If you drink green tea for your health, be aware that the catechin and caffeine levels can vary by more than 240% across products, and some green tea brands have significant amounts of lead in their tea leaves, but the lead doesn't leach out from the tea bag into your tea drink.
Decaffeinated green tea doesn't have any measurable levels of lead in it. Recent tests by ConsumerLab.com, reporting on the quality of health and nutrition products reviewed several brands of green tea such as Bigelow, Celestial Seasonings, Lipton, Salada, and Teavana. Findings revealed that some tea leaves did contain significant amounts of lead. The forms of green tea products reviewed were tea bags, a loose tea, and a K-Cup (for brewing in a Keurig machine).
You can check out the reviews of green tea brands if you join as a member of the ConsumerLab.com site. Also, you can read various studies of large populations which found that drinking at least 2 to 3 cups of green tea daily is associated with a reduced risk of cardiovascular disease, certain cancers, and type 2 diabetes. For example, see the December 1, 2013 Medical News Today article, "What are the health benefits of green tea?"
Supplements containing green tea compounds may assist in weight loss and reduce the risk of prostate cancer
ConsumerLab,com found the amount of tea leaf in a suggested serving of each product to range from 1.38 grams to 3.14 grams, with some larger tea bags actually containing less tea than some smaller bags. In terms of chemical strength, servings yielded from 25 mg to 86 mg of EGCG. You also may be interested in taking a look at other warnings and/or recalls on the ConsumerLab.com site.
If you want to learn more about EGCG, it's one of several key "catechin" compounds in green tea and a natural phenol in the flavanol family. You also can check out articles on green tea catechins such as "Other Healthy Beverage Options - Harvard School of Public Health" and "Green tea catechins and cardiovascular health: an update."
Very little caffeine levels in numerous decaffeinated green tea bags
Numerous decaffeinated green teas contain just 5 mg, according to the ConsumerLab.com reports. With caffeinated green teas, the ConsumerLab.com review noted that the amount of caffeine per serving ranged from 22.7 mg (less than in a can of cola) to 85.8 mg (similar to that in a cup of regular coffee).
So if you're sensitive to caffeine, there are the decaf varieties. If you look at the independent brands, even the decaf varieties can vary in caffeine levels.
Decaf green tea supplements
With the decaf green tea supplements, some have as little as only 3 mg of caffeine per capsule of green tea extract. You also can take a look at the site, "Mega Green Tea Extract (decaffeinated), 100 - Life Extension." Although, this brand wasn't listed upfront on the news page for nonmembers of the Consumer.Lab site as being tested as a green tea supplement on the Consumer.Lab report, according to the manufacturer's label on the container of the green tea supplement, there's very little caffeine in the decaf supplements, if you choose a supplement that says it's decaffeinated green tea. One capsule of Life Extension’s Mega Green Tea Extract provides more polyphenols than you get from drinking three cups of green tea, notes the company's website for the product.
This 98% green tea extract is standardized to provide high potency EGCG, by far the most important polyphenol green tea provides. And green tea powdered extracts have been shown to absorb 60%-90% better into the bloodstream338 and to be far more bioavailable than drinking green tea itself.
Mega Green Tea Extract has been concentrated and dual standardized to ensure the highest quality, consistency and biological activity. This advanced extract contains 98% total polyphenols and 45% epigallocatechin-3-gallate (EGCG). You can check out the medical and scientific journal articles and studies at the Life Extension Supplements References site on green tea and its effects on health.
Cost of green tea from bottled to tea bags and supplements
ConsumerLab.com also noted that the cost in order to extract 200 mg of EGCG from the brewed teas ranged from 27 cents to $2.50. The cost to obtain the same amount of EGCG from green tea dietary supplements tested earlier by ConsumerLab.com ranged from 10 cents to $3.41, and from bottled green teas the cost was $4.45 to $71,72. So you can see which form of green tea is cheaper -- the brewed tea rather than the expensive bottled green tea.
The less work that has to be done on the green tea, the cheaper it is. It costs a manufacturer a lot more to bottle green tea than to put green tea in tea bags. The less work the manufacturer does on the tea and the more work you have to do such as brew the tea, the less it's going to cost you to enjoy a cup of green tea or decaf green tea.
Lead found was in the tea leaves, not in the brewed tea: Japanese green tea leaves had no measurable levels of lead in the tea
ConsumerLab,com also measured the amount of lead, a toxic heavy metal, in each product. Lead is known to be taken up into tea leaves from the environment. The lead gets into the tea plants grown near industrial areas. Much of the green tea comes from specific areas of China and is imported.
You also have Japanese green tea, and the Japanese variety of green tea didn't have measurable lead in the tea leaves. See, "Fresh Japanese Green Tea - Den's Tea - Japanese Tea Specialist." Brewed green tea didn't have measurable levels of lead leaching out into the water you drink. So don't eat the green tea leaves or grind them into powder to use in ice creams or other types of food or desserts.
ConsumerLab.com found that some brands of green tea imported from China had measurable lead in the leaves, but the lead didn't leach out into the brewed tea. So the report advised people not to eat the tea leaves. On the other hand, Japanese green tea leaves didn't have measurable levels of lead, according to the report.
Since the lead comes from the soil and is not something done in a factory to the tea, and since most of the lead stays in the leaves and doesn't leach out into the tea, using a tea bag or other type of filter helps. Just choose brands of tea with the least amount of measurable lead. You can read the green tea report online if you become a member of ConsumerLab.com and check out the site on green tea reviews, "Brewable Teas Review."
Green tea supplements study
Green tea supplements may lower the risk of certain types of cancer, shrink uterine fibroids, and aid in weight control, and drinking green tea has been associated with a lower risk of cardiovascular disease, diabetes, as well as a lower risk of some cancers, according to a new study discussed in a November 6, 2013 news release, "New research shows tea may help promote weight loss, improve heart health and slow progression of prostate cancer."
On another note, during the Dr. Oz Show (November 27, 2013), ConsumerLab.com president Dr. Tod Cooperman talked with Dr. Oz about adulterated herbal supplements, as well as supplements to help prevent or treat colds and flu tested by ConsumerLab.com (echinacea, zinc, vitamin D). Read Dr. Cooperman's article "3 Top Supplements for Colds and Flu" on Dr. Oz's site and watch the segment "What's Really in Your Herbal Supplements?"
Decades worth of research shows that tea—the second most consumed beverage in the world—may help prevent chronic illnesses, including heart disease, certain types of cancer and type 2 diabetes. New research shows tea has been found to help promote weight loss and maintain a healthy weight, improve bone health and activate areas of the brain that bolster attention, problem solving and mood.
The December 2013 issue of the American Journal of Clinical Nutrition features 12 new articles about the relationship between tea and human health. 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.
Highlights of some of the compelling reports published through the AJCN include the following five papers:
Tea Leaf Polyphenols May Promote Weight Loss
Tea polyphenols and the caffeine content in tea increase energy expenditure and fat oxidation, providing benefits for achieving and maintaining an ideal body weight. The results of one meta-analysis suggests the increase in caloric expenditure is equal to about 100 calories over a 24-hour period, or 0.13 calories per mg catechins.
In a related review, researchers concluded that subjects consuming green tea and caffeine lost an average of 2.9 pounds within 12 weeks while adhering to their regular diet. Population-based studies also show that habitual tea drinkers have lower Body Mass Indexes (BMIs) and waist-to-hip ratios and less body fat than non-tea drinkers. In addition, green tea and caffeine also appear to boost fat oxidation over 24 hours by an average of 16% or 0.02 grams per mg catechins.
Tea May Reduce Risk for Some Cancers
Green tea polyphenols may play a role in arresting the progression of certain cancers. For example, in a double-blind, placebo-controlled study, supplementation with 600 mg/d green tea catechins reduced the progression of prostate cancer. The researchers reported that after a year, 9% of men in the green tea supplemented group had progressed to prostate cancer whereas 30% of men in the placebo group had progressed.
Hundreds—if not thousands—of laboratory, epidemiological and human intervention studies have found anti-cancer properties in compounds present in tea. The types of cancer that have shown benefits of tea include cancers of the gastrointestinal tract, lung, prostate, breast, and skin. The proposed mechanisms of action for providing protection against cancer include antioxidant effects, inhibition of growth factor signaling, as well as improving the efficacy of chemotherapy agents.
Tea Catechins are Cardioprotective
Numerous studies suggest 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, published in the AJCN provides further support. Study results published by Claudio Ferri, MD, University L'Aquila, Italy, found that black tea reduced blood pressure, and among hypertensive subjects, it helped 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 0.45 grams fat/lb. body weight.
The results suggest that tea prevented the reduction in flow-mediated dilation (FMD), the ability to increase arterial 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.
"Our studies build on previous work to clearly show that drinking as little as one cup of tea per day supports healthy arterial function and blood pressure. These results suggest that on a population scale, drinking tea could help reduce significantly the incidence of stroke, heart attack and other cardiovascular diseases," concluded Dr. Ferri, according to the November 6, 2013 news release, "New research shows tea may help promote weight loss, improve heart health and slow progression of prostate cancer."
Tea Flavonoids Improve Bone Strength and Quality
Osteoporosis is a major public health concern but new research suggests that polyphenols in green tea may help improve bone quality and strength through many proposed mechanisms. In fact, one study found that tea drinking was associated with a 30% reduced risk in hip fractures among men and women over 50 years old.
In a study of 150 postmenopausal women, researchers reported 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. Numerous other studies have found that green tea flavanols provide a restorative effect to bone remodeling to help maintain bone density and slow bone loss.
Tea Improves Mood, Alertness and Problem Solving
Results from new research published in the American Journal of Clinical Nutrition found that drinking tea improved attention and allowed individuals to be more focused on the task at hand. In this placebo-controlled study, subjects who drank tea produced more accurate results during an attention task and also felt more alert than subjects drinking a placebo.
These effects were found for 2-3 cups of tea consumed within a time period of up to 90 minutes. Several studies have evaluated the role of tea in strengthening attention, mood and performance, and the results have been promising. It is thought that the amino acid theanine and caffeine, both present in tea, contribute to many of tea's psychological benefits.
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, according to the November 6, 2013 news release, New research shows tea may help promote weight loss, improve heart health and slow progression of prostate cancer.
"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 in the news release. "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." Also check out the abstract of a study, "Cancer prevention by green tea: evidence from epidemiologic studies."
AJCN published 12 new articles on the relationship between tea and human health including:
- Tea consumption and cardiovascular disease risk
- Human studies on the absorption, distribution, metabolism, and excretion of tea polyphenols
- Tea, flavonoids, and cardiovascular health: endothelial protection
- Acute effects of tea consumption on attention and mood
- Cancer prevention by green tea: evidence from epidemiologic studies
- Catechin- and caffeine-rich teas for control of body weight in humans
- Tea and flavonoids: where we are, where to go next
- Cellular targets for the beneficial actions of tea polyphenols
- Does tea prevent cancer? Evidence from laboratory and human intervention studies
- Tea and bone health: steps forward in translational nutrition
- Interactions of black tea polyphenols with human gut microbiota: implications for gut and cardiovascular health
The Tea Council of the USA is a non-profit association that was formed in 1950 as a joint partnership between tea packers, importers and allied industries within the United States, and the major tea producing countries. It functions as the educational arm of the tea industry with a primary goal of increasing overall awareness of tea by providing information about its many positive attributes.
One of the Council's primary objectives is the dissemination of key scientific findings about tea to the public. The Tea Council does this in several ways including: funding scientific meetings to bring tea researchers from around the world together to share key information and identify next steps for future research projects; and working with health organizations and international scientists to disseminate information about potential positive health effects of tea consumption on a public level.
Green tea supplements, brewable teas, and bottled drinks reviewed in the ConsumerLab.com report
Andrew Lessman's Green Tea EGCG-200Arizona Green Tea -- Ginseng & HoneyBigelow Green TeaBigelow Green Tea-Certified 100% OrganicBigelow Green Tea-Naturally DecaffeinatedCelestial Seasonings Green Tea (K-Cup)Diet Snapple Green TeaEnzymatic Therapy Green Tea Elite with EGCGHarney & Sons Organic GreenHealthy Origins TeavigoHonest Tea Green Tea with HoneyLife Extension Mega Green Tea ExtractLipton Green TeaNature's Bounty Green Tea ExtractNew Chapter Green & White Tea ForceNOW EGCg Green Tea ExtractOmega Sports Green TeaPuritan's Pride Green TeaSalada Green Tea Naturally DecaffeinatedSolgar Green Tea Leaf ExtractSwanson Superior Herbs Green Tea ExtractTeavana Green Tea Gyokuro ImperialTrunature (Costco) Green TeaVitamin Shoppe Green Tea ExtractVitamin World Green TeaGaia Herbs Green Tea