All About Green Tea And Polyphenolsby Kurt Hurley
-A discovery is said to be an accident meeting a prepared mind, Albert von Szent-Gyorgyi (1893 - 1986)
Or as I like to say... When the student is ready, the teacher shall appear! By the way, have I said how much I passionately enjoy green tea, the personal benefits I have witnessed from green tea and what a fantastic unearthing this 'ancient medicine' is for modern western living?
After a good deal of research, I have found that there isn't any other food or drink in general consumption reported to have the innumerable health benefits that green tea possesses...none!
The Chinese have known about the medicinal benefits of green tea since ancient times, using it to treat everything from headaches and lethargia to depression. And did you know that green tea has been used as a medicine in China for over 4,000 years... When will we westerners learn?
At present, in both Asia and America, scientific research is providing a more than solid substantiation for the health benefits long associated with drinking green tea. For instance, in 1994 the Journal of the National Cancer Institute published the results of an epidemiological study demonstrating that drinking green tea reduced the risk of esophageal cancer in Chinese men and women by nearly sixty percent. Conversely, University of Purdue researchers recently concluded that a compound in green tea inhibits the growth of cancer cells. There is also research indicating that drinking green tea lowers total cholesterol levels, as well as improving the ratio of good (HDL) cholesterol to bad (LDL) cholesterol.
To abridge just a few of the medical conditions in which drinking green tea has proved to be helpful:
impaired immune system function
elevated cholesterol levels
numerous types of infections
muscle wasting diseases
Green tea's 'secret' lies in the fact it is rich in catechin polyphenols, particularly epigallocatechin gallate (EGCG). EGCG is a powerful anti-oxidant: besides inhibiting the growth of cancer cells, it kills cancer cells without harming healthy tissue. It has also been exceedingly effective in lowering LDL cholesterol levels, and inhibiting the abnormal formation of blood clots. The preceding takes on added importance when you consider that thrombosis (the formation of abnormal blood clots) is the foremost cause of heart attacks and stroke. Quite startling, don't you think?
For The Record Books...
Correlates are being drawn between the effects of drinking green tea and the "French Paradox." For years, researchers were mystified by the fact that, despite consuming a diet rich in saturated fat, the French have a lower incidence of heart disease than Americans. The answer was found to lie in red wine, which contains resveratrol, a polyphenol that limits the negative effects of smoking and a fatty diet. In a 1997 study, researchers from the University of Kansas concluded that EGCG is twice as powerful as resveratrol, which may explain why the rate of heart disease among Japanese men is significantly low, even though in excess of seventy-five percent are smokers.
So why don't other Chinese teas have similar earth-shaking health benefits? Green, oolong, and black teas all come from the leaves of the Camellia sinensis plant. What sets green tea apart is the way it is processed.In particular, green tea leaves are steamed, which prevents the EGCG compound from being oxidized. By contrast, black and oolong tea leaves are processed from fermented leaves, which results in the EGCG being transformed into other compounds that are not nearly as effective in preventing and fighting various conditions and diseases.
Some Additional Benefits...
The latest evidence emerging is that green tea can even help dieters attain success more rapidly an efficiently. In November, 1999, the American Journal of Clinical Nutrition published the results of a study at the University of Geneva in Switzerland. Researchers found that men who were given a combination of caffeine and green tea extract burned more calories than those given only caffeine or a placebo.
Incidentally, green tea can even help prevent tooth decay! Just as its bacteria-destroying abilities can help prevent food poisoning, it can also kill the bacterium that causes dental plaque. Meanwhile, skin preparations containing green tea - from deodorants to creams - are starting to appear on the market showing positive effects.
The Potential Unsafe Effects?
As of today, the only adverse side effect reported from drinking green tea is mild insomnia due to the fact that it contains caffeine. On the other hand, green tea contains much less caffeine than coffee and most soda: there are approximately thirty to sixty mg. of caffeine in six - eight ounces of tea, compared to over one-hundred mg. in eight ounces of coffee and can you imagine the huge contrast in caffeine content between green tea and these 'new' high-tech energy drinks that are currently being consumed by the masses with such ravenous voracity.
Green Tea Polyphenols, What Are They You Ask?
Specifically, tea polyphenols are compounds in tea leaves that are natural plant antioxidants. Antioxidants have been proven to prevent damage caused by free radicals to DNA and other molecules.
How Do They Work?
Green tea polyphenols have corroborated several cancer preventive properties. In addition to antioxidant activity, these compounds may as previously mentioned have shown to reduce abnormal cell growth and inflammation; help the body get rid of cancer-causing agents; and restore communication between different cells in the body.
On Cancer... The Facts
The relationship between green tea consumption and human cancer has been studied in several different populations and at various cancer sites. Some of the studies comparing green tea drinkers to non-green tea drinkers support the claim that green tea-drinking, in fact prevents certain types of cancer. Certain dietary, environmental, and population differences may account for these discrepancies. In animal studies, different tea extracts, tea polyphenol mixtures, purified tea components, and tea infusions as the sole drinking fluid have more consistently been shown to prevent cancer, including cancers of the colon, esophagus, liver, stomach, lung, breast, pancreas, and skin. The purified component, epigallocatechin gallate (EGCG), prevented colon cancer, but did not prevent cancer of the esophagus in animal models. A polyphenol mixture with EGCG, called Polyphenon E, has also shown cancer preventive properties in animals. Animal studies were inconclusive as to whether EGCG or Polyphenol E caused DNA mutations that might trigger cancer growth. Both EGCG and Polyphenon E are being tested for safety and efficacy in humans.
Slower Prostate Cancer Cell Growth Found From Consumption Of Green And Black Tea
A study at The Experimental Biology 2004, in Washington, D.C., reported as part of the scientific program of the American Society of Nutritional Sciences, anti-tumor effects of green and black tea polyphenols in human tissue. And researchers at the University of California at Los Angeles found and were able to detect tea polyphenols in prostate tissue after a very limited consumption of the tea. More notably, the scientists found that prostate cancer cells grew more slowly when placed in a medium containing blood serum of men who had consumed either green or black tea for five days compared to serum collected before the men began their tea-drinking regimen. Serum from men who drank comparable amounts of diet or regular soda showed no such slowing in cancer cell proliferation.
Consequently, Dr. Susanne Henning, UCLA Center for Human Nutrition, pronounced that the UCLA research team - a combination of nutrition scientists and urologists - focused on the feasible outcome of tea polyphenols on factors named polyamines and the enzymes responsible for the production of polyamines. Elevated levels of polyamines have been connected with malignancy in humans, including prostate cancer, and - since polyamines are current in prostate tissue in high concentration - are considered a logical target for chemoprevention of prostate cancer.
Prostate cancer is one of the most widespread cancers among males in the United States, and more than a fourth of all those patients with prostate cancer are known to use alternative therapies, including green tea. This study suggests that both black and green tea are promising natural dietary supplements useful for chemoprevention of prostate cancer, according to Dr. Henning. She plans to investigate if this effect can be enhanced by consuming larger amounts of tea polyphenols in the form of green tea extract supplement capsules.
So If It's That Good, How Much Should I Drink?
Strangely enough, there are as many answers to this question as there are researchers investigating the beneficial properties of green tea and polyphenols. Herbs for Health magazine mentions a Japanese report citing that men who drank ten cups of green tea per day stayed cancer-free for three years longer than men who drank less than three cups a day (there are approximately 240 - 320 mg of polyphenols in three cups of green tea).
Meanwhile, a study by Cleveland's Western Reserve University concluded that drinking four or more cups of green tea per day could help prevent rheumatoid arthritis, or reduce symptoms in individuals already suffering from the disease. And Japanese scientists at the Saitama Cancer Research Institute have discovered that there were fewer recurrences of breast cancer, and the disease spread less quickly, in women with a history of drinking five cups or more of green tea daily.
A University of California study on the cancer-preventative qualities of green tea concluded that you could probably attain the desired level of polyphenols by drinking merely two cups per day. So which is it? I personally don't buy the hype that those that manufacture and sell green tea products are propagating...moderation is, like with all things probably your best bet! But given all the evidence, it is almost certainly safe to plan on drinking four to five cups of green tea daily. If you're a real aficionado, by all means imbibe more; but whether or not you'll derive added health benefits remains to be determined.
Okay, enough science... Let's all just relax and have a cup of green tea or if you like your beverages cold like I do, a glass of 'iced' green tea.
About the Author
Kurt Lee Hurley, operator of www.kreatefitness.com, whose clients refer to him as the "Secret Weapon" has built over 3,000 weight loss success testimonials and his Provo, Utah Wellness Facility, Synergy Fitness Systems has become known as a "Results Factory" a "Living Laboratory" of Achievement, Enhanced Human Performance and a place to congregate for Empowerment and of course, the Success of attaining Weight Loss RESULTS!