by Lynn Hinderliter CN, LDN
Our natural health vocabulary contains a new word: Catechins. This is a type of Polyphenol or plant derived substance, found in green tea, which has shown strong antioxidant and free radical oxygen scavenging properties.
Of course, this is not news to the people of the Orient: in the year 1211 A.D. a Japanese monk wrote ” Tea is a miraculous medicine for the maintenance of health. Tea has an extraordinary power to prolong life. Anywhere a person cultivates tea, long life will follow. In ancient and modern times, tea is the elixir that creates the mountain-dwelling Immortal”. (A reference, I suppose, to the fact that tea grows in the high hills.)
Certainly an interesting study published in the Tohoku Journal of Experimental Medicine in 1992 bolstered this claim: it followed the mortality rates of over 3,000 Japanese women who, as practitioners of a specific tea ceremony, drank more than usual amounts of green tea. The results indicated “the possibility that green tea is a protective factor against premature death”.
Some of the health benefits attributed to Green Tea follow, some supported by studies and some admittedly anecdotal.
I would advise avoiding Green Tea during pregnancy.
Green Tea is called a cancer fighter, (drinking 2 or more cups a day reduced cancer risk by 10% in one group of women studied) and a new study from the University of California suggests that the way Green Tea affects stomach cancer risk is by lowering incidence of gastritis, or inflammation of the stomach lining. In this study of more than 600 Chinese men and women, the researchers found that green tea drinkers were only half as likely as non drinkers to have stomach cancer or gastritis. (International J. of Canc., 2001; 92: 600-604) Green Tea also is beneficial for ulcer healing, and it is postulated that this is because it helps control H. Pylori, the bacterium implicated in many stomach ulcers. This is because one of the active ingredients, EGCG, binds to folic acid, thereby increasing the risk of certain folate related birth defects.
In 2005, the FDA stated it was “highly unlikely” that green tea would prevent cancer . At the same time, another report on the substance in green tea that might fight cancer came out: apparently it affects a ‘promiscuous’ protein that pharmaceutical experts are already targeting in their work on anti-cancer drugs. http://www.medicalnewstoday.com/medicalnews.php?newsid=24496
At the University of Rochester, a study in 2003 concentrated on the relationship between epigallocatechingallate (EGCG), epigallocatechin (EGC), and a harmful molecule called Aryl Hydrocarbon, implicated in the destructive effect tobacco smoke and dioxin have on cells. For the full report, see RESOURCES.
It is also protective against a number of liver problems, notably cirrhosis, and because of the hepatoprotective factor, it is also found to lower cholesterol. Additionally, it protects against the ‘flu virus, has a beneficial effect on blood sugars, helps in the control of high blood pressure, and even fights plaque in the mouth.
In fact, the Georgia Medical College recently (2002) published a study to show that 4 to 6 cups of green tea a day not only prevent the growth of oral cancer cells, but encourage the growth of healthy cells and the demise of existing cancer cells. Even now, it is an ingredient in some mouthwashes, if you don’t enjoy drinking the tea. Or use the a Green Tea liquid extract to swish about in your mouth. Some studies have shown that green tea, and green tea extracts, are more efficient free radical scavengers than Vitamin E and C! This may explain the long list of benefits claimed for it.
Green tea may help you retain the information in this article
A very interesting study published in J. Nutr. 132:341-346, 2002, which built on studies showing Green Tea had anti-inflammatory effects: the researchers wished to find out whether it was also protective of joint tissue. They found that, in vitro at least, the catechins in Green Tea ( and particularly the gallates) appeared to inhibit the breakdown of cartilage as well as reducing inflammation. There were no toxic effectsA Japanese study found that elderly people who drank more than 2 cups of tea a day, benefited cognitively from the intake. http://www.ajcn.org/cgi/content/abstract/83/2/355?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&author1=kuriyama&fulltext=green+tea&searchid=1140468099889_11952&FIRSTINDEX=0&sortspec=relevance&journalcode=ajcn
Does Green Tea contain caffeine?
For those to whom this is still a concern , however, Green Tea extracts are available in capsules, which optimally will contain a 4:1 concentration – the equivalent of 4 cups of green tea! Green Tea is also available in a decaffeinated form. I personally do not see that this should be a concern for most people in view of the information above, but I know that some of us are exceptionally sensitive to caffeine: so I will only say, be sure the caffeine has not been chemically extracted! The chemicals may be worse for you than the caffeine.The answer is that yes, it does – between 4% and 7% of the tea leaf: however, it appears that the high levels of catechins in green tea mean that the caffeine molecule is bound when the tea is steeped, and the effect of the caffeine in green tea is minimized. New research from Tokyo has discovered the presence of an amino acid called L-Theanine which also counteracts the effect of the caffeine, so that one gets the benefit of both stimulation and relaxation from the beverage. Isn’t Nature wonderful?
There is also one particularly pleasant tea extract by Viva called Chi Tea, which not only has no caffeine, not only tastes terrific, but contains extremely high levels of polyphenols! see RESOURCES.
To me, one of the most interesting claims is that green tea reduces the risk of stroke – a Dutch study showed reductions of 73% in the number of strokes in men drinking even black tea, which contains lower rates of catechins! And there is also the suggestion that it may be as effective as aspirin in reducing blood clotting, which is good because it is obviously a much more all round healthy choice than aspirin, which can have dangerous side effects.
What’s out there in the way of choices? There’s your basic green tea, (look for high quality: storage and processing methods affect nutrient levels) & there are now some teas which also have green tea extract added for more potency: there are also the actual capsules of green tea extract, and the concentrated extract mentioned above. It certainly sounds as though this important nutrient is something that should be added in some form or another to one’s diet.
You might want to consider a little soy milk in your green tea, if you read the study below.
Science News, April 29, 2000
Soy-rich diets appear to help fight certain cancers. Tea drinking has been linked to similar benefits. Two studies now find that the combo offers a potent double whammy against cancer of the breast and prostate -at least in mice. Jin-Rong Zhou and his colleagues at Harvard Medical School in Boston injected a million breast cancer or prostate cancer cells into mice engineered to possess weak immune systems. Two weeks earlier, they had replaced the drinking water of some animals with green or black tea. Others received chow laced with isoflavones, soy’s biologically active antioxidants. Two groups of mice got both the mix of isoflavones and one or the other tea. Some just ate their normal diet. Two months after implantation of the cancer cells, the researchers surveyed for tumors and found that all the experimental diets had conferred some benefit. Compared with animals on the normal diet, mice given isoflavones or tea had 25 to 50 percent fewer tumors, and their tumors weighed 15 to 25 percent less. However, benefits from pairing tea and isoflavones equaled or exceeded the sum of either alone–a reduction of between 72 and 87.5 percent in tumor number and a similarly large decrease in each tumor’s size.
Green Tea and its Anti-Ageing properties – http://www.vivaherbals.com/pages/Antiaging_&_Cancer.html
Green Tea and Heart Health – http://www.vivaherbals.com/pages/Cardio.html
Green Tea and Oral Cancer – http://dentistry.about.com/webapps/whereabout/dentistry.about.com/library/weekly/aa070402.htm