White tea more effective than green tea in killing germs! |
New studies conducted at Pace University have indicated that
White Tea Extract (WTE) may have prophylactic applications in retarding growth of bacteria that cause Staphylococcus infections, Streptococcus infections, pneumonia and dental caries. The effect of WTE was determined by observing zones of inhibition of bacteria grown on Mueller Hinton II Agar (Kirby-Bauer technique).
White tea was more effective than green tea at inactivating bacterial viruses. Results obtained with the bacterial virus, a model system; suggest that WTE may have an anti-viral effect on human pathogenic viruses. The addition of White Tea Extract to various toothpastes enhanced the anti-microbial effect of these oral agents.
Studies have also indicated that WTE has an anti-fungal effect on Penicillium chrysogenum and Saccharomyces cerevisiae. In the presence of WTE, Penicillium spores and Saccharomyces cerevisiae yeast cells were totally inactivated. It is suggested that WTE may have an anti-fungal effect on pathogenic fungi.
"Past studies have shown that green tea stimulates the immune system to fight disease," says Milton Schiffenbauer, Ph.D., a microbiologist and professor in the Department of Biology at Pace University’s Dyson College of Arts & Sciences and primary author of the research. "Our research shows White Tea Extract can actually destroy in vitro the organisms that cause disease. Study after study with tea extract proves that it has many healing properties. This is not an old wives tale, it’s a fact."
Several findings in the new study are of particular interest:
The anti-viral and anti-bacterial effect of white tea (Stash and Templar brands) is greater than that of green tea.
The anti-viral and anti-bacterial effect of several toothpastes including Aim, Aquafresh, Colgate, Crest and Orajel was enhanced by the addition of white tea extract.
White tea extract exhibited an anti-fungal effect on both Penicillium chrysogenum and Saccharomyces cerevisiae.
White tea extract may have application in the inactivation of pathogenic human microbes, i.e., bacteria, viruses, and fungi.
Milton Schiffenbauer
Pace University
New York, NY, United States
Website: www.pace.edu
Is White Tea Better than other teas as a Potential Anticarcinogen? |
"
White tea" does not refer to black tea with milk, but rather to a specific form of tea in which the leaves and buds are simply steamed and dried. In this sense, white tea represents the least processed form of tea, since green, oolong and black teas undergo withering before various degrees of oxidation. White tea also contains a higher proportion of buds, which are covered with fine 'silvery' hairs that impart a light white/grey color to the tea. White tea brews to a pale yellow/light red color, and has a slightly sweet flavor with no 'grassy' undertones sometimes associated with green tea.
Researchers at the LPI tested four types of white tea for their ability to inhibit mutations in bacteria, and subsequently examined the protective properties in a rat colon cancer model. In the former studies using bacteria, white teas were generally more effective than green tea in inhibiting mutagenicity (mutagenicity is a result of unrepaired/misrepaired DNA damage and an early step in the process leading to cancer). White teas contained many of the expected polyphenols, some of which were present at higher concentrations than in green tea brewed under the same conditions. Other constituents, such as caffeine, also were present at higher levels in white tea.
Rats were given white tea (tea was brewed for 5 min, using 2g/100ml hot water) in the drinking water for up to 8 weeks. A second group was given the equivalent amount of caffeine alone. In weeks 3 and 4, animals were given a carcinogen from cooked meat ("PhIP"). After 2 weeks of treatment, and prior to PhIP dosing, enzyme changes were detected in the liver, white tea being slightly more effective in this regard than caffeine alone. Overall, the altered enzyme profiles, and profiles of metabolites excreted in the urine, suggested that the carcinogen was more rapidly metabolized and detoxified. At the end of the study, rats given white tea had significantly fewer PhIP-induced pre-cancerous lesions in the colon (called aberrant crypt foci, or ACF). However, rats given caffeine alone also had fewer ACF.
These data are highly preliminary, and cannot be extrapolated to human cancer prevention or treatment. They indicate that white tea, like other forms of tea, can block the DNA damage caused by some compounds using a test tube assay with bacteria as indicator organisms. The animal studies scored pre-cancerous changes in the colon, not actual tumors, and raised the possibility that any potential extra 'benefit' from white tea (versus other teas) might simply be related to higher caffeine levels. Finally, animal studies in which inhibition of colon tumor formation has been demonstrated cannot be simply extrapolated to protection in people. LPI researchers are now planning further studies with white tea in animal models (rats, mice, trout), and in a pilot human trial.
The Linus Pauling Institute, Oregon State University.
Website:
lpi.oregonstate.edu
