Health Benefits Green Tea Pokorney

Health Benefits of Green Tea

Author: Marilyn Pokorney

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Substances in green tea known as catechins have been proven to be effective against many serious diseases.

In experiments with rats green tea catechin restricts the excessive buildup of blood cholesterol.

In Japan, where tea is drank several times a day cancer mortality statistics on Japanese people indicate that the death rate from cancer is significantly lower, for both men and women. Only 254 mg. of catechin begin to show effective results in the bloodstream. One cup of green tea contains 100 to 150 mg of catechin. In 1998, Chinese scientists presented details of a six-month study suggesting that drinking green tea improved
pre-cancerous oral lesions in patients.

A study by the American Journal of Clinical Nutrition showed that consumption of green tea may trigger weight loss by stimulating the body to burn calories and decreasing body fat. Dutch researchers found that women drinking more than 5 cups daily had a lower risk of severe arteriosclerosis.

In April 1999, researchers at Case Western Reserve University in Cleveland published a study claiming that drinking four or more cups of green tea a day may prevent rheumatoid arthritis amongst sufferers.

Green tea can help control diabetes. Experiments show that an extract of green tea to mice had the ability to lower blood sugar.

Japanese researchers have determined that catechin inactivates the influenza virus. Gargling with green tea is very effective in preventing influenza.

Doctors at the Aichi Cancer Institute have verified the fact that green tea catechin can inhibit the activity of the AIDS virus.

Green tea catechin suppresses the process of plaque formationand destroys the bacteria that forms plaque. Studies showed a reduction in cavities among grade school children who drank green tea after lunch. Green tea also kills the bacteria which causes bad breath.

Green tea has been demonstrated to kill seven strains of food poisoning bacteria including staphylococcus, clostridium and botulus. It is a good treatment for diarrhea.

Green tea can reduce and prevent high blood pressure by preventing angiotensin II, a substance in the blood, which causes constriction of the blood vessels causing high blood pressure.

By stimulating fat metabolism studies suggest that green tea extract may be useful for improving endurance capacity.”

The best way to get the disease-fighting nutrients in tea is to drink it freshly brewed after allowing it to steep for three to five minutes. Decaffeinated, bottled ready-to- drink, and instant teas have less of the healthful compounds.

Researchers caution that tea can’t be seen as a cure, but it could be viewed as a vitamin for the immune system.

Green Tea and Weight Loss

Green tea is beneficial for losing weight? Yes, believe it or not, increasingly you’ll find green tea (or green tea extract) included in the ingredients of a great many of the more popular weight loss supplements and concoctions on the market today.

And why are supplement makers so rushing to include green tea in their weight loss products?  Because the benefits of green tea are many…

Specifically, green tea extract often replaces the caffeine component of the standard ephedrine – caffeine – salicin (aspirin) fat burning stack. This makes it a fairly effective quality fat burner.

However, if that’s all green tea did, this article would be pretty short indeed. Lucky for us it has a great many other benefits — far and beyond what the usual caffeine laden cup of coffee could do. First, it’s a very effective anti-oxidant… just like the vitamin C you’ll find in a glass of orange juice and the beta-carotene in green veggies!  But researchers have suggested that the active ingredient (called epigallocatechin gallate), could be up to 200 times more powerful than vitamin E as an oxidant.

Green tea is also effective as a glucose regulator — meaning that it slows down the body’s rise in blood sugar following the consumption of a meal.

Green tea does this by decreasing the action of a certain digestive enzyme called amylase. This enzyme is used by the body to breakdown starches (carbs) that can cause blood sugar levels to increase dramatically following a meal. Along with a chromium, and possibly a vanadyl, green tea could be the missing link in a proper glucose management diet for diabetics.

Green tea has also helped aid weight loss by increasing the metabolic rate, causing those who use it to experience greater calorie burn.

A recent study further validates green tea’s effectiveness. A new study published in the American Journal of Clinical Nutrition (Vol. 81, No. 1, 122-129, January 2005), indicates that the consumption of a beverage rich in catechins (catechins are a major component of green tea extract) leads to both a lowering of body fat and of cholesterol levels.

More Cancer Evidence

Even More Evidence of Cancer Prevention!

by Anamika Holke

Throughout the course of a days dietary intake beverages can add a considerable portion of calories to the average diet.

The carbonated sodas that we all enjoy are, of course, high in calories (usually present in the form of sugary corn syrup) can contribute to obesity, tooth decay and other health problems.

The USDA’s 2005 dietary guidelines encourage us to switch to healthier alternatives of drinks and foods to moderate our intake of sugar. Janet King, chairwoman of the guideline committee, told food journalists to be on the lookout for a new set of beverage guidelines that have been submitted to the American Journal of Clinical Nutrition.  King recently gave a speech at the Association of Food Journalists’ annual conference in San Francisco.

Choosing beverages wisely can make the difference between a balanced diet and one that is out of whack. A 12-ounce can of regular soda adds 120 to 140 calories and zero nutrients to the diet. Although 100 percent fruit juices are a healthier choice, they also can tally up calories quickly. For instance, one cup of cranberry juice cocktail with sugar contains 147 calories.  Lighter juice versions with artificial sweeteners are also available.

In search of a zero-calorie beverage, many Americans have learned to guzzle unsweetened iced tea on a regular basis. In fact, in this country 40 billion of the 50 billion cups of tea consumed each year are served over ice, according to the Tea Council.

If you’re looking for zero calories, green tea is your best option.  It has possible health benefits unlike iced tea. It is rarely served with milk or sugar and contains powerful antioxidants known as polyphenols.  These antioxidants may help prevent some types of cancer.

It is thought that these polyphenols scavenge for free radicals before they have time to cause injury to the cells. Green tea has about 30 percent to 40 percent polyphenols compared to black tea that has just 3 percent to 10 percent polyphenols. The average cup of green tea contains 50 milligrams to 150 milligrams of polyphenols, according to the University of Maryland Medical Center (www.umm.edu).

The American Institute for Cancer Research conducts some research that focuses on the link between diet and health.  Their studies on lab animals have found that polyphenols can reduce the number and size of tumors. However, human studies have yet to reproduce the same results, leading the FDA to refuse health claims for green tea.

So should Americans try to adopt the green tea habit?

“Drinking massive amounts of green tea will never be able to save us from the ill effects of overeating a poorly balanced diet and living a sedentary lifestyle…. However, for those of us who would like to do a little more to reduce the risk of cancer, replacing three or four cups of coffee or soda per day with green tea is a reasonable step that may bring health benefits,” writes Karen Collins, a nutrition expert who wrote a column that appeared on the AICR’s Web site (www.aicr.org) in September.

Green tea is traditionally served hot in Asia and sometimes used as a health remedy.  Americans have acquired a taste for convenient health drinks.  Several versions of iced green tea have provided an on the go option instead of traditional hot green tea.

Green Tea and Hair Loss

Green Tea and Hair Loss and Testimonials for Hair Growth

by Michael Ganzeveld


One of the most popular organic herbal agents being used these days is green tea. The plant name for organic green tea is Camellia sinensis which originates in China, but very popular in Japan and other Asian countries. Green tea comes from the dried leaves of the tea plant.  It is different from black tea in that black tea is the fermented leaves from the same tea plant.  Organic green tea has been used in the last few years to combat a wide range of problems including (but not limited to) skin aging, intestinal ailments, as well as androgenetic alopecia.

No published studies have been done to demonstrate that green tea is of worth for hair growth, whether taken orally as a supplement or topically in a liquid form. Most people conclude by their own judgment that if organic green tea has all of these wonderful anti-oxidant effects, it must also be good for aging and hair loss.

The Active Ingredients Found in Organic Green Tea:

Purine alkaloids are in green tea, which is a big name for caffeine, not to mention theobromine and theophylline, which are other ingredients you find in most other teas. The catechins are the important compounds found in the unfermented tea leaves, and the primary ingredients thought to be so helpful for green tea. Catechins are known to have several medicinal properties.  One of which is that catechins cause the relaxation of blood vessels so that it may help cardiovascular activity through increased circulation.  Catechins are also known to inhibit and kill certain bacteria so it also has antibacterial benefits like garlic extract does. Most importantly, it is the anti-oxidant effects that people seem so enthralled with to help skin wrinkles, aging, energy and stamina, and yes, also hair growth. Green tea is also thought to help and be protective against cancers, such as stomach and colon cancers and other gastrointestinal cancers.

Green Tea and Hair Loss:

Using green tea to grow hair probably relates to the evidence for influencing circulating hormones in the body. A high intake of green tea correlates to higher levels of sex hormone-binding protein – or globulin, which carries hormones like testosterone around the body in a bound, unusable form so that tissues cannot use it directly. Testosterone is usually carried around the body by this binding protein, therefore, reducing levels of free testosterone, so that it cannot be converted to dihydrotestosterone (DHT) in the hair follicle, which is thought to shorten the hair cycle and cause hair loss in men. Green tea is thought to effect the 5a-reductase type I enzyme, which converts testosterone to DHT. There are two forms of 5a-reductase, and type I is the enzyme in higher amounts around the body, but it is the type II enzyme, which is thought to be responsible for most of the DHT formed in the hair follicle. Finasteride/Propecia effects or inhibits the type II form found in hair follicle.

In any case, the 5a-reductase enzymes can be confusing when you try to figure out what type I does and what type II does and what the difference is for hair growth. From a hair growth perspective, both can be important, it is just that Merck makes a big hype about the fact that their product, finasteride/Propecia inhibits type II and this is supposed to be the main enzyme form found in hair follicle, however, research work done in my lab a few years ago, revealed both forms in hair follicle, and also sebaceous glands. If anything, the type I enzyme is found mostly in sebaceous gland, which is just next door to the hair follicle and can also effect the level of male hormones around the hair follicle.

Again, no clinical studies have been done to show efficacy of green tea for hair loss, so it is up to the user to be aware of the cost, side effects, the fact that no proper dose level is known to effect hair growth, etc.

Potential Side Effects of Using Green Tea for Hair Loss:

Care should be taken to those with sensitive stomachs, since the caffeine, tannins, acids, etc, can cause stomach irritation. Many people do resort to taking high doses of herbals, so that 1.5 g of caffeine per day in green teas can cause restlessness, irritability, sleeplessness, palpitations, vomiting, headache and other symptoms. Those who consume more than 300 mg or 5 cups of tea beverage can lead to the above symptoms, however fatal doses are most likely not possible.

Other uses for green tea:

Green tea is most widely known in cosmetic preparations for wrinkles on the face. The price of topical creams, lotions, potions with green tea is off the wall, and again, I haven’t seen any real evidence that using these agents, topically or orally really helps in reversing wrinkles, but ladies will stand in line at cosmetic counters, not to mention popular shopping networks to buy the stuff for big bucks.

Interesting comment:

Minoxidil or Rogaine is also thought to work in stimulating hair growth because of its oxidative-reducing capacity for cofactors in the metabolic pathway. I would think that if green tea works to help hair growth, it would be in a similar way to minoxidil, rather then influencing the 5a-reductase enzymes. Who knows? Not enough research has been done to really find out if it works and what mechanisms it may have in skin.

Conclusion:

Try it if you want to, but again with any hair-growing agent, it is advised to use for a 6 month to 12-month period for hair growth. I’d be interested to know if it helped with hair shedding, so if you try it, let me know what you think. Remember, we usually shed about 100 hairs per day (shower, hair brush, comb, pillow, floor etc), so if you see reduced shedding, there may be something to it.

Moms and Smoking

Moms and Smoking; Apple Juice and Colon Cancer; Green Tea and Skin Cancer 

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by Robert A. Wascher, M.D., F.A.C.S.
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THE POWER OF NICOTINE: SMOKING MOM-TO-BE

The British Medial Journal: By now, everyone knows (or should know) that nicotine is enormously addictive, and that smoking is the single greatest cause of preventable disease and death in the world. It is also common knowledge that smoking during pregnancy subjects a mother’s unborn baby to the very same genetic mutations that are known to arise in smokers. Moreover, other complications now known to be associated with smoking by pregnant mothers include abnormal development of the placenta, low birth-weight, cleft palate and cleft lip, and a doubling of the risk of babies dying from Sudden Infant Death Syndrome (SIDS). Asthma, learning disabilities and behavioral disorders are among the other long-term ailments that have also been strongly linked to smoking during pregnancy, and smoking following delivery.

In view of these seemingly incontrovertible facts, I am always stunned and, I must confess, angry when I see an obviously pregnant woman smoking (i.e., as opposed to my baseline sense of astonishment whenever I see anyone, pregnant or not, smoking…). Although I certainly understand the potent addictive qualities of nicotine, the obvious and profound conflict between maternal instinct and drug addiction (the arbitrary legality of tobacco in no way detracts from the fact that nicotine is an addictive drug that makes people “feel good”) is so stark, in my mind, that I never fail to become upset when I see a mom-to-be puffing away.

In the face of this enormous conflict between smoking and pregnancy, an interesting new study has looked at the impact of in-home motivational counseling on tobacco cessation among expectant mothers who smoke. A group of 762 pregnant smokers were randomly divided into two groups for the purposes of this study. All of the women received standard health counseling during their prenatal visits, while the 351 women in the intervention group also received regular in-home motivational counseling visits from specially trained midwives. In addition to serially interviewing all of the 762 women regarding their progress with smoking cessation, all of the women also had blood or saliva collected to measure the concentration of a metabolic breakdown product of nicotine.

In this group of smokers who, one would think, should be among the most motivated to quit, only 4.8% in the intervention group quit, while essentially the same number in the control group (4.6%) quit. Thus, in this group of pregnant women, intensive in-home motivational counseling had absolutely no discernible impact on smoking cessation. As surprising as this disappointing outcome might be to some people, the results of this study mirror my own experiences as a physician over nearly two decades now. Smokers subject not only themselves to the well-known health risks of smoking, in order to continue their nicotine addiction, but many of them also choose to subject their children (born and unborn) to the same severe health risks as well….

APPLE JUICE & COLON CANCER PREVENTION

Carcinogenesis: There is a great deal of research underway at this time, looking at how dietary and supplemental products might help to prevent disease, including cancer. Unfortunately, most of this research has either not found significant health benefits for such products, or the apparent benefits observed in a culture dish in a lab, or in mice, have not been successfully reproduced in humans as of yet. (Indeed, this area of research is so confusing, and seemingly contradictory, to most people, that I am currently writing a book on the subject: “What You Don’t Know Can Kill You: A Clinically Proven Plan to Reduce Your Risk of Dying from Cancer!”) Because of these factors, it is wise to approach each new research paper with a healthy bit of skepticism. However, studies that look into the biochemical effects of products and substances thought to have anticancer effects are of special concern to me, as much of the clinical literature looking at cancer prevention in humans is survey-based and, consequently, the results of such studies are not very compelling, scientifically.

Unfiltered apple juice, containing more of the solid components of apple pulp than filtered, or clear, apple juice, was tested in rats in an effort to identify any anticancer properties in the colons of these animals. Rats were randomized to receive drinking water alone, clear filtered apple juice, or unfiltered cloudy apple juice, while receiving injections of a chemical known to cause colon cancer in rodents. After 7 weeks, microscopic examination of the animals’ colonic lining was undertaken. Under the microscope, specific precancerous changes in the cells of the rats’ colons were significantly less common in the animals that had consumed the unfiltered cloudy apple juice when compared to the animals that had consumed plain water or clear filtered apple juice. At the same time, other specific premalignant changes were less common in all of the animals that received apple juice, both filtered and unfiltered. This is an interesting finding, as both filtered and unfiltered apple juice are rich in compounds known as polyphenols, which are thought to have anticancer activity. The findings of this study, therefore, suggest that there may be other important compounds within the pulp of apples that, likewise, possess potential anticancer properties. Although the findings of this study are a very long way from proving that apple juice, whether filtered or unfiltered, might reduce a person’s risk of developing colon cancer, it is still a very interesting little study, and additional similar studies should be undertaken with human volunteers.

GREEN TEA & CAFFEINE MAY REDUCE SKIN CANCER RISK

Carcinogenesis: Another dietary supplement that has garnered considerable attention within the cancer prevention community is green tea, which, like apples, is also known to be rich in polyphenols. A new study, involving mice, looked at the effects of green tea, and caffeine, on the prevention of early precancerous changes in the skin of mice subjected to intense ultraviolet light (UVL) skin exposure. Mice were treated, alternatively, with oral green tea or oral caffeine solution during the period of UVL irradiation, and their irradiated skin was then analyzed under a microscope, looking for characteristic mutations in a protein known as p53, which is an early event in the development of UVL-induced skin cancer. This study found that, compared to a group of mice that received only water, the mice that consumed either green tea or caffeine experienced a 40% reduction in the number of precancerous patches within UVL-exposed skin. Once again, this is an interesting laboratory study in nonhuman animals, and the findings of this elegant little study may not effectively translate into humans. Still, the results of this experiment raise the possibility that oral green tea or caffeine supplements might reduce the early precancerous changes in UVL-exposed skin when taken at the time of exposure. As always, however, avoidance of the sun’s rays, particularly during peak UVL periods, between 9 AM and 4 PM, is the best method of preventing UVL-induced skin cancer, especially in fair-skinned individuals.

SECONDHAND SMOKE EXPOSURE IN CHILDREN: ANOTHER RISK FACTOR FOR DIABETES AND HEART DISEASE?

Circulation: The so-called Metabolic Syndrome refers to a constellation of abnormalities that include obesity, abnormal cholesterol levels, high blood pressure, and elevated sugar in the blood (sometimes also referred to as “insulin resistance,” or “pre-diabetes”). Following the recent explosion in both adult and childhood obesity in the United States, the prevalence of the Metabolic Syndrome in both populations is the subject of much concern within the public health community. This syndrome is associated with a very high incidence of subsequent cardiovascular disease, to include stroke, as well as diabetes, high blood pressure, and early death.

A new study, involving 2,273 adolescent subjects ages 12 to 19, evaluated the presence or absence of household smokers, the self-reporting of smoking by the adolescent subjects, and the measured blood levels of nicotine byproducts in the blood of the adolescents. Among the adolescents with no tobacco exposure (either firsthand or secondhand), 1.2% met the criteria for Metabolic Syndrome. Among the kids exposed to secondhand smoke alone, 5.4% met the criteria for Metabolic Syndrome. Among the subjects that smoked themselves, 8.7% met the criteria for Metabolic Syndrome. Following statistical analysis to balance other risk factors (e.g., diet, level of exercise, family history of cardiovascular disease or diabetes, etc.), adolescents who were chronically exposed to secondhand smoke were found to have nearly 5 times the risk of developing Metabolic Syndrome when compared to kids who were not exposed to tobacco smoke in any form, while adolescents who actively smoked themselves were at more than 6 times the risk of developing Metabolic Syndrome.

Given that smoking and obesity are the two leading causes of preventable death in the United States, the finding that exposure to tobacco smoke, both firsthand and secondhand, is associated with an increased risk of the Metabolic Syndrome is ominous, indeed….

Dr. Robert A. Wascher

Separating Fact from Fiction

Facts and Fiction Surrounding Green Tea

When Hyun Jee Suh (22) was studying for the LSAT exams she habitually drank several cups of cold green tea a day after having heard it was good for dieting and for healthy skin and also that it was better than water.  But after ten days of this regimen her stomach ached and her digestion was poor.  Choe Seong-hee of Dong-eui University’s Department of Food and Nutrition advises that that’s what happens if you drink too much of the faddish drink on an empty stomach.  Basically, another instance of “too much of a good thing.”

Should I take my tea hot or cold?

Eastern medicine specialists advise hot green tea over cold because its “cold” elements already bring down body temperature. For people of the “Minor Yin” body type, who get cold easily, it’s best not to drink green tea when they experience indigestion after eating cold food. In Eastern medicine, different medicines have been used to treat diseases depending on “body type,” of which there are four — Major Yang, Major Yin, Minor Yang and Minor Yin. Lee Chang-hun of Kyung Hee University’s Kangnam Korean Hospital says people with bodies with a lot of heat should also avoid cold green tea.

Is more tea the better?

One or two cups is fine.  If you drink more than that the acidic tannin in green tea can irritate an empty stomach, just like drinking orange juice can irritate some peoples stomach. Tannin can prevent the stomach lining of some people with gastro-intestinal disorders (such as gastric ulcers) from repairing itself.  Oxidized oolong or black tea make the tannin insoluble so they are fine.  Moreover, too much caffeine can mean you lose too many minerals in your urine since this is the method by which the body excretes them.

What happens when green tea and milk combine?

Because tannin merges with inorganic materials, it can interfere in the absorption of calcium. The effects are not of a scale that should worry you, but you shouldn’t let growing children drink green tea right after they’ve eaten calcium-rich food. Mothers should avoid mixing green tea into their babies’ powdered milk, and pregnant mothers and babies under five months should avoid it because their capacity to discharge caffeine is lower.

Is tea good for constipation?

The effects of green tea made from soaked leaves and from powder are different. In the case of tea from leaves or tea bags, only the minerals seep out into the water. The dietary fiber that eases constipation remains in the leaf itself and does not enter the body, so it has no effect on constipation.

Is green tea beneficial for losing weight? 

A cup of green tea contains zero calories, and it naturally decreases the amount of cholesterol stored in the body. The caffeine and amino acids stimulate the brain and increase your body’s metabolism so it can lead to weight loss. Yet no matter how good a food is it is best not to consume too much of it. The best policy is to maintain a healthy diet and use common sense when judging consumption.

Green Tea As the Alternative Brew

Third International Scientific Symposium on Tea and Human Health: Role of Flavonoids in the Diet

As time goes on additional new findings strengthen the relationship between green tea and a decreased risk of certain types of cancer!

Reseach scientists from around the globe convened yesterday in Washington, DC for the Third International Scientific Symposium on Tea & Human Health: Role of Flavonoids in the Diet to review the latest findings on the potential health benefits of tea, including new studies on promoting heart health and reducing the risk for cancer. The latest data provide further evidence of tea’s potential disease-fighting capabilities. Major research developments since the Second Symposium on Tea & Human Health, held in 1998, include new results that suggest:

· Tea may reduce Low Density Lipoprotein (LDL, or “bad” cholesterol) levels by 10 percent
· Consumption of as little as four cups of tea per day may contribute to cardiovascular health by improving endothelial function, as seen in clinical studies
· Tea may reduce oxidative stress, as indicated by decreases in DNA damage in smokers
· Tea consumption is linked with a 60 percent decrease in rectal cancer among women

The symposium, which was sponsored by the American Cancer Society, the American College of Nutrition, the American Health Foundation, the American Society for Nutritional Sciences, the Food and Agriculture Organization, the Linus Pauling Institute and the Tea Council of the U.S.A., was held at the United States Department of Agriculture (USDA). Leading researchers from around the world joined American scientists in presenting the latest clinical, laboratory and epidemiological data on the role of tea in promoting healthfulness and reducing the risk of disease.

“As investigators continue to study the multiple effects that tea has on human health, more research supports tea’s potential in helping to reduce the incidence of major diseases,” said the meeting’s co-chair, Jeffrey Blumberg, PhD, Professor, Friedman School of Nutrition Science and Policy, and Chief, Antioxidants Research Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston. “The scientific community is making tremendous strides in discovering the potential for flavonoids in black and green tea and other plant foods to promote health and reduce the risk of certain chronic diseases, findings which could have significant implications for public health.”

Studies Suggest Tea Consumption May Lower “Bad” Cholesterol
The results of a new clinical study suggest that tea consumption may decrease LDL cholesterol by 10 percent when combined with a “Step I” type diet, moderately low in fat and cholesterol, as described by the American Heart Association and the National Cholesterol Education Program. The study, conducted at the USDA Beltsville Human Nutrition Research Center in Beltsville, MD, is the first investigation of tea in which the subjects’ diets were precisely controlled by having them eat meals prepared at the research facility. In addition to the “Step I” diet, all subjects consumed five cups of either caffeinated tea, a placebo beverage with color and flavor closely matching that of the tea, but having no caffeine, or a similar placebo beverage with caffeine added to the same concentration as in the tea. “This clinical trial is one of the first to show significant benefits of tea on blood cholesterol,” said Joseph Judd, PhD, Acting Director, Beltsville Human Nutrition Research Center, and the study’s lead researcher. “The controlled diet allowed us to closely examine the effects of tea drinking in conjunction with a healthy diet on cholesterol levels free from the interference by variation in other nutrients or components of the diet.”

These new developments in tea research add to the growing body of evidence suggesting that tea consumption positively impacts cardiovascular health in several different ways, with as little as two to four cups per day. Another study, published in the May 6, 2002 issue of Circulation: Journal of the American Heart Association, found that study participants who drank four cups of tea per day had a significantly lower risk of death following a heart attack. Additional research suggests that tea flavonoids may support endothelial function, an important indicator of cardiovascular health. More research is necessary to conclude that tea may be used as a preventive measure to combat the risk of heart disease, but the results so far are extremely promising.

New Developments in Cancer Research Lung Cancer
In the first intervention study using tea, preliminary findings suggest that smokers who drank tea had significantly lower levels of oxidative DNA damage. Oxidative stress to DNA is implicated in a multitude of chronic diseases, including cancer. In this clinical study, smokers drank four cups of decaffeinated green tea, decaffeinated black tea or water for four months. Researchers then looked at several biomarkers of oxidative stress, or DNA damage. Preliminary results found that smokers who drank green tea showed a significant decrease in urinary biomarkers of oxidative DNA damage. Researchers
have also observed similar results in animal studies, in which tea inhibited tobacco-induced lung tumor formation. “We know that smokers’ bodies sustain a high level oxidative damage and are at risk for certain cancers,” said Iman Hakim, MD, PhD, MPH, Division Director, Health Promotional Sciences, Arizona Cancer Center and Research Associate Professor of Public Health, College of Public Health, University of Arizona. “Because this population has elevated levels of oxidative damage at baseline, we are better able to observe the effects that tea consumption has on oxidative stress.”

Rectal Cancer
According to an epidemiological study conducted in Russia to determine the protective nature of black tea against rectal cancer, women who consume high levels of tea were shown to have a 60 percent reduction in the risk of rectal cancer, as compared to women who drank relatively low amounts of tea. Researchers identified patients recently diagnosed with rectal cancer and questioned them about their tea-drinking habits, then divided the participants into three groups based on the amount of dry tea used per month: low consumption, less than 80g dry tea per month; moderate consumption, 80 – 160g dry tea per month; and high consumption, more than 160g dry tea per month. The Russian population was selected, not only because tea drinking is an essential part of the culture, but also because of the traditional method in which tea is prepared. As is the custom, black tea is brewed at a high concentration, then consumed in a diluted form throughout the day. Instead of measuring tea consumption in terms of fluid measures, intake was measured by the amount of dry tea used to make the tea concentrate. In addition to the 60 percent reduction in risk of rectal cancer found in heavy tea-drinking women, researchers found that women who were moderate tea-drinkers had a 52 percent reduction in the risk of rectal cancer as compared to women in the low consumption group. Although men were also recruited for the study, the findings were much weaker, possibly due to the men’s high volume of alcohol intake.

These new findings are an important step in determining the potential role of tea components in cancer prevention and complements previous studies that have found tea drinking to be associated with a decreased risk of certain cancers. More research is necessary before a definitive link can be made, but the current research looks promising.

Mechanism of Action and Bioavailability of Tea Flavonoids 
While the established body of tea research strongly suggests that tea consumption offers a wide variety of health benefits, ranging from the promotion of heart health and reduced risk of some forms of cancer, the actual mechanisms by which the benefits are wrought remains under investigation. In vitro studies suggest that tea flavonoids protect against oxidation, but there may be other mechanisms by which tea components function once they are absorbed into the body.

During digestion, flavonoid molecules undergo biochemical changes. Since these compounds are modified in the gut, flavonoids may still protect against oxidative stress, but may function by other mechanisms as well in vivo. In vivo studies suggest that flavonoids interrupt the pathway of oxidative stress and intercept the “message” for apoptosis, or cell death.

Black tea’s flavonoids are complex in structure and appear to be absorbed at different points in the body. Some of the larger molecules are not absorbed in the stomach or small intestines, but remain intact until they reach the colon, where they are partly absorbed into the bloodstream. The remaining flavonoids may act as antioxidants and reduce the risk of colon cancer. Because black tea’s flavonoids remain intact through much of the gastrointestinal tract, it seems that the flavonoids may have potential benefits at various points throughout the gut. Conversely, the principle constituents of green tea, are simple flavonoids, called catechins, which are quickly absorbed into the body after consumption. “Because green and black tea flavonoids appear to be absorbed and metabolized at different points throughout the digestion process, flavonoids may have an even wider range of protective benefits to various body systems than originally thought,” explained Dr. Blumberg.


The ongoing scientific exploration of the health benefits of drinking green tea has led to a growing body of research that points to tea as being an important contributor to overall health. Research continues to show that flavonoids seem to have a potent effect in maintaining the health and function of cells and physiological systems – and tea is a major source of flavonoids in the human diet.

“The research presented at this year’s symposium further extends the scientific evidence that tea may have a favorable effect on the cardiovascular system and may positively impact health in many other ways, including reducing the risk for some cancers,” said Dr. Blumberg.

Looking towards the future, researchers plan to probe deeper into the various mechanisms by which tea flavonoids function in the body and the implications these mechanisms have on human health and disease prevention. Clinical trials now underway and being planned will provide further important information about the role of tea in health promotion.