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 Nadine Taylor M.S., R.D.
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Salada has been working with Green Tea Expert Nadine Taylor, M.S., R.D., to provide the best information on Green Tea. Her articles are relevant and informative on a variety of topics, from Green Tea & Obesity to the Flouride content in tea. Click one of the links below to find out how TEA can impact your HEALTH.
About Green Tea
Green Tea & Antioxidants
Green Tea & Stress
Green Tea & Cancer
Green Tea & Health
Green Tea & Winter Health
Nadine Taylor M.S., R.D.
What in the World is an Antioxidant?
Okay, so by now you’ve undoubtedly heard about green tea’s wonderful antioxidant abilities, and how this particular quality helps it fight dangerous diseases like cancer and heart disease. But what is an antioxidant, anyway? And why would anything that’s anti-oxygen be good for you?
Despite their name, antioxidants don’t work against oxygen. They work against a chemical reaction called oxidation, the same process that turns bananas black, rusts metal and makes oil rancid. Oxidation is the interaction between oxygen molecules and the substances they come in contact with. When that substance happens to be living tissue, damage and disease can occur.
Oxidative damage, the harm caused by oxidation, is primarily caused by free radicals, highly reactive, unstable molecules that travel around the body wreaking havoc. Although free radicals can be generated by exposure to UV rays, toxins, cigarette smoke, microbes and other sources, the most common source is the oxygen molecule itself.
Oxygen typically travels throughout the body in pairs, and these two molecules share electrons. But sometimes this double molecule splits into two separate oxygen molecules called singlet oxygen. When this happens, there are no longer enough electrons to go around, so each oxygen molecule ends up one electron short. This destabilizes the molecule, in a sense throwing it off balance. In order too stabilize itself, it races off throughout the body in search of another electron.
But singlet oxygen doesn’t just wait for a spare electron to float on by. Instead, it boldly steals one from some other molecule. This destabilizes the "new" molecule which, in turn, careens off to steal an electron from yet another molecule. The process ofserial "electron stealing" damages cells, tissues, organs and even entire body systems, and is believed to be a major cause of cancer, heart disease, aging and many other conditions.
Antioxidants work against "electron stealing" by neutralizing and stabilizing free radicals. They do this by donating an electron so that singlet oxygen and other free radicals no longer have the urge to "steal." And while the body does produce a certain amount of antioxidants for the express purpose of taking care of such problems, it also needs the added help of antioxidants found in foods. Among others, these include beta-carotene, vitamins C and E, the mineral selenium, and various phytochemicals such as lycopene and quercetin. But the catechins, especially EGCg, are among the most powerful and effective antioxidants of all.
The Power of the Catechins
For thousands of years the Chinese have known that drinking tea is good for your physical and mental health. But almost nobody in the Western world thought twice about the tea/health connection until the 1970’s. That’s when researchers first noticed a much lower rate of cancer deaths among people living in Japan’s Shizuoka Prefecture compared to people living in other areas of Japan.
When they looked at the lifestyle and habits of the two groups, the researchers could only find one major difference:those living in the Shizuoka Prefecture drank a lot more green tea. The reason they were such big tea drinkers? The Shizuoka Prefecture is Japan’s premier tea-growing region and, with acres of tea springing up practically right outside everybody’s door, those who lived there sipped green tea almost continually throughout the day. Many even refreshed the teapot every so often with a few fresh tea leaves plucked from a nearby bush.
But what was it about green tea that seemed to be protective against cancer? After much study, the researchers came up with the answer: the catechins.
The catechins (pronounced CAT-i-kins) are naturally-occurring plant chemicals found primarily in green tea leaves that have powerful antioxidant and disease-fighting properties. You can find some catechins in a few other foods (such as black tea, ginkgo biloba leaves, dark chocolate and wine), but green tea contains the lion’s share.
There are five types of catechins, with hard-to-pronounce names like gallocatechin, epicatechin, and epigallocatechin. The one that has the most potent health benefits is epigallocatechin gallate, or EGCg for short. The catechins are part of a larger group called the flavonoids which, in turn, are part of an even larger group called the polyphenols. That’s why you’ll sometimes hear the catechins referred to as "tea flavonoids" or "tea polyphenols."
Since scientists first isolated these substances in the 1970’s, the catechins (especially EGCg) have been the subject of thousands of scientific studies. They are best known for their powerful antioxidant action, which reduces the free radical damage that is linked to cancer, cardiovascular disease and other degenerative diseases.
But the catechins can also work other "wonders." To name a few: they can destroy certain powerful bacteria (including salmonella and cholera), inhibit the action of viruses (such as flu virus and HIV), assist in weight loss, fight tooth decay and stimulate the immune system. Clearly the catechins are potent health-protectors! And they are only found in significant quantities in green tea.
The information below is not written by Nadine Taylor.
White Tea
It has been found that in past studies using bacteria, white teas were more effective than green tea in inhibiting mutagenicity, ("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 even found in higher concentrations in white tea than in green tea brewed under the same conditions. Caffeine was also present in higher levels in white tea than in green tea. Source: The Linus Pauling Institute - Oregon State University, March 2003.
Green Tea
Continuing research on the beneficial properties of green tea to human health has produced several new findings. Most notable is a study by Japanese scientists of the Saitama Cancer Research Institute relating the delay of cancer onset with the consumption of green tea. The study shows that early stage breast cancer spreads less rapidly in women with a history of drinking five or more cups of green tea a day. As a result, there is a lower recurrence rate and a longer disease-free period.
With the evidence that green tea and EGCG, a catechin found only in green tea, are a natural and readily available inhibitor of TNF-, a gene expression which promotes the growth in cancer cells and in their surrounding tissue, it is possible for researchers to extend this idea to other various human diseases. Since EGCG has also been proven to kill cultured cancer cells without causing harm to surrounding healthy cells, green tea could be beneficial not only for cancer prevention but also in the therapy and prevention of other diseases.