. Scientists also point out that coffee, the primary source of antioxidants in the US diet, is packed with polyphenols and actually has a higher antioxidant content than tea or fruit and vegetable juices. Milk is thought to aid in weight management and weight loss, accelerating the loss of body fat around the waistline.
A scientist team from the UK claims that regular green tea consumption could protect the brain against dementia and could also help prevent certain forms of cancer. The study centers around the finding that chemicals created when tea is digested are more effective against triggers of certain diseases than undigested form of the tea. The anti-cancer properties of these digested compounds protect the cells, preventing the toxins from destroying them. Although scientists working on the project admit that many factors influence diseases like dementia and cancer, they recommend to drink at least one cup of green tea per day.
Latest research from Japan suggests that tea may prevent weight gain caused by a diet rich in fats. In a study on mice, regular green or black tea consumption suppressed body weight gain and the build-up of belly fat linked to a fatty diet. Furthermore, scientists found that black tea, the most popular variety in many Western countries, counteracts symptoms associated with the onset of type 2 diabetes, such as increases in cholesterol, high blood glucose and insulin resistance. Rising obesity levels in Western countries have resulted in many more people having insulin resistance. Experts hope that these findings can be confirmed in studies on humans.
Scientists say that regular consumption of polyphenol-rich drinks can boost astringent sensations and our sensitivity to acids. They have also discovered that varying levels of polyphenols are already stored in the saliva - with huge differences between green tea or red wine drinkers and non drinkers. The study found that regular tea drinkers are more sensitive to astringency in acid solutions, which means that more polyphenol compounds are stored in their saliva. Given that the liquid in the saliva comes from the blood, it indicates that there may be a long-term build-up of polyphenols inside our blood system. This may help explain "the French paradox" - the observation that French people have a relatively low incidence of heart disease, despite their diet rich in saturated fats.
A large study from Japan has found no significant link between green tea consumption and reduced risk of breast cancer. Nearly 54'000 women were questioned about their green tea intake and researchers found no difference in breast cancer rates between women who consumed the most green tea and women who drank the least. The findings call into question in vitro and animal-based studies that have suggested that green tea may have beneficial protective effects against the disease. Animal studies have suggested that the polyphenols and antioxidants found in green tea may be protective against cancer, including breast cancer. Breast cancer remains one of the most common cancers among American women.
Researchers linked regular coffee and tea intake to a steep reduction in glioma, a type of brain tumor. A study of 410'000 European citizens during a period of eight and a half years found that drinking about a half cup or more of coffee or tea per day was associated with a 34% reduction in risk of suffering from glioma. The research was not designed to establish a causal effect, but a potential connection was observed from questionnaires about coffee and tea intake. Male drinkers benefited from a greater reduction than women. Tea consumption was highest in the UK and lowest in Spain. Scientists believe that antioxidants found in tea may explain the protective effect.
Researchers at the University of Western Australia have found that drinking three cups of tea a day can protect against heart attacks and strokes. Their wide-ranging study, which did not find any difference between green and black varieties, suggests that regular tea consumption can reduce the risk of cardiac problems by 11 percent. Flavonoids, a type of antioxidant, are thought to cut the formation of plaque - a combination of fat an cholesterol - in the arteries. Two cups of tea are equivalent to five portions of vegetables in terms of antioxidant delivery.
During the National Breast Cancer Awareness month scientists have highlighted the health benefits of green tea on the metabolism of overweight breast cancer survivors. A recent study from University of Arizona suggests that drinking decaffeinated green tea helps breast cancer survivors improve metabolic biomarkers. Overweight breast cancer survivors who drank decaffeinated green tea reduced their energy intake leading to some weight loss and improved their good cholesterol levels. Each year 175'000 women are diagnosed with breast cancer in the US and 50'000 die from the disease. Authors of the study note that being overweight after breast cancer treatment may increase a woman's risk for recurrent disease and early onset cardiovascular disease.
Coffee and tea drinkers may have a decreased likelihood of developing the most common form of malignant brain tumor in adults, a new study suggests. A study of 500'000 adults in Europe linked higher coffee and tea intake to a lower risk of gliomas, a group of brain tumors that makes up about 80 percent of malignant brain cancers in adults. People who consume more than a cup of tea or coffee per day were one-third less likely to be diagnosed with glioma, with factors such as age and smoking history taken into account. However, scientists conceded that the reasons behind these findings remain unknown, because little is understood about what actually causes brain cancer.
Scientists from the UK and Spain have discovered a compound found in green tea that inhibits the growth of cancer cells. The joint in vitro study confirmed that naturally occurring polyphenol EGCG prevents cancer cells from growing by binding to a specific enzyme, thereby stopping this enzyme from making DNA. According to scientists, this helps explain decreased rates of certain cancers in regular tea drinkers. Concentrations used in the test are equivalent to those found in the blood of people who drink 2 or 3 cups of green tea a day. Researchers hope that this breakthrough will lead to new anti-cancer drugs based on the structure of the EGCG molecule.
The Food and Drug Administration has issued stern warnings to two large beverage manufacturers for making unsubstantiated health claims about their green tea drinks. Canada Dry Sparking Green Tea Ginger Ale, owned by Dr. Pepper Snapple Group, and Unilever's Lipton Green Tea drinks were found to make claims that do not follow agency's guidelines. Food processors increasingly have been adding vitamins and nutrients to their products to make them more appealing to health-conscious consumers. However, the FDA considers that the soft drinks, categorized as food snacks, do not meet federal requirements to claim antioxidant or disease-preventing properties. The FDA generally endorses health claims on foods only after government researchers have verified that the products help prevent actual disease.
Comparing brewed and bottled tea, scientists have discovered that home-made versions have more antioxidants than bottled ones. The experiment found that brewed tea contains between 50 and 150 mg of polyphenols, whereas bottled tea holds anywhere from 81 to 3 mg of polyphenols per 16oz. (500ml) unit. Researchers say that polyphenol content in bottled teas is extremely variable and low due to added sugar and high dilution, in an attempt to keep bitterness and astringency low. Authors of the study warn that polyophenol levels on labels of bottled teas may not be correct because of lack of government regulations for measuring and listing the compounds.
A new report by the US Department of Agriculture has reaffirmed the link between carbonated soft drink consumption and obesity. This puts further pressure on the beverage industry, whose previous strategies have not yielded sufficient results. Furthermore, the USDA report endorses the idea of taxing beverages with high levels of sweeteners that may lead to excess weight. It estimates that a 20% tax on sweetened beverages could result in "savings" of 38 calories per day for the average American, adding up to 3.8lbs (2kg) weight reduction per year. Experts say that even though the reduction in caloric intake from such an initiative would be relatively small, it may lead to a change in consumer behavior with long-term effects on health and medical bills.
Scientists have discovered that black tea contains far more fluoride than previously thought. Early studies suggested that black tea had 1 to 5 milligrams of fluoride per liter, but a new study by Medical College of Georgia found that the beverage can hold up to 9 milligrams of fluoride. A couple of daily cups is thought to prevent dental cavities, yet high intake or long term ingestion can lead to bone health problems. According to the study, it is safe to consume 2 to 3 milligrams of fluoride per day (through water, toothpaste and food), whereas ingesting 20 milligrams per day for more than 10 years may lead to serious bone deficiencies.
People who regularly drink tea are less likely to suffer from memory loss later in life, according to a new study. Researchers from the University of California in Los Angeles have established a link between tea consumption and cognitive function in individuals over 65 years old. Data from over 4800 senior citizens shows that regular tea consumption reduces the likelihood to develop memory problems by 17 to 37 percent. Scientists working on the study point out that the protective effect is unlikely to be linked to caffeine, and suggest that it may be attributed to flavonoids or theanine contained in tea. The research was supported by the Lipton Institute of Tea.
A Dutch study has found that daily tea intake can significantly lower the risk of dying from a heart disease. In one of the largest and longest studies ever, researchers followed more than 37,000 people for 13 years in order to establish the impact of tea and coffee on heart health. It turns out that people who drank three to six cups of tea per day had a 45% lower risk of death from heart disease than people who drank less than one cup of tea a day. The association held up even when other lifestyle factors associated with heart disease, including smoking and exercise level, were taken into account. Scientists believe that antioxidants called flavonoids found in tea and other beverages and "super foods" may explain the protective effect seen in the study.
In a breakthrough study, American researchers have figured out how polyphenols contained in green tea and red wine inhibit cancer growth. The experiment, carried out on mice genetically altered to develop a human prostate cancer tumour, shows that green tea compounds EGCG and polyphenol E disrupt a specific cell-signaling pathway that is often responsible for cancer growth. The finding is important because it may lead to the development of drugs that could stop or slow cancer progression, or improve current treatments. Scientists working on the study are convinced that as long as they are taken in moderation, tea and wine may be ranked among the most potent 'health foods'.
Scientists from Australia announced a study that indicates that drinking tea may lead to a reduction of the risk of ovarian cancer. The study looked at food and lifestyle habits of about 2700 women, half of whom had a history of ovarian cancer. Total tea intake emerged as the key factor, as women who drank four or more cups of tea per day were linked with a 30 percent reduction of the risk of ovarian cancer. It is interesting to note that the decrease in risk is associated with all varieties of tea (black, green and herbal) and there was no added benefit from drinking green tea. Although the reasons for the findings remain unclear, scientists suspect that antioxidants in tea are responsible for these effects.
Green tea extracts may be instrumental in reducing cancer cells in the blood of patients with a form of leukemia and may slow the progression of the disease. According to findings from Mayo Clinic in the US, two thirds of patients in the early stages of the most common form of leukemia showed a significant reduction in the number of leukemia cells in their blood. The active ingredient is epigallocatechin galeate (EGCG), an antioxidant found abundantly in green tea and already associated with many beneficial effects. Although these findings will require more research to confirm the results, the lead author of the study believes this non-toxic treatment may be useful for stabilizing this form of leukemia and potentially slowing it down.
Scientists from Chinese Academy of Sciences have found a way to use tea to inhibit nicotine addiction. They identified theanine, an amino acid commonly found in tea, as an active ingredient to help reduce addiction to cigarettes with better efficacy and fewer side effects. The study, carried on over 100 male smokers, found that the participants' average daily cigarette consumption decreased by about 50% after using filters containing theanine for one month, with additional drops in consumption after prolonged use. Toxicological studies also showed that the tea filters could significantly reduce the intake of carcinogenic materials such as tar and free radicals generated by cigarette smoking.
A research paper suggests that drinking green tea increases dental health. Researchers found that people aged 40 to 64 who drank one cup of green tea a day were less likely to lose teeth. They found that men who drank at least one cup of tea a day were 19% less likely to have fewer than 20 teeth than those who did not drink green tea. Tea drinking women had 13% lower odds. Scientists suspect that antimicrobial molecules called catechins present in green tea and, in lesser amounts in other tea varieties, kill mouth bacteria associated with tooth decay and gum disease.
A study, conducted by researchers at the University of Washington, has revealed that consumption of black or green tea on a daily basis reduces the risk of ovarian cancer. It analyzed the lifestyle of around 2000 women in different professions. One daily cup of green tea was shown to reduce the risk of suffering from ovarian cancer by 54 percent. Antioxidants found in tea are thought to be responsible for stalling cancer cell growth by substantially reducing the production of numerous proteins that are believed to promote the cells’ survival. Ovarian cancer is the fifth most common cancer among women and fourth leading cause of deaths in women due to cancers.
Latest research has confirmed that green tea may protect against glaucoma and other eye diseases. Scientists have found that green tea catechins, known for their antioxidant properties, penetrate into tissues of the eye and are absorbed by the lens, retina, and other tissues. In a study on rats, it was shown beyond a doubt that eye structures absorbed significant amounts of individual catechins and that the effects in reducing harmful oxidative stress in the eye lasted for up to 20 hours.
Latest research shows that men who drink at least two cups of tea per day have slimmer waistlines than those who drink coffee or nothing at all. The study, which examined links between tea and coffee consumption and obesity among 3,823 adults in the US, also noted that men who use sugar in their tea have smaller waistlines compared to men who use artificial sweeteners. The benefits of drinking tea did were not found among women. However, the exact connection between tea and a thinner waistline isn't exactly understood.
According to a new study by London's Imperial College, drinking at least five cups of coffee or tea every day could help prevent brain tumors. Scientists, analyzing over 300 cases of glioma brain tumor in men and women, found that people who consumed five or more cups of coffee or tea a day had a 40% smaller chance of developing the cancer. Men benefited more from the protective effects of caffeine, although the exact cause of that could not be pinpointed. Decaffeinated tea or coffee was not associated with the same benefits.
A Chinese review of studies found that tea may help prevent endometrial cancer. The researchers noted that an increase in tea consumption of two cups per day was associated with a 25% reduced risk of developing the disease. The association was significant for green tea, but not for black tea. Endometrial cancer - which forms in the lining of the uterus - is the fourth most common cancer in American women. The National Cancer Institute says there are 42,000 new cases in the United States each year, and nearly 7,800 deaths.
Drinking green tea may offer some protection against lung cancer, according to Taiwanese scientists. In as study of more than 500 people, they discovered that among smokers, those who did not drink green tea at all were more than 12 times as likely to develop lung cancer than those who drank at least a cup a day. Researchers also analyzed the DNA of people in the study and found certain genes appeared to play a role in the risk reduction.
Japanese scientists have found that green tea has the potential to cut the risk of developing depression among elderly people. Tohoku University researchers discovered that 44% of elderly men and women studied were less likely to have depression symptoms if they drank four or more cups of green tea daily. The researchers established the link even after considering such factors as social and economic status, gender, diet, history of medical problems, and the use of antidepressants. There was not a similar effect found with other teas, such as black or oolong tea, or coffee.
An Australian study found that regular tea and coffee consumption lowers the risk of developing type II diabetes. In a review of 18 studies including more that 450000 people, scientists noted that drinking three to four cups of tea each day lowered their risk of diabetes by about twenty percent, whereas three to four daily cups of coffee accounted for a 25 percent reduction in the risk of developing the disease. The beneficial effects include better blood sugar regulation and insulin secretion. They are believed to stem not from caffeine, as previously thought, but from other components, such as magnesium, lignans and chlorogenic acids.
A UK study suggests that Brazilian mint tea has pain relieving qualities to match those of commercially available analgesics. Research, which was carried out on mice, indicates that when the mint was given at a dose similar to that prescribed by traditional healers, the medicine was as effective at relieving pain as a synthetic aspirin-style drug called Indometacin. Scientists plan to launch clinical trials to find out how effective the mint is as a pain relief for people.
Research carried out by scientists form University of Texas found green tea may prevent the onset of oral cancer. Subjects with pre-malignant lesions were given green tea extracts, equivalent to eight to ten cups of tea, and were more clinically responsive than those given the placebo. Although at the end of the two-year study period there was no difference in oral cancer development overall between those who took green tea and those who did not, patients who presented with mild to moderate dysplasia had a longer time to develop oral cancer if they took green tea extract.
A large scale study in Japan reveals that green tea can relieve stress from overworking. The study was carried out on over forty thousand individuals and found that green tea was beneficial for those who suffered from psychological stress. Those who drank five cups of green tea per day showed considerably less psychological distress than those who drank less than a cup a day. These results were calculated after making adjustments for variables such as age, diet, cigarette smoking, alcohol consumption and disease histories.
Drinking up to eight cups of tea a day may offer significant health benefits, according to a dietician from London's King's College. A review of 47 published studies suggests that a daily intake of 400mg of caffeine, equivalent to eight cups, delivers key benefits in terms of mental function and heart health without any adverse consequences. The scientist found that regular tea drinking could help lead to reduced mortality, a lower risk of heart attack and lower cholesterol.
Researchers at University Medical School in Arizona are looking for test subjects to participate in a study on green tea's potential in preventing the human papilloma virus, a virus that can lead to cervical cancer in women. Previous experiments have shown that green tea extract helps clear up cervical lesions created by the virus. The goal of the study is to see if more women who receive treatment with Polyphenon E, a chemical present in green tea, clear the HPV than those receiving the placebo.
Japanese scientists have found that green tea helps women reduce the risk of suffering from pneumonia. According to the study, drinking 5 cups or more of green tea daily has shown to cut the risk by up to 47%. However, even small amounts of green tea have a positive impact, researchers say. Drinking as little as one cup of tea or less per day was associated with a 41% decrease in risk.
A new study by Japanese scientists has shown that green tea may prove highly beneficial for health and cut down the risk of developing blood cancer. Drinking 5 cups of tea per day was found to slow down the growth of cancer-causing viruses and micro-organisms. The study, carried out on more than forty thousand adults in Japan, suggests that those who regularly consume 5 cups of green tea have 42% lower chances of developing all types of blood cancer than those who drink one or fewer cups of the green tea.
A human trial studying the relationship between green tea and body weight has found that men receiving catechin-enriched green tea showed a significant reduction in body weight, waist circumference and body fat as compared to men given catechin-depleted green tea. Average weight loss in catechin-enriched group was 5.3 lbs (2.4 kg), as compared to 2.9 lbs (1.3 kg) in subjects ingesting catechin-depleted product. In a separate study, scientists discovered that consumption of green tea catechins increased energy expenditure, by boosting the total amount of fat burned at rest and increasing the total number of calories burned on a daily basis.
Scientists at the National Cancer Center in Tokyo examined six studies involving links between tea consumption and stomach cancer, and noted a 20 percent decrease in stomach cancer risk for women drinking 5 or more cups of green tea per day. The results remain true, even when smoking was taken into account. However, the researchers found no correlation between tea drinking and stomach cancer among men.
According to a new Chinese study, funded by Lipton Institute of Tea, regular consumption of green tea was shown to promote weight loss and improve body composition in moderately overweight individuals. This study analyzed the effects of green tea consumption on body weight, body fat mass, as well as the distribution of fat. It found that body weight, waist circumference, intra-abdominal fat and the total lean mass all decreased after 90 days in the group that drank the tea with the highest concentration of catechins, equivalent to 6 to 10 daily cups of green tea.
Scientists from Hong Kong have found that chemicals in green tea may help strengthen bones by stimulating their formation and slowing the process of weakening them. In a laboratory experiment on rat cells, they have noted that the ingredient epigallocatechin (EGC) in green tea boosted the level of a key enzyme that promotes bone growth by nearly 79 percent. Also, they found that EGC increased the density of bone minerals in the cells, thereby reducing the risk of pain and fracture.
A study from Scotland and France indicates that green and black tea may lower the risk of heart disease by preventing fatty deposits from building up in arteries. The research, carried out on hamsters with a high-fat diet, found a "remarkable" reduction in fatty build-ups of up to 96%. Scientists believe similar effects can be replicated in human trials, as the administered amounts were equal to a cup of tea per day. The protective effect apparently comes from plant-derived chemicals known as phenolic compounds and flavonoids found in tea and some juices.
A study from Purdue University found that including sucrose and vitamin C in ready-to-drink green tea beverages may boost their health profile. Research suggests that adding sugar and vitamin C increases the absorption of green tea compounds, epigallocatechin (EGC) and epigallocatechin gallate (EGCG), by up to 200%. A separate study from Hong Kong has recently discovered that the cells of regular tea drinkers may have a younger biological age than cells from non-drinkers - difference being about 5 years of life.
American Heart Association has issued guidelines on daily sugar consumption aimed at cutting sugar intake drastically from current levels. An average American consumes 22 teaspoons of sugar each day, whereas the new guidelines suggest 6 teaspoons for women and 10 for men. The guidelines include added sugar, commonly found in soft drinks, candy, cakes, and cookies. Some of the most common added sugars are corn sweetener, corn syrup, dextrose, glucose, high fructose corn syrup and honey. The biggest source of extra sugar in a typical diet are soft drinks and other sugar-sweetened beverages.
Latest study from Kingston University in the UK suggests white tea reduces age-associated wrinkles. Results showed white tea prevented the activities of the enzymes which breakdown elastin and collagen which can lead to wrinkles that accompany aging. The findings also indicate that white tea reduces the risk of inflammation which is characteristic of rheumatoid arthritis and some cancers.
Scientist found that tea-making can reduce stress levels by up to a quarter. The findings reveal that even a single cup of tea can significantly reduce anxiety levels after suffering a stressful experience. Moreover, psychologists discovered that the act of putting the kettle on also helped by tapping into a collective conscious and symbolism. The study showed a 25% increase in anxiety for those that did not receive tea immediately after the stress-inducing test, whereas those who were given tea actually demonstrated a four per cent reduction in stress.
According to a study published in Journal of Food Science, black tea has the potential of managing the development of diabetes. Chinese scientists, examining the polysaccharide levels of different tea varieties, found that polysaccharides in black tea had the most glucose-inhibiting properties. Polysaccharides are a type of carbohydrate that may benefit people with diabetes because they help retard absorption of glucose. Black tea polysaccharides are also shown to have the highest scavenging effect on free radicals, which are involved in the onset of diseases such as cancer and rheumatoid arthritis.
Japanese scientists discovered that prolonged consumption of tea could weaken bones due to high content of toxic fluorine. Particularly black and oolong tea are known to hold large amounts of the substance. According to the study, tea beverages contain up to 70% more fluorine than standard tap water, which typically has 0.8 milligrams per liter. Researchers concede that there is no immediate risk to human health, yet they call for a standard to be set and displayed on tea-based products in order to reduce the risk of bone rupture.
A wide ranging new Cochrane review of studies that examined the affects of green tea on various cancers, including breast, lung and prostate, has yielded conflicting results. The review, compiling 51 studies that included more than 1.6 million participants and were conducted from 1985 through 2008, found that green tea alone couldn't account for cancer prevention in most cases. Researchers believe further studies are needed to investigate its health benefits, yet remain optimistic about green tea's potential to fight off certain types of the disease.
Scientists have discovered that a spray made from green tea could offer powerful protection against skin cancer. Researchers from Cleveland, Ohio say the tea spray has the capability to enhance skin's in-built immune system and reduce the damage caused by sun's ultraviolet light. It is believed that this blend can not only protect the skin, but prevent cellular damage that leads to skin cancer. Antioxidants known as polyphenols are thought to explain these beneficial effects.
Findings of a recent study into the effects of green tea on prostate cancer found that certain compounds have an influence on the progression of the disease. The studied substance, polyphenon, was found to significantly reduce the serum markers predictive of prostate cancer progression. In collaboration with Columbia University in New York City, the researchers are currently conducting a comparable trial among patients with breast cancer.
Scientists from Arizona are conducting a clinical study to analyze if green tea can help prevent cervical cancer. The research, funded by the National Cancer Institute, is testing a green-tea extract's effect on viruses that can cause cervical cancer in hopes of finding the first non-surgical way of preventing the disease. The group of viruses, commonly known as HPV, is the most common sexually transmitted infection in the United States, with an estimated 20 million people carrying the virus.
In a new study, Australian scientists have found that frequent tea consumption can significantly reduce the risk of suffering a stroke. Researchers discovered that long-term consumption of green tea, at least once a week, substantially decreases ischemic stroke risk. The study looked into green tea consumption of Chinese patients who suffered a stroke and found encouraging news when comparing frequent drinkers with infrequent or nondrinkers. Major inverse dose-response relationships were also found for years of drinking and the amount of dried tea leaves brewed.
Scientists found that high doses of a chemical found in green tea could kill cancer cells and reduce symptoms of leukemia, a blood or bone marrow cancer. Preliminary results suggest that humans are tolerant to very high doses of an active ingredient in green tea, epigallocatechin gallate (EGCG), and that many trial patients saw a regression of the disease. Researchers believe that the treatment would not be potent enough on its own, but could make other anti-cancer treatments like chemotherapy more successful.
A green tea compound is found to inhibit sexual transmission of HIV virus when used as an ingredient in vaginal creams. German researchers discovered that the green tea polyphenol, called epigallocatechin-3-gallate (EGCG), is capable of neutralizing a protein in sperm which serves as a vector for viral transmission during sex. Scientists believe that EGCG could provide a simple and affordable prevention method for poor and developing nations, and would also enable women to ensure proper protection during sexual intercourse.
White tea, made from the youngest and most tender buds of the plant, is capable of breaking down fat cells and preventing new ones from forming, according to latest research. Scientists from Germany tested extracts of white tea on human fat cells and found that they reduced the amount of genes associated with the growth of new fat cells and prompted existing cells to break down the fat they contain. In the US, a third of the population is categorized as obese, compared to a quarter in the UK.
Researchers from the University of Missouri-Columbia found that chemicals in tea produce consistent, biologically safe gold nanoparticles, which show promising anticancer properties. Scientists discovered that nontoxic formation of gold nanoparticles can be achieved by adding gold salts to a simple cup of tea. Gold nanoparticles have many potential medicinal and technological uses, such as targeted anticancer drugs, but currently their synthesis needs toxic reagents that make them unsuitable for use in the body. The natural chemicals used in this new method are harmless in the body and produce no toxic byproducts.
A study published in Clinical Nutrition suggests that green tea may help people lose weight by enhancing the feeling of satiety and preventing hunger. 27 persons were subject to three weeks of negative and three weeks of positive energy balance, during which bioactive ingredients such as capsaicin and green tea were ingested on 10 separate test days while the effects on appetite, energy intake, body weight and heart rate were assessed. The Danish study indicates that a combination of capsaicin and green tea may be helpful in reducing energy intake and might support weight loss periods by relatively sustaining satiety and suppressing hunger.
According to latest research, women who drink a few cups of tea or coffee each day benefit from a lower risk of endometrial cancer, which arises in the lining of the uterus. Women who drank more than two cups of tea per day had a 44 percent lower risk of the disease, caused mainly by older age, obesity and higher levels of estrogen. Scientists point to caffeine as a possible explanation, as it induces certain enzymes that help neutralize potentially cancer-causing substances in the body. Underscoring this theory was also the absence of any link between decaffeinated coffee and cancer risk in the study.
A new study suggests a link between caffeine intake during pregnancy and heart growth and cardiac function later in life. The experiment, carried out on mice, showed that even small amounts of caffeine delivered during development may negatively impact the heart. While the preliminary findings may not be directly relevant to human health or disease, they shed light on the question of prenatal caffeine exposure, as approximately 60 percent of women say they have consumed coffee during the first month of pregnancy.
New research on antioxidant activity in commercially available green tea bags reveals steep drops take place within the first six months if products remain unopened and unexposed to light or moisture. Scientists, who analyzed eight teas sold in different countries, discovered a slight drop-off in catechin antioxidant content early on in the storage process, and went on to observe a significant decline of 32% by the end of six months. They hope this preliminary study will prompt more research into the antioxidant storage conditions.
Yerba mate tea, made from a shrub widespread in South America, is causing discord among scientists regarding its health benefits. While the plant contains many vitamins, minerals and antioxidants, experts caution on comparisons with green tea. A recent review of existing studies confirmed that people who regularly drink large amounts of the tea, as much as a liter or more each day, had significantly increased risk of cancers of the esophagus, lungs, mouth, pharynx and larynx. Although the studies remain inconclusive, researhers urge to enjoy yerba mate in moderation.
Iranian scientists have discovered that drinking steaming hot tea may increase the risk of oesophageal, or food tube, cancer. They found that drinking black tea at temperatures of 70C (158F) or higher increased the risk of cancer in the muscular tube that carries food from the throat to the stomach. Compared with drinking warm or lukewarm tea (65C or less), drinking very hot tea (70C or more) was associated with an eight-fold increased risk. Oesophagus cancers kill more than 500,000 people worldwide each year and oesophageal squamous cell carcinoma (OSCC) is the most common type of the disease.
A study of eating habits among Chinese women found that mushrooms and green tea have the potential to cut breast cancer risk by up to 90 percent. Women who ate at least 10g (0.3 oz.) of fresh mushrooms daily were 64% less likely to develop breast cancer. And those who combined mushrooms with green tea saw an even greater risk reduction. Researchers suspect chemicals in the foods block tumor growth and boost the body's natural defenses against cancer.
Latest research suggests tea and coffee really do taste better from a favorite cup or mug. Scientists from the UK found that a person's brain is trained to believe the daily ritual of making coffee or tea should be done in a certain way in order to derive maximum enjoyment. The study indicates that caffeine is a drug of reward and people develop preferences as to how the drug is delivered. According to research, 65 percent of British have a favorite cup or mug they use for their morning cuppa.
New research suggests that green tea can improve the health of teeth and gums. The study, carried out on 940 men in Japan, found that people who regularly drank green tea had very healthy teeth and gums, compared to those who did not routinely drink it. According to research, the anti-inflammatory effects of green tea catechins reduce the risk of periodontal disease - less bleeding with probing, decreased depth of periodontal pocket and decreased clinical loss of attachment of tooth to gum.
A study by the University of Southern California found that green tea may negate the effects of bortezomib, a drug used for treatments of certain types of blood cancer. The cancer drug, sold under the brand name Velcade, is said to be countered by green tea polyphenols, and could be entirely blocked by green tea supplements, containing up to 50 times as much polyphenol as a single cup of tea. Velcade is used to treat multiple myeloma, the second most common blood cancer.
The European Union has announced plans to crack down on foods that advertise health benefits without scientific backing. The EU has decided claims must be based primarily on human clinical trials. Animal studies can be used, with a few exceptions, only as supporting evidence. Moreover, the evidence must in most cases be "convincing," not merely plausible. The EU's rules are the strictest in the world, industry experts say, and may affect food giants such as Danone and Nestlé, as well as hundreds of smaller manufacturers.
The second annual HealthSaver Caffeinated Cities Survey analyzed 20 metropolitan cities in the United States to rank them based on overall levels of consumption of caffeine, as well as specific categories, with regard to coffee, cola, tea, sweets containing chocolate, pain relievers, energy drinks, and caffeine pills. The Tampa / St. Petersburg / Clearwater area of Florida ranked first in the United States, after having come in second in the 2007 survey. Seattle ranked second in 2008, though when broken down into the coffee category alone, the city ranked a solid first. According to the survey, tea represents 20% of the overall caffeine intake.
Research from Finland suggests coffee and tea consumption in midlife may protect against the risk of dementia and Alzheimer's disease later on in life. The study tried to look at the long-term impact of caffeine on the central nervous system, as the pathological processes leading to Alzheimer's disease are believed to start decades before the clinical manifestation of the illness. Although the findings need to be confirmed by other studies, they point towards the possibility that dietary interventions could modify the risk of these diseases.
According to new research, people who consume tea, wine or chocolate have higher brain performance than those who do not. An international team of scientists examined the relation between cognitive performance and the intake of those three substances. They found that those who consumed chocolate, wine, or tea had significantly better mean test scores and lower prevalence of poor cognitive performance than those who did not. The active ingredients studied were flavonoids, micronutrients found in plant-derived foods.
A study on the effects of drinks on teeth has found that brewed tea possesses much less negative erosive properties compared to other soft drinks. According to research published in General Dentistry journal, tea poses virtually no risk to the hard part of teeth, or enamel, whereas refined sugars and acids found in soda and citrus juice promote tooth erosion, which is irreversible. Academy of General Dentistry spokesperson has therefore highly recommended patients to choose tea as an alternative to more erosive drinks like soda and fruit juice.
Scientists at the Medical College of Georgia found that green tea antioxidants may slow or even prevent the development of type 1 diabetes. The study, carried out on laboratory mice, tested the effects of green tea's predominate antioxidant, known as EGCG, on type 1 diabetes and Sjogren's syndrome, which damages moisture-producing glands causing dry mouth and eyes. It was discovered that the antioxidant compound reduced the severity and delayed the onset of salivary gland damage associated with Sjogren's syndrome - a condition with no known cure. EGCG also dramatically slowed the development of type 1 diabetes in the rodents.
According to a recent study, drinking hibiscus tea lowered blood pressure in a clinical trial of 65 pre-hypertensive and mildly hypertensive adults, aged 30 to 70 years. For six weeks, about half the group was randomly selected to drink three cups of hibiscus tea daily while others drank a placebo beverage containing artificial hibiscus flavoring and color. The findings show that the volunteers who drank hibiscus tea had a 7.2 point drop in their systolic blood pressure, compared to a 1.3 point drop in the volunteers who drank the placebo beverage. The study was co-sponsored by Celestial Seasonings tea company.
According to recent research, drinking chamomile tea daily may help prevent the complications of type 2 diabetes, such as loss of vision and nerve and kidney damage. In laboratory tests on rats, UK and Japanese scientists found that chamomile extract appears to cut blood sugar levels and block activity of an enzyme associated with the development of diabetic complications. Scientists cautioned that further research would be needed to confirm the plant's role in fighting diabetes-related complications, yet noted that the study raised hopes of a new anti-diabetes drug.
The first-ever human clinical trial on the effects of rooibos tea on the cardiovascular system was carried out in South Africa. The research, conducted by a group of scientists from the Cape Peninsula University of Technology, shows that short-term consumption of rooibos tea is safe for the liver and kidneys while keeping various blood parameters in a normal range. Provisional results from the study indicate that "red bush" tea protects the body against oxidative damage, as seen by the 21 percent decrease in conjugated dienes in the blood.
A new study has found that greet tea catechins encapsulated in nanoparticles may be released in a controlled manner. In vitro research showed that chitosan nanoparticles had an encapsulation efficiency of over fifty percent and thus a controlled release of antioxidant-rich polyphenols was achievable. Nanotechnology is already being used in food and packaging industries and focuses on altering matter at an atomic or molecular scale. A more effective delivery system could pave the way for a more widespread use of green tea catechins.
Research from the University of Singapore shows that drinking two to three cups of tea a day can halve the risk of early signs of dementia. In a study of lifestyle habits of 2,500 people aged 55 and over, it was found that sipping through a couple of cups of black tea per day can cut the risk of cognitive decline by 55%, and up to 63% for heavy tea drinkers. According to scientists, no protective effects on the brain were noted for caffeine, which indicates that polyphenols found in tea were responsible for increased brain function. It is believed that polyphenols prevent oxidation of brain cells and block build-up of plaques in the brain.
A new study by a group of Swedish scientists suggests that coffee and tea consumption may reduce the risk of stroke caused by a blockage. The study, carried out on over 26,000 Finnish male smokers, examines ties between diet and risks of different types of strokes caused by bleeding in the brain and artery blockage. The results show that men who drink two or more cups of tea per day have a 21% lower risk of this type of stroke compared to non-drinkers. Scientists suggest tea's phenolic compounds may be instrumental in preventing cerebral infarction and hope to confirm the results among women and non-smokers.
A Brazilian study measuring the effects of green tea on athletes undertaking resistance training indicates that its consumption increases body's antioxidant defense capacity. Researchers say that if the results can be confirmed on a larger scale, the antioxidant-rich beverage could be proven valuable in fighting oxidative damage caused by exercise. The findings may pave the way for green tea to gain access to the energy drinks market, which is valued at £137 million in the UK and almost $3 billion in the US.
Researchers in Egypt found that green tea enhances the effects of antibiotics up to threefold in fighting drug-resistant bacteria. The study, carried out by the Alexandria University, suggests that in almost every case and for all types of antibiotics they tested, drinking green tea at the same time as taking the antibiotics appeared to increase the action of the antibiotics and reduce drug resistance in bacteria.
A study, published in the American Journal of Clinical Nutrition, suggests that green tea can not only prevent heart diseases, but also help to burn fat. The authors of the study found that green tea extracts increased the rate at which the body metabolizes fat, enhancing the amount of generated energy by up to 17 percent.
A recent French study suggests that women who drink three or more cups of tea per day reduce their exposure to heart attacks and strokes. The study examined the thickness of plaques in blood vessels, which are build-ups of fat or cholesterol and are linked to an increased risk of heart complications, and found those plaques were less frequent with increasing tea consumption in women. Strangely, no benefits were recorded among women who drank less than three cups of tea a day or for men.
Latest research from the University of Dundee, Scotland suggests that black tea may help prevent type 2 diabetes, which develops when the body fails to produce enough insulin. The researchers have discovered that several components of black tea, namely theaflavins and thearubigins, mimicked insulin action and could have beneficial effects on the most widespread form of the disease.
An Australian study suggests that drinking tea may help strengthen hips in older female patients. Patients who drank about three cups of tea per day showed a higher bone density compared to non-drinkers. Antioxidant flavanoids are believed to contribute towards bone mineral density by a stimulatory effect on new cells that build bone. Hip fractures and osteoporosis remain a major cause of disability for older women.
A new laboratory study suggests that EGCG, one of the main components of green tea, is a powerful medicine against severe sepsis, an abnormal immune system response to a bacterial infection. Researchers found that a dose equivalent to ten cups of green tea raised the survival rate in mice by nearly 30%. The findings could pave way to clinical trails in search for a cure for a disease that is known to cause death in half of medical cases.
DSM Nutritional Products, the world’s leading producer of vitamins and carotenoids, has developed a patented process to further purify green tea extracts. This process permits concentration of the most important active principle of green tea, EGCG. EGCG is the most abundant catechin in green tea, and most of the scientifically validated health effects are attributed to this constituent. DSM offers this extract under the brand name TEAVIGO as an ingredient for foods, beverages and supplements. The company claims that while TEAVIGO contains the major benefits of pure green tea, it does not significantly alter color and taste of the food or beverage.
A new mechanism has been found that might explain green tea's protective effects against cancer. A "promiscuous chaperone protein" has been discovered - so-called because it binds to many different cells and receptors in the body-known as hsp90, is involved in conferring green tea's protective effects.
A new study conducted by researchers at the University of Scranton suggests that tea might prevent diabetes and its ensuing complications, including cataracts. This new research has found that both green and black teas have been shown to decrease glucose levels which, in turn, affects other biochemical pathways that accelerate diabetic complications such as cataracts.
A recent Chicago College of Dentistry study showed that people who rinsed their mouths with black tea multiple times a day had less plaque buildup than those who rinsed with water. "Polyphenols in tea suppress the bacterial enzyme that triggers plaque accumulation," says Christine D. Wu, Ph.D., the lead study author. "Drinking tea a few times a day could have the same effect."
In contrast to previous research and the FDA, the American Institute for Cancer Research study found that a substance in green tea intercepts one of the proteins that activate cancer cells in some cases, stopping the process at an earlier stage than researchers assumed. The study results were published in the April issue of Biochemistry, a peer reviewed science journal.
Drinking black tea reduces LDL and total cholesterol, and it may do more. Researchers in Japan have found black tea also improves blood flow. They measured the coronary flow velocity reserve (CFVR) of men given various types of hot drinks. The CFVR indicates the amount that blood flow can speed up when demands are put on the heart. CFVR improved two hours after drinking black tea.
For centuries tea drinkers have sipped chamomile for relief from problems ranging from colds to menstrual cramps to jet lag. Now, scientists are beginning to investigate how chamomile works. A study at Imperial College London found recently that the tea raises the body's levels of hippurate, a substance that increases antibacterial activity. Chamomile also increases glycine, an amino acid that relieves muscle spasms. The beneficial effects of chamomile appear to last for as long as two weeks after drinking it.
Green tea, already lauded for its cancer-fighting ability, may also protect against certain autoimmune diseases, new research suggests. Green teas inhibit the expression of antigens made by the body, substances that can trigger an immune response, explained study author Stephen Hsu, an associate professor in the School of Dentistry at the Medical College of Georgia in Augusta. While the research is very preliminary, eventually green tea might help protect cells from being attacked by the autoantigens.
Among many other steps and practices, the National Center for Chronic Disease Prevention and Health Promotion (a branch of the Centers for Disease Control), recommends people trying to quit tobacco drink tea instead of coffee.
Research team from Michigan State University claims tea is the major source of flavonoid antioxidants in the U.S. diet, supplying roughly 55 percent of the estimated 134 mg consumer per/day in the U.S. diet. Other major food groups contributing to flavonoid intake include fruits, vegetables, and various carbohydrates (bread, cereal, rice and pasta). It is thought that any health effects from tea drinking may stem from its naturally occurring antioxidant content. "For most Americans, drinking a cup of tea a day -- hot or cold -- will increase their daily flavonoids by over 50 percent. This in turn, may further reduce risk for chronic diseases," said Douglas Balentine, Ph.D., Director Nutrition Sciences, Unilever Health Institute.