Research Studies on Green Tea

Asian People have been drinking Green Tea for centuries – mostly for medicinal purposes. Green tea was actually brought to Japan by the man who started ‘Zen Buddhism’ in Japan over 800 years ago.

This monk visited and studied in China, and brought the tea plant back to Japan because he was certain that the Chinese people were healthier due to their habit of drinking green tea. Since then, the Japanese have brought the growing and processing of green tea to the highest level known in the world.

Even though millions of people swear by the health benefits offered by green tea there are many who wish to know what science has to say about the subject. This page offers a brief but compelling overview of what scientists have discovered.  

Weight Loss & Higher Metabolism:

Who: American Journal of Clinical Nutrition
When: January, 2005 edition
What: Concluded that ‘Catechins’ (a Flavonoid antioxidant which makes up about 25% of a fresh tea leaf) might be useful in the prevention and improvement of life-style related diseases –mainly obesity.

Who: American Journal of Clinical Nutrition
What: Reported a significant increase in energy expenditure (a measure of metabolism), plus also had a significant effect on fat oxidation – a 35-43% increase of daytime thermo genesis the body’s own rate of burning calories)
Also: Green tea was a better choice for weight loss because it did not over stimulate the adrenal glands.

Who: University of Birmingham and the University of Geneva
What: Clinical trials indicate that green tea raises metabolic rates, speeds up fat oxidation and improves insulin sensitivity and glucose tolerance.
It was also noted that it can increase endurance in exercise by improving fat metabolism

Cancers:

Who: New Scientist magazine
What: Article states that numerous studies suggest that green tea protects against a range of cancers, including lung, prostate and breast cancer. The key reason according to
Hirofumi Tachibana’s team at Kyushu University is EGCG (the antioxidant epigallocatechin gallate found in abundant quanitities in green tea).

Who: Journal of the National Cancer Institute
When: 1994
What:  published the results of an epidemiological study indicating that drinking green tea reduced the risk of esophageal cancer in Chinese men and women by nearly sixty percent.

University of Purdue researchers recently concluded that a compound in green tea inhibits the growth of cancer cells.

Breast Cancer
Who: University of Mississippi
When: April 2008
What: Green Tea Ingredient, EGCG, Significantly Inhibits Breast Cancer Growth In Female Mice

Strokes:

Who: University of California, Los Angeles (UCLA)
Where: International Stroke Conference
When: Feburary 2009
What: That drinking three or more cups of tea per day can reduce the risk of suffering a stroke by as much as 21 per cent.

Arthritis:

Who: American Journal of Clinical Nutrition
When: January 2005
What: With collagen-induced arthritis in mice (which is similar to rheumatoid arthritis in humans) the mice given the green tea polyphenols were significantly less likely to develop arthritis.

Who: Case Western Reserve University School of Medicine
When: April 2005
What: A study which showed mice given the green tea polyphenols were significantly less likely to develop arthritis. Researchers also noted that the mice that did still get arthritis even though they were given the green tea polyphenols – developed less severe forms of arthritis.

Heart Disease:

Who: Yale University School of Medicine
Where: Journal of the American College of Surgeons.
When: May 2006
What: Looked at more than 100 studies on the health benefits of green tea. They discussed what they called an “Asian paradox,” referring to lower rates of heart disease and cancer in Asia despite high rates of cigarette smoking. They poeticized believe that the 1.2 liters of green tea that is consumed by many Asians each day provides high levels of polyphenols and other antioxidants. The compounds may work in multiple ways to enhance health of the cardiovascular system. Green tea may also prevent oxidation of the LDL cholesterol (”bad” cholesterol), which, then can reduce the buildup of plaque in arteries.

Immune System:

Who: Brigham and Women’s Hospital
When: April 2003
What: Provided research which indicated that theanine may help the body’s immune system response when fighting infection, by boosting the disease-fighting capacity of gamma delta T cells.

Cognitive Impairment & Alzheimers:

Who: Japanese Study
What: Indicated that elderly Japanese people who drink more that 2 cups a day had a 50 percent lower chance of having any cognitive impairment, in comparison to those who drank only 1 cup of green tea or less per day. Suspected reason: EGCG

Inflammation:

Who: Cellular and Molecular Life Sciences
When: August, 2003
What: That ECGC was useful in prevention or treatment of inflammatory processes
(Note: Inflammation in general is considered by many to be perhaps the leading cause of most all diseases)

Stress (Physical & Mental):

Who: Biological Psychology magazine
When: August 2006
What: L-Thiamine (an amino acid found in green tea) could cause anti-stress effects via the inhibition of cortical neuron excitation.

Gum Disese:

Who: Journal of Periodontology – Reuters Health
When: March 2009
What: Researchers indicated that among middle-aged men, the chances of having gum disease declined as the men’s intake of green tea increased.
For each cup they consumed daily, the risk of having gum disease  (including receding gums) moved lower.

Halitosis – Bad Breath:

Who:  University of Illinois at Chicago
What: Researchers concluded that polyphenols in green tea help inhibit the growth of bacteria that cause halitosis (bad breath).

Anogenital Warts:

Sinecatechin (found in green tea) was shown to be effective in treatment. In a double-blinded, randomized controlled trial with more than 500 patients. 57% experienced a complete resolution of their warts, compared to 34% in the control group. 78% of the patients in the treatment group experienced at least 50% improvement in their warts

Resveratrol VS. EGCG:

Who: University of Kansas
When: 1997
What: Kansas determined that EGCG is twice as powerful as Resveratrol, which may explain why the rate of heart disease among Japanese men is quite low, even though approximately seventy-five percent are smokers.

When NOT to Drink Green Tea:

Patients using the drug Velcade. Patients undergoing cancer therapy with Velcade need to avoid green tea, and especially concentrated products that are available from health food stores according to Mr.Schönthal. (Note: Apparently the green tea stops the drug from doing it’s intended work.)

People Going in for Surgery: Green tea likely has a anticoagulant effect so it effects a surgey patient’s clotting ability.

Bortezomib: A 2009 study at the University of Southern California using mouse models showed that several of the polyphenolic ingredients of green tea, such as EGCG, can bind with the anticancer drug Bortezomib, significantly reducing its bioavailability and thereby rendering it therapeutically useless.  This chemical reaction between EGCG and bortezomib is highly specific and depends on the presence of a boronic acid functional group in the bortezomib molecule. Dr. Schönthal, who headed the study, suggests that consumption of green tea, concentrated green tea extract, and other green tea products (such as EGCG capsules) be strongly contraindicated for patients undergoing bortezomib treatment.

One California study suggested pregnant woman avoid green tea.  NOTE: The preceeeding information was seen at only one website and offered zero additional information (name of the study, who did the study, etc). It is my  opinion if  such a study exists it had to do with green tea extract because Asian people have used green tea daily for literally thousands of years – and I’ve seen no reports that pregant women avoided green tea whatsoever .

NOTE: This list is only a small portion of the research done. People need to take full responsibility for their own health and the information they use in making health decisions. This information is no way a substitute for your own Doctors advice. If you are showing symptoms of any of the ailments noted above please consult your doctor.

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