Jon's Health Notes: Green Tea

One of my hobbies is collecting information on research involving personal health matters. I’d like to share some of this with you.

I try to drink at least 2 strong cups of green tea a day, preferably with a little bit of orange juice. Here’s why:

Reader quote: “ Note, though, that green tea is contraindicated with Coumadin, or so my husband's cardiologist says.”

Drinking Tea May Offer Health Benefits

Tea drinkers who opt for black, oolong, green or white teas may find that these beverages offer health benefits. The April issue of Mayo Clinic Health Letter covers what is -- and isn’t -- known about the health effects of drinking tea.
Black, oolong, green or white teas have a common origin. Each is produced from the leaves of the Camellia sinensis bush. The leaves are loaded with flavonoids and other polyphenols that work as antioxidants, possibly lowering the risk of some diseases.
While numerous studies have found possible benefits, the actual benefits of drinking tea are not certain. Most research about tea’s benefits is based on population (epidemiological) studies. Findings are limited because factors other than tea consumption could influence the results. Here’s some of what’s known about tea’s potential benefits:
Cardiovascular: It’s still uncertain if drinking tea over long periods might positively affect cholesterol levels, blood pressure and atherosclerosis. There’s some early evidence that regularly drinking green tea may reduce heart attack risk or atherosclerosis. .
Bone and joint health: Early laboratory research indicates green tea could be beneficial in reducing inflammation related to arthritis and slowing cartilage breakdown. Some early data indicate that regular tea consumption might improve bone mineral density in older women.
Memory: Studies are limited, but a recent one found that older adults in Japan who drank green tea daily showed less risk of memory difficulty, compared with those who didn’t drink tea regularly.
While there’s still much to learn about tea’s health benefits, the potential benefits seem to be in the cup, not in supplements or tea extract capsules. So far, there’s no certainty that the compounds in supplements are the same ones in tea, and even less certainty that these supplements might provide the same potential health benefits as tea.
Green tea boosts production of detox enzymes, rendering cancerous chemicals harmless
Concentrated chemicals derived from green tea dramatically boosted production of a group of key detoxification enzymes in people with low levels of these beneficial proteins, according to researchers at Arizona Cancer Center.
These findings suggest that a green tea concentrate might help some people strengthen their metabolic defense against toxins capable of causing cancer.
“This is the first clinical study to show proof that chemicals in green tea can increase detoxification enzymes in humans,” Chow said. “There may be other mechanism in play by which green tea may protect against cancer development, but this is a good place to start.”
Green Tea May Help Fight Rheumatoid Arthritis

A new study from the University of Michigan Health System suggests that a compound in green tea may provide therapeutic benefits to people with rheumatoid arthritis.

Researchers found that the compound inhibited the production of several molecules in the immune system that contribute to inflammation and joint damage in people with rheumatoid arthritis.

The compound from green tea also was found to suppress the inflammatory products in the connective tissue of people with rheumatoid arthritis._

Green tea may help prevent autoimmune diseases

Green tea may help protect against autoimmune disease, Medical College of Georgia researchers say.__

Approximately 30 percent of elderly Americans suffer from degrees of dry mouth, says Dr. Stephen Hsu, a researcher in the MCG School of Dentistry and lead investigator on the study. Only 5 percent of the elderly in China, where green tea is widely consumed, suffer from the problem.

Researchers already know that one component of green tea – EGCG – helps suppress inflammation, according to Dr. Hsu.__

“So, we suspected that green tea would suppress the inflammatory response of this disease. Those treated with the green tea extract beginning at three weeks, showed significantly less damage to those glands over time.”_

Researchers also suspect that the EGCG in green tea can turn on the body’s defense system against TNF-alpha – a group of proteins and molecules involved in systemic inflammation. TNF-alpha, which is produced by white blood cells, can reach out to target and kill cells. Further study could help determine green tea’s protective role in other autoimmune diseases, including lupus, psoriasis, scleroderma and rheumatoid arthritis, he says.

Green tea may protect from inflamed bladder

Herbal agents could be used to treat inflammatory bladder diseases, according to a preliminary study that looked at the ability of green tea to protect bladder cells from inflammation. The University of Pittsburgh School of Medicine study found that components of green tea protected bladder cells from damage in culture.

Green tea, reported to have many health benefits, is rich in powerful antioxidants that make it a possible remedy for many medical conditions. It is comprised of catechins – plant metabolites that provide it with many anti-oxidative properties.

Green tea may protect brain cells against Parkinson's disease
Does the consumption of green tea, widely touted to have beneficial effects on health, also protect brain cells" Authors of a new study being published in the December 15th issue of Biological Psychiatry share new data that indicates this may be the case. The authors investigated the effects of green tea polyphenols, a group of naturally occurring chemical substances found in plants that have antioxidant properties, in an animal model of Parkinson’s disease.
The authors discovered that green tea polyphenols protect dopamine neurons that increases with the amount consumed. They also show that this protective effect is mediated by inhibition of the ROS-NO pathway, a pathway that may contribute to cell death in Parkinson’s.
Milk eliminates cardiovascular health benefits of tea

Research published in the European Heart Journal has found that the protective effect that tea has on the cardiovascular system is totally wiped out by adding milk.

Tests on volunteers showed that black tea significantly improves the ability of the arteries to relax and expand, but adding milk completely blunts the effect. But, again, adding milk blocked the effect.
Citrus Juice, Vitamin C Give Staying Power to Green Tea Antioxidants
To get more out of your next cup of tea, just add juice.
A study found that citrus juices enable more of green tea's unique antioxidants to remain after simulated digestion, making the pairing even healthier than previously thought.
The study compared the effect of various beverage additives on catechins, naturally occurring antioxidants found in tea. Results suggest that complementing green tea with either citrus juices or vitamin C likely increases the amount of catechins available for the body to absorb.
Catechins (pronounced KA'-teh-kins), display health-promoting qualities and may be responsible for some of green tea's reported health benefits, like reduced risk of cancer, heart attack and stroke. The problem, Ferruzzi said, is that catechins are relatively unstable in non-acidic environments, such as the intestines, and less than 20 percent of the total remains after digestion.
"Off the bat you are eliminating a large majority of the catechins from plain green tea," Ferruzzi said. "We have to address this fact if we want to improve bodily absorption."
Ferruzzi tested juices, creamers and other additives that are either commonly added to fresh-brewed tea or used to make ready-to-drink tea products by putting them through a model simulating gastric and small-intestinal digestion. Citrus juice increased recovered catechin levels by more than five times, the study found. Ascorbic acid, or vitamin C, used to increase shelf life in ready-to-drink products, increased recovered levels of the two most abundant catechins by sixfold and 13-fold, respectively.
Lemons and tea go even better together than their popularity might suggest. Lemon juice caused 80 percent of tea's catechins to remain, the study found. Following lemon, in terms of stabilizing power, were orange, lime and grapefruit juices. Ferruzzi said both vitamin C and citrus juices must interact with catechins to prevent their degradation in the intestines, although data made it clear that citrus juices have stabilizing effects beyond what would be predicted solely based on their vitamin C content.

"If you want more out of your green tea, add some citrus juice to your cup after brewing or pick a ready-to-drink product formulated with ascorbic acid," Ferruzzi said.

Ready-to-drink green tea products should optimally contain 100-200 mg of catechins, but oftentimes do not have sufficient levels of tea extract since some people do not like green tea's flavor, Ferruzzi said.

Although this study only examined green tea, Ferruzzi said he suspects that some of the results also could apply to black tea, which is produced by fermenting green tea. Many prefer black tea's flavor, although it contains lower total levels of catechins.

Green tea helps beat superbugs
Green tea can help beat superbugs according to Egyptian scientists speaking today (Monday 31 March 2008) at the Society for General Microbiology’s 162nd meeting being held this week at the Edinburgh International Conference Centre.
The pharmacy researchers have shown that drinking green tea helps the action of important antibiotics in their fight against resistant superbugs, making them up to three times more effective.
Green tea is a very common beverage in Egypt, and it is quite likely that patients will drink green tea while taking antibiotics. The medical researchers wanted to find out if green tea would interfere with the action of the antibiotics, have no effect, or increase the medicines’ effects.
“We tested green tea in combination with antibiotics against 28 disease causing micro-organisms belonging to two different classes,” says Dr Mervat Kassem from the Faculty of Pharmacy at Alexandria University in Egypt. “In every single case green tea enhanced the bacteria-killing activity of the antibiotics. For example the killing effect of chloramphenicol was 99.99% better when taken with green tea than when taken on its own in some circumstances.”
Green tea also made 20% of drug-resistant bacteria susceptible to one of the cephalosporin antibiotics. These are important antibiotics that new drug resistant strains of bacteria have evolved to resist.
The results surprised the researchers, showing that in almost every case and for all types of antibiotics tested, drinking green tea at the same time as taking the medicines seemed to reduce the bacteria’s drug resistance, even in superbug strains, and increase the action of the antibiotics. In some cases, even a low concentration of green tea was effective.


Green Tea Shown to Possess Antitumor Effect in Breast Cancer
A team of scientists have shown that green tea has antitumor effect in breast cancer cells.
Cancer is a disease caused by the increased proliferation of cells which group and form a lump called tumor. Tumors can be benign or malignant. Cells from malignant tumors break away from the original tumor and spread to other parts of the body growing and forming new tumors. They can invade, penetrate into blood and lymphatic vessels, circulate via the bloodstream and can grow in a normal organ or tissue anywhere in the body. Unfortunately treatment options for metastasis are very limited and usually represent the end stage of the disease.
Unlike malignant tumors, benign tumors do not invade and, with very rare exceptions, are not life threatening. Chemoprevention broadly implies the use of a chemical substance of either natural or synthetic origin, to prevent, hamper, arrest or reverse a disease. Phytochemicals are plant based non nutritive components with substantial medicinal properties.
Dr. Maheshwari’s study observed that green tea can inhibit the invading capacity of these breast cancer cells and have also identified the mechanisms involved in death inducing and invasion inhibiting effects of green tea. Epidemiological studies also suggest that the risk of breast cancer is found to be less in Asian countries consuming green tea. These studies have greater clinical significance since the ability of these phytochemicals to activate anti-cancer program of tumor cells might determine the success of chemotherapy.
Green tea is effective in delaying tumor incidence as well as in reducing the tumor burden. Green tea was found to inhibit growth of tumors as well as induce death of breast cancer cells.

Ingredient Found In Green Tea Significantly Inhibits Breast Cancer Growth In Female Mice
Green tea is high in the antioxidant EGCG (epigallocatechin-3- gallate) which helps prevent the body’s cells from becoming damaged and prematurely aged. Studies have suggested that the combination of green tea and EGCG may also be beneficial by providing protection against certain types of cancers, including breast cancer. A new study conducted by researchers at the University of Mississippi researchers now finds that consuming EGCG significantly inhibits breast tumor growth in female mice. These results bring us one step closer to better understanding the disease and potentially new and naturally occurring therapies.
Epidemiological studies suggest that green tea and its major constituent, EGCG, can provide some protection against cancer. Because these studies were very limited, the anti-cancer mechanism of green tea and EGCG was not clear. As a result, the researchers examined whether drinking EGCG (just the antioxidant infused in water) inhibited the following: expression of VEGF (vascular endothelial growth factor, which is found in a variety of breast cancer types); tumor angiogenesis (thought to help tumors expand by supplying them with nutrients); and the growth of breast cancer in female mice.
Dr. Gu, the senior researcher for the study, hypothesized that the reason for the link between EGCG and the reductions in the cancer data was because EGCG directly targets both tumor blood vessels and tumor cells of breast cancer for suppressing the new blood vessels formation in breast tumor, the proliferation and migration of breast cancer cells.
Gu concluded by saying, “In this study we have demonstrated that the frequent ingestion of EGCG significantly inhibits breast tumor growth, VEGF expression and tumor angiogenesis in mice. We believe our findings will help lead to new therapies for the prevention and treatment of breast cancer in women.”