Tea and Your Health

 There is an ever growing body of research regarding tea’s contribution to our health involving study after study being conducted by researchers in the United States, Canada, Europe, China and Japan. Our mission is to disseminate scientifically accurate and up-to-date information to you.

We utilize information and studies that have been performed and or reported by the National Institutes of Health, National Center for Complementary and Alternative Medicine, The Linus Pauling Institute at Oregon State University, National Cancer Institute and MD Anderson Cancer Center and the American Journal of Clinical Nutrition to name a few. The scientific studies are valuable because they are conducted using rigorous research methods, they undergo peer review and the results of the study can be independently verified by being repeated by another researcher. While many of the studies have involved animal studies, the body of evidence is supporting more studies being conducted using human trials.

We encourage you, as an informed consumer, to do your own research in learning about what health benefits are being studied related to tea consumption. We are aware that there are many websites on the internet, reporting, what they believe to be factual, the health benefits of tea.  Frankly, some of the information out there is just not accurate and is misleading. We give credit to our sources for the information so that you know we have not just simply pulled a study out of thin air and posted it.

 

WHITE TEA DIET? 

Could a simple cup of tea hold the key to losing weight?

Maybe, report German researchers – but only if people consume the more pristine form of the drink made from the buds and early leaves of the tea plant.

Their study shows this type of tea – known as white tea – has potent effects on human fat cells.

The investigators tested the ability of white tea to influence fat cells in a laboratory study. When human cells were exposed to an extract of white tea, generation of new fat calls – called adipocytes – was curtailed and existing cells were more likely to break down the fat they already contained.

The researchers believe white tea works best because it contains more of the ingredients thought to impact human health than either green or black tea, including methyl-xanthine and epigallocatechin-3-gallate.

“In the industrialized countries, the rising incidence of obesity-associated disorders including cardiovascular diseases and diabetes constitutes a growing problem,” study author Marc Winnefeld was quoted as saying. “We’ve shown that white tea may be an ideal natural source of slimming substances.”

SOURCE: Nutrition and Metabolism, published online April 30, 2009

 

GREEN TEA HELPS LEUKEMIA PATIENTS

Green tea's active ingredient epigallocatechin gallate (EGCG) shows promise in helping leukemia patients battle cancer.

The Mayo Clinic's trial studied 33 patients taking the green tea extract in capsule form twice daily, ranging in doses from 400 to 2,000 milligrams. Patients were able to withstand EGCG in very high doses, so high that researchers believe they have not yet reached a maximum dose.

“The majority of individuals who entered the study with enlarged lymph nodes saw a 50 percent or greater decline in their lymph node size," Tait Shanafelt, M.D., Mayo Clinic hematologist and lead author of the study was quoted as saying.

CLL, the most common type of leukemia in the United States, currently does not have a cure. Researchers hope that EGCG can strengthen patients' treatments when combined with additional therapies.

SOURCE: Journal of Clinical Oncology, May 26, 2009

 

GREEN TEA AND CANCER RESEARCH CONTINUES

In a recent study, MD Anderson researchers examined the effects of green tea extract on people with a precancerous condition called oral leukoplakia. Results were encouraging, showing less progression towards development of cancer in more than half of those who took the extract. Vassiliki Papadimitrakopoulou, MD, professor in the Department of Thoracic/Head and Neck Medical Oncology and the study’s senior author, cautions that this initial trial enrolled few participants and still warrants more research. “While still very early, and not definitive proof that green tea is an effective agent, these results certainly encourge more study for patients at highest risk for oral cancer,” he says.

SOURCE: Inside Integrative Medicine, August/September 2010, MD Anderson Cancer Center

 

GOT TEA? PICK CUP OVER BOTTLE FOR HEALTH BENEFITS

Think swigging back a bottle of iced tea will provide the same health benefits as a cup of green tea? Think again. Researchers found that health-conscious consumers may not be getting what they pay for in many popular beverages.

Scientists reported that bottled tea beverages that account for $1 billion in annual sales in the U.S., contain fewer polyphenols or healthy antioxidants than a single cup of home-brewed green or black tea. Some bottled teas contain such small amounts that consumers would have to drink 20 bottles to get the polyphenols present in one cup of tea.

"Consumers understand very well the concept of the health benefits from drinking tea products," Shiming Li, Ph.D., an analytical and natural product chemist at WellGen, Inc. in North Brunswick, N.J., was quoted as saying. "However there is a huge gap between the perception that tea consumption is healthy and the actual amount of the healthful nutrients found in bottled tea beverages. Our analysis of tea beverages found that polyphenol content is extremely low."

Researchers found that in addition to the low polyphenol content, bottled tea contains large amounts of sugar as well.

Li and his colleagues measured the level of polyphenols - a group of natural antioxidants linked to anti-cancer, anti-inflammatory, and anti-diabetic properties - of six brands of tea purchased from supermarkets. Half of the brands contained virtually no antioxidants while the others had such infinitesimal amounts that they carried no health benefits. With no industry or governments standards or guidelines for measuring and listing the polyphenolic compounds in a given product, manufacturers can write whatever they want.

The six teas analyzed contained 81, 43, 40, 13, 4, and 3 milligrams (mg) of polyphenols per 16-ounce bottle. The average cup of home-brewed green or black tea, which costs mere cents, contains 50-150 mg of polyphenols.

"Polyphenols are bitter and astringent, but to target as many consumers as they can, manufacturers want to keep the bitterness and astringency at a minimum," Li said. "The simplest way is to add less tea, which makes the tea polyphenol content low but tastes smoother and sweeter."

SOURCE: 240th National Meeting of the American Chemical Society, August 24, 2010

 

TEA AND CANCER PREVENTION: STRENGTHS AND LIMITS OF THE EVIDENCE

Tea contains polyphenol compounds, particularly catechins, which are antioxidants and whose biological activities may be relevant to cancer prevention. Tea also contains alkaloids (caffeine, theophylline and theobromine), amino acids, carbohydrates, proteins, chlorophyll, volatile organic compounds (chemicals that readily produce vapors and contribute to the odor of tea), fluoride, aluminum, minerals and trace elements.2 The polyphenols, a large group of plant chemicals that includes the catechins3 are thought to be responsible for the health benefits that have been traditionally associated with tea, especially green tea. The most active and abundant catechin in green tea is epigallocatechin-3-gallate (EGCG).

Let’s look at some definitions:

1. Alkaloids: A group of nitrogen-containing organic compounds of great importance because of their medicinal and other properties. Caffeine is an alkaloid of the methyl-xanthine group, which has a stimulating effect, both physical, and mental, on humans. The presence of caffeine in tea leaf is the major reason tea is used as a beverage.

  • Caffeine: 1,3,7-trimethyl-xanthine or caffeine (C8 H10 N4 O2) is an alkaloid that occurs in some 60 plants including coffee, tea, mate, guarana, chocolate and kola nut. It is a colorless compound with a slightly bitter taste and acts on the central nervous system as a stimulant and a diuretic. Unlike coffee, the caffeine in tea produces no jolt or let down.
  • Theophylline: Found in very small amounts in tea, it has a stronger effect on the heart and breathing than does caffeine. It is a cardiac stimulant, smooth muscle relaxant, diuretic and vaso-dilator. The theophylline used in medicine is made from tea or coffee extracts.
  • Theobromine: 3,7-dimethyl-xanthine is the same class of compounds as caffeine. It occurs naturally in tea and in many other plants found throughout the world. Theobromine has a longer half-life than caffeine, around 7-8 hours. It is marketed as a weight loss aid and as a stimulant. It has diuretic properties similar to those of caffeine.

2. Polyphenols: A wide range of naturally occurring chemical compounds in tea leaf and liquor. Certain of these are oxidized in the manufacture of oolong an black teas. Unoxidized polyphenols are responsible for the slightly bitter taste sometimes experienced in green tea. Catechins and Flavanols account for 75% of the polyphenols in tea leaf.

  • Catechin:The primary polyphenol found in tea which accounts for 30% - 40% of dry leaf weight. The four main catechins in green tea leaf are: Gallocatechin (GC), Epigallocatechin (EGC), Epicatechin (EC) and Epigallocatechin Gallate (EGCG). The EGCG give green tea antimicrobial properties which defend the body against various food-poisoning microbes.
  • Flavanols:Substances in tea which may be more closely defined as catechins. They are colorless plant pigments that with oxidation readily turn brown. Flavanols, of which six have been identified in the leaf, account for over three-quarters of the polyphenols in the tea.
  • Thearubigins:Red and brown compounds formed by condensation of theaflavins during oxidation. Associated with the strength, body and color of a tea infusion.
  • Theaflavins: Yellow compounds formed during the process of tea oxidation. These are associated with quality, briskness and brightness of the liquor.

Black tea contains much lower concentrations of these catechins than green tea.4 The extended oxidation of black tea increased the concentrations of thearubigins and theaflavins Oolong tea contains a mixture of simple polyphenols, such as catechins and complex polyphenols.1 White and green tea contain similar amounts of EGCG, but different amounts of other polyphenols9.  The polyphenol concentration of any particular tea beverage depends on the type of tea, the amount used, the brew time and the temperature.2 The highest polyphenol concentration is found in brewed hot tea, less in instant preparations and lower amounts in iced and ready to drink (RTD) teas.2 As the percentage of of tea solids, (i.e. dried tea leaves and buds) decreases, so does the polyphenol content.5 Decaffeination reduces the catechin content of teas9.

Tea has long been regarded as an aid to good health and many believe it can help reduce the risk of cancer. Most studies of tea and cancer prevention have focused on green tea.7 Although tea and or tea polyphenols have been found in animal studies to inhibit tumorigenisis (formation of tumor) at different organ sites, including skin, lung, oral cavity, esophagus, stomach, small intestine, colon, liver, pancreas and mammary gland,8 the results of human studies – both epidemiologic and clinical studies – have been inconclusive.

More than 50 epidemiologic studies of the association between tea consumption and cancer risk have been published since 2006. The results of these studies have often been inconsistent, but some have linked tea consumption to reduced risks of cancers of the colon, breast, ovary, prostate and lung. The inconsistent results may be due to variables such as differences in tea preparation and consumption, the types of tea studied (green, black or both), the methods of tea production, the bioavailability of tea compounds, genetic variation in how people respond to tea consumption, the concomitant use of tobacco and alcohol and other lifestyle factors that may influence a person’s risk of developing cancer, such as physical activity or weight status.

Source: National Cancer Institute 11/17/2010

Selected References:

1. Mukhtar H, Ahmad N. Tea polyphenols: Prevention of cancer and optimizing health. American Journal of Clinical Nutrition 2000; 71(6 Suppl):1698S–1702S. [PubMed Abstract]

2. Cabrera C, Giménez R, López MC. Determination of tea components with antioxidant activity. Journal of Agricultural and Food Chemistry 2003; 51(15):4427–4435. [PubMed Abstract]

3. Cabrera C, Artacho R, Giménez R. Beneficial effects of green tea―a review. Journal of the American College of Nutrition 2006; 25(2):79–99. [PubMed Abstract]

4. Wu AH, Yu MC. Tea, hormone-related cancers and endogenous hormone levels. Molecular Nutrition and Food Research 2006; 50(2):160–169. [PubMed Abstract]

5. Peterson J, Dwyer J, Jacques P, et al. Tea variety and brewing techniques influence flavonoid content of black tea. Journal of Food Composition and Analysis 2004; 17(3–4):397–405. [Journal Abstract]

6. Henning SM, Fajardo-Lira C, Lee HW, et al. Catechin content of 18 teas and a green tea extract supplement correlates with the antioxidant capacity. Nutrition and Cancer 2003; 45(2):226–235. [PubMed Abstract]

7. Lambert JD, Yang CS. Mechanisms of cancer prevention by tea constituents. Journal of Nutrition 2003; 133(10):3262S–3267S. [PubMed Abstract]

8. Yang CS, Maliakal P, Meng X. Inhibition of carcinogenesis by tea. Annual Review of Pharmacology and Toxicology 2002; 42:25–54. [PubMed Abstract]

9. Santana-Rios G, Orner GA, Xu M, Izquierdo-Pulido M, Dashwood RH. Inhibition by white tea of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine-induced colonic aberrant crypts in the F344 rat. Nutrition and Cancer 2001; 41(1 and 2):98–103. [PubMed Abstract]

 

DRINK TO YOUR HEALTH

Tea speeds up your metabolism, which can help you maintain a healthy weight. Even better, tea’s antioxidants may help your body get rid of toxins and prevent abnormal cells from turning into cancer, says the National Cancer Institute.

1. To get your fill of antioxidants, drink white tea. Green tea is a good second choice. But black tea is heavily processed, so it has fewer cancer-fighting antioxidants.

2. Avoid sugars and sweeteners because they add extra calories.

3. Limit yourself to no more than 40 ounces of unsweetened tea per day and drink lots of water.

4. Herbal teas are not actually tea because they do not contain Camellia sinensis. They do not offer the same prevention perks as green, white or even black tea.

SOURCE: Focused on Health,  April 2011, MD Anderson Cancer Center

 

GREEN TEA + TAI CHI = HEALTHY BONES

Green tea combined with a fitness activity known as tai chi may improve bone health and reduce inflammation in postmenopausal women, according to a new study.

Dr. Chwan-Li Shen, an associate professor and a researcher at the Laura W. Bush Institute for Women's Health at Texas Tech University Health Sciences Center, has spent over two decades studying how Eastern lifestyle traditions may benefit Westerners.

In her most recent research, Shen studied 171 postmenopausal women who had weak bones. She looked at the effects of green tea polyphenols (GTP) combined with tai chi -- a traditional Chinese form of moderately intense aerobic activity that employs the mind-body philosophy.

The participants were divided into four groups: a "Placebo" group that received starch pills and no tai chi; a "GTP" group that received green tea polyphenols (500 mg/day) and no tai chi; a "Placebo + TC" group that received a starch pill and tai chi (3 times a week); and a "GTP + TC" group that received green tea polyphenols and tai chi.

Results showed consumption of GTP at a level equivalent to about 4-6 cups of green tea per day and participation in tai chi independently enhanced markers of bone health by three and six months. A similar effect was found for muscle strength after six months. Participants taking tai chi classes also reported significant beneficial effects in quality of life and improved emotional and mental health. GTP and tai chi also had a substantial effect on biological markers of oxidative stress, which is a precursor to inflammation.

SOURCE: Experimental Biology Meeting, April 10, 2011

 

NEW STUDIES PROVE PROFOUND HEALTH BENEFITS OF TEA

20 Sep 2012

WASHINGTON, D.C.

New findings released at 5th International Scientific Symposium on Tea & Human Health reveal tea to have preventative health benefits including reduced risk of cardiovascular disease as well as stroke and heart attack.

Leading nutrition scientists from around the world convened at the United States Department of Agriculture Wednesday to present the latest research supporting the role of tea in benefiting and promoting better health.

The Tea Association of Canada compiled the overview that follows.

Interest in tea's potential health benefits has grown exponentially. In just the past five years there have been more than 5,600 scientific studies on tea, forming a substantial body of research on this world wide consumed beverage.

“There is now an overwhelming body of research from around the world indicating that drinking tea benefits human health,” says Dr. Carol Greenwood, who is a Professor in the Department of Nutritional Sciences at the University of Toronto and a Senior Scientist at the Rotman Research Institute at Baycrest.

Dr. Greenwood, an expert on the relationship between diet, nutrition and brain health, went on to say “the compounds in tea appear to impact virtually every cell in the body in a positive health outcome, which is why the consensus emerging from this symposium is that drinking at least a cup of clear green, black, white or oolong tea a day can contribute significantly to the promotion of public health.”

Of particular interest to Dr.ds Greenwood and the medical community was the numerous heart health studies presented that Tea supports heart health and healthy blood pressure, and appears to be associated with a reduced risk of cardiovascular disease, including stroke and heart attack.

New research presented by Claudio Ferri, MD, University L’Aquila, Italy, found in 19 normotensive and 19 hypertensive individuals that black tea was able to reduce blood pressure.  In the hypertensive patients, black tea appeared to counteract the negative effects of a high-fat meal on blood pressure and arterial blood flow. Hypertensive subjects were instructed to drink a cup of tea after a meal that contained .45 grams fat/lb. body weight. The results suggest that tea prevented the reduction in flow mediated dilation (FMD), the arterial ability to increase blood flow that occurs after a high-fat meal. In a previous study conducted by Ferri, tea improved FMD from 7.8 to 10.3%, and reduced both systolic and diastolic blood pressure by -2.6 and -2.2 mmHg, respectively, in study participants.

 Also of interest among the findings is research suggesting that green tea and caffeine may trigger energy expenditure that may promote weight loss. Another study illustrates how tea may help counter the adverse effects of high-fat foods on blood vessels, which could possibly reduce the risk of atherosclerosis, the most common cause of death in the North America.

Tea and Body Weight

Obesity is the largest public health concern in North America and there are few strategies that provide long-term success.  New research on tea catechins suggests that they may provide a benefit in maintaining body weight or promoting weight loss.

Tea and Bone and Muscle Strength

Osteoporosis is a major public health concern for many older women and men as the disease is responsible for two million fractures a year and 300,000 hip fractures in 2005. The disease leads to loss of mobility, independence and reduces quality of life for many older Americans.

Researchers at Texas Tech University Health Sciences Center conducted studies with 150 postmenopausal women with low bone mass to see if the addition of green tea flavanols , Tai Chi exercise or both green tea plus Tai Chi could help improve markers for bone health and muscle strength in study participants. At the end of the six-month clinical trial they found that 500 mg green tea extract (equivalent to 4-6 cups of green tea daily), alone or in combination with Tai Chi, improved markers for bone formation, reduced markers of inflammation and increased muscle strength in study participants.

Tea May Improve Mental Sharpness

Consuming black tea improved attention and self-reported alertness in a human study conducted by Unilever R&D, Vlaardingen, The Netherlands.  In this placebo-controlled study, designed to measure attention, task performance and alertness, subjects drinking tea were more accurate on an attention task and also felt more alert than subjects drinking a placebo. This work supports earlier studies on the mental benefits of tea.  In addition, two other studies provide a broader perspective on tea’s effects on psychological well-being, showing benefits for tiredness and self-reported work performance, as well as mood and creative problem solving. These studies provide support for tea’s benefits for mental sharpness, as measured by attention, mood and performance.

Bioactive Compounds in Tea

Tea is one of the most thoroughly researched for its potential health benefits. The leaves of the Camellia sinensis plant contain thousands of bioactive compounds that have been identified, quantified and studied for their mechanisms of action. While many of these compounds act as antioxidant flavonoids, not all of tea’s benefits are thought to be solely from antioxidant activity.

For example, new research presented by Alan Crozier, PhD, of the University of Glasgow, UK, revealed that while many tea flavonoids in green and black tea are digested and absorbed, others are more resistant to digestion and travel mostly intact to the lower gastrointestinal tract, where they provide a probiotic effect by enabling beneficial bacteria to thrive.

Tea Provides Profound Health Benefits

The latest data provide further evidence of tea’s potential role in promoting good health, perhaps due to the fact that tea flavonoids are the major contributors of total flavonoid intake in the U.S. diet:

  • Tea drinking may play a role in helping to prevent cells from becoming cancerous;
  • Tea may play a role in enhancing the effect of chemotherapy drugs used for treating certain cancers; and
  • Flavonoids in tea, among other compounds present in tea leaves, may help ward off inflammation and vascular damage linked to chronic conditions associated with aging.

“As the second most consumed beverage in the world next to water, tea accounts for a significant amount of the flavanol intake worldwide,” states Joe Simrany, President, Tea Council of the USA, which has been spear-heading this International Tea & Human Health Symposium since 1991. “This gathering of renowned global nutrition scientists is the world’s leading platform to release new research on tea, and acts as a catalyst for continuing research on tea in areas as diverse and novel as cognitive function, bone growth, weight management, cancer and vascular function.”

Complete studies and abstracts are posted to the Tea Association of Canada website at www.tea.ca

The symposium was sponsored by American Cancer Society, American Institute for Cancer Research, American Society for Nutrition, American College of Nutrition, The Linus Pauling Institute, American Medical Women’s Association, Food and Agriculture Organization of the United Nations and the Tea Council of the USA

2013 UPDATE:  NEW STUDIES SHOW NUMBEROUS HEALTH BENEFITS OF TEA

The December 2013 issue of The American Journal of Clinical Nutrition, features 12 new articles about the many health benefits of tea. Each paper is based on presentations from world-renowned scientists who participated in the Fifth International Scientific Symposium on Tea and Human Health, held at USDA in September 2012 (see article above).   Twelve internationally renowned researchers contributed to the AJCN supplement, including experts from USDA, National Institutes of Health, UCLA, University of Glasgow and University of L’Aquila, among others. “The scientists who contributed their original research and insights are among the best in the world, and together, this body of research has significantly advanced the science of tea and human health,” said compendium editor Jeffrey Blumberg, PhD, Professor, Friedman School of Nutrition Science and Policy and Director, Antioxidants Research Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston.  “These new peer-reviewed papers add to the previously-published body of evidence that shows that tea can improve human health—both physically and psychologically,” added Blumberg. “Humans have been drinking tea for some 5,000 years, dating back to the Paleolithic period. Modern research is providing the proof that there are real health benefits to gain from enjoying this ancient beverage.”

 

 

DISCLAIMER:  Serenity Tea Sips™ has provided this material as a source of information only. It is not intended to substitute for the medical expertise and advice of your primary health care provider.  We encourage you to discuss any decisions about treatment or care with your health care provider.