Green tea extract has four main functionalities: antioxidant, anticarcinogen, anti-inflammatory and anti-radiation.
Green tea is the beverage brewed from steeping the leaves. The extract is an herbal derivative obtained by various levels of infusion, spraying, drying and forming into tablets, capsules or dry mixes for supplementation.
As an antioxidant, green tea and its extract are hard to beat. Dr. Tariq M. Haggi, an authority on green tea and an associate professor of medicine at Case Western Reserve University claims that the catechin EGCG in green tea has 100 times the antioxidant potency of vitamin C and 25 times more than Vitamin E.
There are numerous abstracts of various medical journal articles listed in Pub Med concerning the antioxidant properties of green tea polyphenols based on animal studies but most conclude with some sort of statement to the effect that more research needs to be done with human subjects.
OK, so let's get on with the studies.
Many of the lab rat experiments indicate that the antioxidant value of green tea extract is best seen in its ability to protect DNA and "macromolecules" from oxidative damage leading to cancer, heart disease and inflammation induced autoimmune conditions.
We don't want to get into the deep science here, just enough to get the message across that green tea extract is a super antioxidant, it works, drink it, you'll like it.
Concerning cancer, Dr. David Servan-Schreiber, MD, PhD, has a lot to say about green tea and cancer in his book, Anti-Cancer: A New Way of Life (2008, Viking Penguin, USA).
He reports that the catechin epigallocatechin gallate (EGCG) in green tea works to block angiogenesis, the process whereby cancer cells signal the body to form new blood vessels to feed the tumor.
He also confirms what others have said regarding the fermentation of tea. Fermentation destroys EGCG thus black tea, which is fermented, is very deficient in EGCG but it is available in large quantities in green tea which is unfermented (that's why it's green).
After just 2 or 3 cups of green tea, EGCG can be detected in the bloodstream and spreads throughout the body via capillaries which feed every cell in the body. EGCG acts to block the cell receptors that allow cancer cells to invade healthy cells. In addition they block the receptors that control angiogenesis.
Servan-Schreiber also comments on the work of a Canadian team in Montreal who tested the effects of EGCG on leukemia, breast, prostate, kidney, skin and mouth cancers and found that it slowed the growth of all of them.
Green tea extract's role in fighting inflammation has been widely reported in several prestigious medical journals.
For example, "Arthritis Today" published by the Arthritis Foundation reported on a study showing that green tea extract was able to "thwart" the inflammatory chemical that plays a role in joint damage from rheumatoid arthritis.
A second study reported in their journal focused on the salivary glands on two groups of people; one that drank only water, the other drank green tea extract.
The latter group experienced a mild-immune system response showing lower levels of white blood cells and autoantibodies indicating an increased level of protection against inflammatory autoimmune conditions.
Specifically, this latter study has significance for sufferers of Sjogren's Syndrome, an autoimmune disease that damages the glands that produce tears and saliva.
The anti-inflammatory effects of EGCG have been known for quite a few years. There is a 2001 study reported in the Journal of Nutrition that demonstrates the ability of EGCG to inhibit inflammatory responses and could lead to treatments in conditions such as inflammatory bowel disease.
This was a study conducted on lab mice and was published and titled, "Green Tea Polyphenal Extract Attenuates Inflammation in Interleukin-2-Deficient Mice, A Model of Autoimmunity".
These are only two out of many published studies on the anti-inflammatory benefits of green tea polyphenols. Another one was published in The Journal of Inflammation on January 5, 2007 and described a rat study in which green tea polyphenols increased anti-inflammatory tristetroprolin (a family of anti-inflammatory proteins) and decreased pro-inflammatory tumor necrosis factor mRNA levels.
As is always the case, the medical community and the researchers will say that mice and rats aren't humans and there is no evidence that the same results will be seen in people.
There is no evidence because the testing on people hasn't been done but that does not negate the positive outcomes of many, many people who have experienced the benefits of using green tea or its extract.
The use of green tea extract in treating skin inflammation and infection from radiation therapy is an interesting example of green tea as an external herbal remedy. Both are painful side effects of radiation and can be so severe as to temporarily halt the treatments.
A study was conducted by Doctors in Germany using 60 patients with radiotherapy skin toxicity from treatment of head, neck and pelvic cancers. The duration of skin toxicity was reduced from an average of 26 days to 16-17 days when treated with green tea extract.
Another telling observation came from Japan following the dropping of atomic bombs on Hiroshima and Nagasaki. Survivors who had been drinking green tea for most of their lives did not suffer as severe radiation effects as those not drinking green tea.
In addition the green tea drinkers recovered sooner and experienced greater longevity with better immune function and greater leukocyte activity. Radiation has the effect of weakening the immune system by damaging bone marrow that produces both white and red blood cells. Green tea extract seems to mitigate the effect.
Might these findings have implications for modern environmental radiation from x-ray machines, cell phones, computers, research labs using radioactive material, nuclear power plant workers, living under high tension transmission lines and similar situations? Time will tell as more research is conducted.
Since not all green tea extract supplements are created equal, it pays to know what to look for. The polyphenol catechin in green tea that is believed to be most effective at mitigating cancer is epigallocatechin, abbreviated EGCG.
In selecting the supplement it is necessary to look for a product that is standardized, meaning that each pill or capsule contains the same amount of EGCG.
As to how much, 55% seems to be the percentage of EGCG to look for which in the usual 500mg capsule serving would be 275mg of EGCG. The total polyphenol content should be around 90% at a minimum. If drinking green tea, two cups a day should do the trick for EGCG intake.
As to brands, most national chain drugstores like Walgreen's or CVS carry brand names like Nature Made or Nature's Bounty, both of which offer a green tea extract. Both a bit light in the EGCG content and not all are labeled as standardized.
Outlets like the Vitamin Shoppe or GNC stores found in almost every major mall in America both carry green tea extract products but the GNC Herbal Plus Standardized Green Tea Complex in 500mg capsules appears to be superior to most drugstore brands or specialty shops.
The best of class in green tea is straight from Japan and is certified organic by the USDA. It is Royal Match Green Tea and is both expensive and often hard to get. The leaf crop is only harvested once a year by hand and most is reserved to internal use in Japan, notably for upscale tea ceremonies.
For all the hoopla, an actual image of the label showing the actual content of EGCG or polyphenols could not be found but that is probably because it is green tea and not the extract.
On Mercola's site, he claims that a serving of Royal Matcha provides 100 times more EGCG than traditional brewed green tea. To check it out on Amazon, click the text link below.
As always, when faced with a catastrophic disease like cancer it is not very smart to try self-medicating with green tea extract, turmeric or anything else.
Treatment, including any type of supplementation, should only be undertaken with the guidance of a qualified medical professional, preferably an oncologist for cancer treatment.