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Tea News: Green Tea Protects Skin Grafts Preserving donated human tissue until it can be used for transplants is difficult. However, new research has shown that green tea polyphenol antioxidants (for example, EGCG) can improve preservation in a variety of tissues, including blood vessels, corneas, nerves, heart cells, pancreas cells, and cartilage. A new preliminary study tested skin grafts on animals both with and without green tea polyphenols for up to 8 weeks. The skin grafts were successful with green tea preservation for up to 7 weeks when kept at 4 degrees C. (39.2 F, or slightly above freezing) but were not successful when preserved at that temperature without green tea polyphenols. All skin tissue kept at 37 degrees C (98.6 F) were unsuccessful regardless of green tea polyphenols (Kawazoe T, Green tea polyphenols affect skin preservation in rats and improve the rate of skin grafts, Cell Transplantation, 2008). Improving the preservation of tissue for transplants could help parts of the world with less reliable capacity for freezing, or during emergency situations. Tea News: Green Tea, White Tea, Black Tea, And A Parasite A protozoa parasite called Trypanosoma brucei is transmitted by the tse-tse fly and can cause fatal sleeping sickness in people. Currently, there are an estimated 50,000 to 70,000 cases, primarily in sub-Saharan Africa (WHO, 2005). A new animal study has tested the action of tea against Trypanosoma brucei. Using mice infected with T. brucei, researchers found that all animals (untreated controls, green tea, white tea, and black tea groups) showed the same levels of infection for the first 8 days. However, from day 9 to 13, parasite levels decreased significantly more in tea-treated animals. By day 11, all teas also showed significant protection against red blood cell destruction. All teas showed significant protection against inflammation by reducing parasite-induced hypoalbuminemia. Both green tea and white tea were superior to black tea. However, black tea was significantly protective, and by some criteria, approached the protective levels of green tea. In addition, all teas were more protective than an established anti-inflammatory drug called dexamethasone (Karori SM, Different types of tea products attenuate inflammation induced in Trypanosoma brucei infected mice, Parasitology International, February 2008). This is a preliminary study, and more research is needed to know if there would be similar results with T. brucei-infected humans. For more research on green tea and infections, see Tea News: Green Tea Protects Brain During Sleep Apnea Sleep apnea is a breathing disorder. During sleep, people with this condition will stop breathing for short intervals up to 30 times an hour. There are many causes for this condition, but the results are similar: oxygen deprivation and less sleep. Oxygen deprivation affects the brain and heart rapidly. Less sleep can lead to daytime fatigue and increased risk of accidents. Sleep apnea is also associated with increased risk of diabetes and obesity (U. S. National Heart Lung and Blood Institute, 2008). In a preliminary study, researchers tested green tea polyphenol (GTP) antioxidants in an oxygen-deprived model that shows the same effects on the brain as sleep apnea in people. Test animals were intermittently deprived of oxygen during their night cycle. One group received water with green tea polyphenol antioxidants and the control group received water only. After two weeks of oxygen deprivation, all animals were tested for learning, oxidative stress, and inflammation. Those receiving water only showed learning loss in a maze test, as well as markedly increased oxidative stress and inflammation. Those receiving green tea polyphenol antioxidants in their water showed that green tea prevented learning loss in the maze test, and reduced both oxidative stress and inflammation, up to 40% in some cases (Burckhardt IC, Green tea catechin polyphenols attenuate behavioral and oxidative responses to intermittent hypoxia, American Journal of Respiratory and Critical Care Medicine, May 2008). Researchers suggested that green tea polyphenol antioxidants may be a useful protective strategy for oxygen deprivation during sleep apnea. Tea News: Green Tea Catechins And Belly Fat Catechins from green tea are polyphenol antioxidants that include the powerful EGCG. While green tea has been shown to improve blood fats like cholesterol levels, a new study examines how green tea catechins can improve other cardiovascular risk factors including belly fat. The study took place during a 12-week multicenter trial with 240 Japanese women and men who had abdominal obesity or belly fat. The subjects were given green tea with high catechins (583 mg.) or low catechins (96 mg.) daily under double-blind conditions where neither the doctor nor the subject knew which tea they received. Compared to the low catechin group, the high catechin group lost more body weight, body fat mass, subcutaneous fat, and belly fat. They lost more distance around their waist and hips. They lowered their body mass index (BMI) more. Their blood pressure dropped more among those who started with systolic blood pressure higher than 130 mm Hg. Their LDL or bad cholesterol decreased more. There were no side effects for either group (Nagao T, A green tea extract high in catechins reduces body fat and cardiovascular risks in humans. Obesity-Silver Spring, June 2007). Controlled potency high catechin EGCG green tea extract is available here: If you are making your green tea from whole leaf tea, you should know that catechins like EGCG are extracted into the hot water at the same time as caffeine. Here's more help preparing a higher catechin/caffeine green tea. Tea News: Green Tea And Hepatitis B A new preliminary study found that green tea extract could effectively inhibit hepatitis B virus (HBV) in the laboratory. Using a stabilized HBV cell line, researchers tested green tea extract and EGCG and the expression of viral antigens, extracellular HBV DNA, HBV mRNA, and other replicative intermediates. In this test, whole green tea extract was more powerful than isolated EGCG (Xu J, Green tea extract and its major component epigallocatechin gallate inhibits hepatitis B virus in vitro, Antiviral Research, June 2008). Hepatitis B is a major health problem worldwide. It is transmitted through blood, sexual contacts, needles, and childbirth. It may be asymptomatic, or cause liver failure and death. Vaccines are the best protection against hepatitis B and are used routinely up to age 18, and in high risk groups or travelers (Center for Disease Control). Tea News: Tea Vs Anthrax? One of the events after the 9-11 World Trade Center attack in the United States was anthrax spores sent through the mail to members of Congress and the press. Anthrax is an infectious disease caused by Bacillus anthracis. Contagion occurs when anthrax spores are inhaled and it can be lethal, as it was for five people in the 9-11 anthrax event. Normally anthrax infection occurs from spores on infected cattle or deer, especially their hides, and has become rare in most areas. But if you are preparing a general emergency kit and want to make it more complete, you might consider adding tea. A new study has found that English Breakfast black tea could kill anthrax more effectively than American coffee. The polyphenols in the tea were able to considerably inhibit the activity of anthrax. However, adding milk, as is the custom for many black tea drinkers, completely stopped any antibacterial action of black tea (Baille L, Microbiology, March 2008). An earlier study found that EGCG from green tea inhibited the lethal metalloproteolytic activity of anthrax so well that it prevented the death of macrophage cells and animals (Dell'Aica I, Potent inhibitors of anthrax lethal factor from green tea, EMBO Reports, April 2004). These studies are considered preliminary. Tea has shown remarkable protective activity against infectious diseases including among others. Tea News: New Immune System Tea Chemical Discovered Research shows that green tea helps the immune system protect the body by fighting bacterial and viral infections. Green tea accomplishes this in ways that are now described as broad-spectrum. Many of the beneficial results have been associated with the chemicals in green tea called catechins, a group of polyphenol antioxidants which includes EGCG (epigallocatechin gallate). Now a new preliminary study has discovered that green tea polysaccharides also help the immune system. Researchers found that green tea polysaccharides extracted from young tea leaves stimulated immune cells called macrophages. Macrophages are white blood cells that engulf and devour bacteria, protozoa, and even cancerous cells. The study found that green tea polysaccharides from younger tea leaves were the most effective. Older tea leaves were not as effective (Monobe M, Immunostimulating Activity of a Crude Polysaccharide Derived from Green Tea (Camellia sinensis) Extract, Journal of Agriculture and Food Chemistry, February, 2008). For green teas that use younger leaves, try Tea News: Green Tea Extract Protects Fat Liver Damage The cost of obesity to an individual's health includes potential additional damage to their physiological systems, structures, and organs like the liver. Nonalcoholic fatty liver disease has increased with increasing obesity. A new study tested green tea extract (GTE) with obese mice and lean mice. After six weeks of green tea extract, the body weights of the obese mice were 23-25% lower and the body weights of the lean mice were 11-20% lower than control mice not fed green tea extract. Fat in the liver was reduced by green tea extract in a dose dependent manner. Green tea helped protect against liver injury probably by reducing serum alanine aminotransferase activity by 30-41% and reducing aspartate aminotransferase activity by 22-33%. Vitamin E, Vitamin C, and adiponectin-mediated fat metabolism were not significantly affected (Bruno RS, Journal of Nutrition, 2008). Researchers concluded that green tea extract protected the liver from obesity by limiting the accumulation of lipids in the liver. Green tea is known to block the absorption of fatty lipids in the intestine, thus increasing the direct elimination of fat before it is absorbed. These studies are considered preliminary. Additional research is needed to determine all the biochemical pathways involved in green tea's protection against liver damage from obesity. Are you worried about obesity? You can learn more here about the importance of counting calories for anti-aging benefits, and maintaining a healthy weight for life. Tea News: Green Tea Chemicals For Colds A recent double-blind study on cold and flu symptoms tested green tea chemicals against placebo with 120 adults (age 18 to 70) for three months. Compared to placebo, the green tea group had significant results showing
The formula for the tested green tea chemicals (decaffeinated 45% EGCG plus theanine) is proprietary and patent-pending, but researchers stated that drinking 10 cups of green tea daily would give an equivalent result (Rowe CA, Journal American College Nutrition, 2007). If you have a health condition that prohibits you from drinking that much green tea, you might want to check the results with a green tea gargle for flu prevention. Tea News: Improving protection against E. coli and Listeria Industrialized societies are always looking for better ways to protect food from contamination, but would you have suspected adding jasmine tea and wildflower honey would help? Researchers have now found that either jasmine or green tea mixed with honey and sprayed on meat products will reduce both Listeria by up to 20% and E. coli 0157 on turkey breast slices and hot dogs. And when the hot dogs had already been pretreated with sodium lactate, potassium lactate, and sodium diacetate, there was a synergistic effect with the tea and honey spray that kept bacterial contamination lower even 14 days later (Fung D, Food Safety Consortium, 2007). These studies are preliminary and need further review before widespread implementation. But the benefits from improved food protection techniques could be great. E. coli contamination has caused approximately 73,000 illnesses annually and cost over $400 million for health care, not including the economic cost of product recalls. Listeria accounts for the majority of deaths annually from contaminated food in the U. S. (CDC). Here's more on food poisoning protection. Tea News: Lemon Or Milk In Your Tea? A preliminary laboratory study has shown that combining green tea with citrus juices like orange, grapefruit, lime, or lemon increases the stability of precious antioxidant catechins like EGCG up to five times greater than plain green tea. Even the addition of cow's milk, soy, or rice milk showed an increase in catechin stability (Green RJ, Molecular Nutrition and Food Research, 2007). But previous researchers on the stability and bioavailability of green tea catechins have checked whether the catechins are stable not only in the laboratory, but also if they show up in the blood stream of human volunteers after drinking. That research has created the controversy over milk in tea. Some blood tests from human volunteers show less catechins after drinking tea with milk and some show the same as plain tea. Adding a little citrus has not been controversial. So, if you're buying bottled green tea mixed with some citrus juice, you might have a better chance of getting some of green tea's catechins. Or not. Other factors like shelf life, sugars, and other additives were not tested here. In any case, the vast majority of research into green tea health benefits has intelligently been based on creating a model comparable to standard human usage called "cup of tea strength." And that body of research shows most of green tea benefits become statistically visible when humans drink around five cups of green tea daily. So, if it's appropriate for your particular health condition, enjoy a cup of freshly made plain green tea. And try it plain. Like fine wine, a premier green tea should be enjoyed for itself. Tea News: New Sources Of Organically Grown Tea From China While increased pollution and industrialized lifestyles are affecting the health of some provinces of China, other provinces are dedicating large areas to organic tea plantations. Far from Shanxi coal mining, Guizhou province has the desired warm, damp climate for tea production. A local history of low industrialization combined with agricultural poverty preventing the use of chemical pesticides or fertilizers have created a unique opportunity in China for organic cultivation. Already, over 18 square miles of tea gardens have passed verification for non-pollution tea and nine square miles have been verified as organically grown. By 2020, this green tea belt in Guizhou could cover up to 334 square miles. Favorite Guizhou tea include Meitan green sprouts, Meijiang green leaf, Yaolao silver sprouts, Zunyi Mao Feng, and Fenggang organic green tea. Thank goodness for organically grown! Tea News: Good News For Decaf Lovers Do you look for decaffeinated green tea, but worry about losing those wonderful antioxidant catechins? Now there may be a new decaffeination process that can retain over 80% of the catechins. Researchers examined cosolvent-modified supercritical carbon dioxide, or SC-CO 2 for short, and found specific parameters that allowed the removal of 91.5% of the caffeine while retaining 80.8% of the green tea catechins (Huang KJ, Journal Agriculture Food Chemistry, 2007). This technology will probably undergo more testing before being implemented in decaffeinated tea manufacture, so here's some tips while you're waiting: 21 Tips On How To Change Your Green Tea Caffeine Levels. Tea News: Supplements Vs Gargle? A recent study on cold and flu prevention in healthy adults compared using green tea supplements to placebo for three months. The researchers found that taking two green tea supplements daily was safe and over 32% fewer people became ill (Rowe C, Journal American College Nutrition, 2007). However.... A study in Japan found that gargling with green tea three times daily reduced illness due to flu by 87%. Gargling can diffuse substances through the mucous membranes, protecting the areas of first contact from airborne infections. Taking supplements helps after the infection has begun to multiply inside the body. Tea News: Matcha, Matcha Everywhere Matcha tea is showing up everywhere. Ice cream, sodas, cakes, cookies, candy, chocolate, even sunflower seeds. Matcha tea, a powdered version of the most tender green tea leaves, has grown from a ceremonial drink to everyday tea to the latest food fashion. While everyone will choose their own favorite matcha preparation, science certainly provides evidence about its benefits. Researchers from Colorado, USA, tested matcha tea for catechin polyphenol antioxidants and compared it to other green teas. Using micellar electrokinetic chromatography, they found that matcha tea had 137 times more EGCG than China green tea (Weiss D, Journal Chromatography A., 2003). Complete information about matcha tea here. EGCG, or epigallocatechin gallate, is the most powerful antioxidant in all the preparations of tea: green, oolong, or black. Green tea normally has 5 times more EGCG than black tea. While matcha is made from green tea, the selection of the youngest leaves for matcha, and the unique preparation concentrates the antioxidants even more than regular green tea. Antioxidants are important to defend all body tissues from damage from free radicals (unattached oxygen) that is associated with aging and many diseases, including heart disease and cancers. Tea News: Theanine--Keep Your Cool With Hot Green Tea A recent study in Japan found that theanine from green tea helped human volunteers keep their cool during a stressful experiment. Researchers found that high stress symptoms mediated by the sympathetic nervous system were reduced after theanine was used (Kimura K, Biol Psychol, 2007). Theanine studies with animals have shown that theanine affects serotonin, dopamine, GABA levels, and reduces high blood pressure. Theanine from green tea also preserves brain cells in the hippocampus and striatum which improves memory and learning. Theanine is an amino acid found only in tea, mushrooms, and a few rare plants. Drinking green tea is the richest natural source of theanine available, although you can find it in supplement form. Check here for a list of green teas available worldwide. Tea News: Infection--Green Tea Attacks Bird Flu They've finally tested green tea against one of the bird flu viruses. Researchers in South Korea synthesized several derivatives of EGC, one of its primary catechin polyphenols. All derivatives worked against the H9N2 avian bird flu virus, as well as human influenza A and B viruses. The derivatives prevented all the flu viruses from attacking red blood cells. Also they were effective in preventing viral growth in amounts far smaller than anti-viral drugs. Here's more information on flu prevention. While this study is preliminary, the researchers believe that the broad spectrum performance of green tea catechin derivatives against these influenza and bird flu viruses could be helpful for pandemic management. (Song JM, Antiviral Research, 2007)
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