White Tea : Health Effects - Both White tea popularity and research are still in its early stages although its been produced for over one thousand years (first in China).
White teas are made from buds and young leaves picked shortly before the buds have fully opened, which are steamed or fired to inactivate polyphenol oxidase, and then dried. Thus, white tea retains the high concentrations of catechins present in fresh tea leaves. The tea takes its name from the silver fuzz that still covers the buds, which turns white when the tea is dried. The exact proportion of buds to leaves varies depending on the variety of white tea. For example, White Peony contains one bud for every two leaves, while Silver Needles, the crème de la crème of white teas, is made entirely from downy buds picked within a two day period in early Spring. Green tea is made from more mature tea leaves than white tea, and may be withered prior to steaming or firing. Although they are also rich in catechins, green teas may have different catechin profiles than white teas. Tea leaves destined to be sold as white tea undergo even less processing than green tea leaves. Instead of air-drying, the unwithered leaves are merely steamed. The result? A pale tea with a sweet, silky flavor. People who have tried both note that white tea lacks the “grassy” aftertaste so often associated with green tea. Leaving tea leaves so close to their natural state means that white tea contains more polyphenols, the powerful anti-oxidant that fights and kills cancer-causing cells, than any other type of tea.
REFERENCE: Santana-Rios G, Orner GA, Amantana A, Provost C, Wu SY, Dashwood RH. Potent antimutagenic activity of white tea in comparison with green tea in the Salmonella assay. Mutat Res. 2001;495(1-2):61-74.
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.
REFERENCE: Dr. Schiffenbauer, Pace University, 104th General Meeting of the American Society for Microbiology on May 23, New Orleans, Louisiana
"Similar to the way oxidation causes a car to rust, oxidative stress of the skin causes a breakdown in cellular strength and function. The white tea extract protects against this stress. This study further demonstrates the importance of researching how plant products can actually protect the skin," says Dr. Baron, who worked with Seth Stevens, MD, principal investigator for the study.
As part of the study, scientists applied a white tea extract cream to one patch of skin on the subject's buttock (skin that is not ordinarily exposed to much sunlight), while another area was left unprotected. Both areas were then exposed to artificial sunlight. Researchers then reapplied the white tea extract to the area previously coated. Three days later the scientists compared the patches of skin on a cellular level. Here's what they looked for:
In the immune system, the Langerhans cells in the outer layer of the skin (epidermis) are the outermost reach of the immune system, and are the first to recognize foreign agents. They are the sentinel cells or watchdog cells, essential in detecting germs and mutated proteins produced by cancerous cells; but, because of their location, the Langerhans cells are very sensitive to damage by sunlight.
Scientists in the study found the white tea extract protected against the Langerhans cell obliteration that was observed in the sun-exposed skin not treated with the extract. The investigators then tested whether the preserved immune system cells in the white tea extract-protected skin would still function properly after exposure to sunlight; they discovered the immune function was indeed restored by the extract. They also found that the DNA damage that can occur in cells after exposure to sunlight was limited in the skin cells protected by the white tea extract.
Researchers believe that white tea extract's anti-oxidant properties are the reason the extract was effective; if so, it also suggests that the agent may provide anti-aging benefits. The same process of oxidative stress in skin cells that leads to immune system damage can also promote skin cancer and photo damage, such as wrinkling or mottled pigmentation.
Kevin Cooper, MD, is chairman of the department of dermatology at UHC and CWRU. "We know that younger skin tends to be able to resist the oxidative stress associated with exposure to the destructive rays of sunlight. The white tea extract also appears to build the skin's resistance against stresses that cause the skin to age."
The results offer promise in the battle against skin cancer, the most common form of cancer in the United States with more than one million new cases diagnosed every year, according to the researchers. This study was funded by Origins Natural Resources, a division of The Estee Lauder Companies (ELC).The Skin Study Center at UHC and CWRU has studied the benefits of another form of tea that has protective effects. Researchers found that ingredients in green tea decreased the direct effects of sunburn. This newest study is the first of its kind involving white tea. White and green teas contain the highest amounts of antioxidants of all tea varieties, but white tea is actually the least processed form of tea and is rarely used in consumer products.
REFERENCE: Steves, Seth,Skin Study Center at University Hospitals of Cleveland and Case Western Reserve University, 01-30-03.
A new study from the Linus Pauling Institute at Oregon State University suggests that consumption of green and white tea can be just about as effective as use of the prescription drug sulindac in preventing colon tumors in a certain type of laboratory mouse that is genetically predisposed to cancer. The control group of mice received no treatments, and developed an average of about 30 tumors each. The most effective results were obtained with a combination of tea and sulindac.
It may suggest some optional approaches to cancer prevention or therapy, especially for people who have trouble with the side effects that can be associated with regular use of non-steroidal anti-inflammatory drugs, or NSAIDs, such as sulindac or aspirin.
The study also indicated that routine consumption of green or white teas could be especially effective in combination with NSAIDs, and provide more cancer protection than either of the products separately.
"Tea is one of the most widely consumed beverages in the world, and recent upswings in the sales of green tea in the United States can be attributed to reports of potential health benefits against cancer and other chronic diseases," said Gayle Orner, an OSU research associate, in the report. "Teas exert significant protective effects in experimental animal models of skin, lung, esophageal, gastric, hepatic, small intestinal, pancreatic, colon, bladder and mammary cancer."
OSU's Linus Pauling Institute has been at the forefronts of efforts to examine the effectiveness of white versus green tea in blocking mutagens and preventing cancer. In the latest study, they examined green and white teas that have high levels of the protective polyphenols called catechins, and also compared these teas to sulindac. This drug is commonly used around the world for many purposes, including the prevention of certain colon cancers.
"We have evidence that consumption of tea at the same time as a person ingests mutagens can potentially block some of the effects of the mutagens through changes in metabolism," said Rod Dashwood, a professor in the Linus Pauling Institute. "But since everyone probably has some DNA damage in their cells, another question becomes, is there anything we can do to prevent cancer progression even after cells are damaged?"
To study this, the researchers used as a model a special group of laboratory mice that are genetically predisposed to tumor development, especially in their intestines.
A group of these mice that received no treatment each developed about 30 polyps in their colons. Other research has shown that a therapy with sulindac, the prescription NSAID, could cut polyp formation in these mice about in half.
But consumption of green tea, the scientists found, reduced the number of tumors in the mice from an average of 30 to 17; and consumption of white tea from an average of 30 to 13. Mice given both sulindac and white tea, in combination, saw a tumor reduction of about 80 percent, from 30 tumors to six.
"These are pretty exciting results," Orner said. "What's especially significant is that as far as we can tell consumption of tea has none of the side-effects of NSAIDs, which can be severe, including bleeding, ulcers and even death."
Use of NSAIDs for cancer prevention, heart disease and other concerns is increasingly common with many people, and high aspirin intake has been associated with a 40-50 percent decrease in colon cancer mortality, the researchers note in their report.
Although the complications from prolonged use of NSAIDs can be significant, they often are dose-dependent, the researchers noted in their report. Any cancer preventive agent that worked effectively in combination with NSAIDs and allowed use of lower dosages could be quite significant, the scientists said, and green or white tea consumption may fit that description exactly. Tea and its constituents also have been found to have many additional cancer-preventive mechanisms in their own right, the report said. These include antioxidant properties, induction of cell-cycle arrest, inhibition of oncogene expression, apoptosis induction, and other factors. In-vitro studies, they said, have suggested that tea plus sulindac may work in synergy to kill human lung cancer cells.
Consumption of black tea does not appear to the have the same anti-cancer properties in some situations as green or white tea, the researchers said. White tea, the least processed of all teas, has the highest levels of polyphenols and antioxidants, and is available at specialty tea stores, over the Internet, and in some grocery stories.
Polyphenols can also be purchased as a dietary supplement, the scientists said, but even less is known about how they function in the body, compared to the consumption of food products.
The level of tea consumption in humans that might provide useful levels of polyphenols could be equated to drinking about three coffee-sized mugs a day, the scientists said. This is based on studies in Japan with green tea and gastric cancer, where researchers essentially concluded, "the more the better."Colon cancer is one of the leading causes of cancer death worldwide, and continued advances in its prevention and therapy will require better understanding of these diet and drug interactions, Dashwood said. Ultimately, a diverse regimen of drugs, dietary factors, routine checkups, medical and surgical treatments may all play key roles in preventing death from this cancer, he said.
REFERENCE: Strauth, David, Tea Compliments Drugs in the Fight Against Colon Cancer, Linus Pauling Institute at Oregon State University, in studies funded by the National Cancer Institute, 03-04-03.