Pedro is a Technology consultant, former CIO, former DoD & DARPA contractor, natural alternative medicine and ancient history researcher, former U.S. Army paratrooper, active seeker of the truth in Jesus the Christ.

“You’re either part of the solution or you’re part of the problem.”

 

The Power of Green Tea

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Working the tea farm

Photo: Man working the tea farm

Whether you’re looking into detox, diet or simply enjoy the flavors of green tea, there is no doubt that you have heard about the multiple benefits of this ancient plant. I share with you some of my findings.

Origins and Historical use
Folk Medicine
Culinary uses
Health benefits
Research
Negative effects / allergies
References

Origins and Historical use

With its earliest reference dating back to the year 2737 BC, green tea history is long and fascinating. Green Tea comes from the shrub Camellia Sinensis, whose leaves and leaf buds are harvested and dried to make the tea. This shrub is native to Southeast Asia, but is now grown across the world. Green tea’s roots lie with the Chinese Emperor Shennong, who accidentally drank water that had a dead tea leaf boiled in it. Green tea history has it’s origin linked to the highest tier of Chinese society, which made it expensive and inaccessible to less-wealthy people. It was not until the fourteenth century that green tea became widespread throughout China for people from all walks of life who enjoyed for its taste and medicinal qualities.

Green tea was brought to Japan from China. Although it is now one of the most popular beverages in Japan, it was once so precious that only a select few, such as monks and nobility could afford its pleasures. Thanks to the efforts of Eisai, a twelfth century Zen monk, green tea was introduced to the public, and samurai warriors and common people began to enjoy the new drink. Green Tea is most popular in Asia, where it acts both as a general tonic and a social drink. It is also drunk in large quantities in the Middle East and Morocco.

While green tea has been enjoyed in China for around 5000 years, its history in the west is relatively short in comparison. One of the most interesting aspects of green tea history is its slow move from Asia to Europe and America. European traders were first introduced to tea in the 16th century during trips to East Asia. The new drink so pleased the sailors and their homelands that it became an important commodity. Even now, Great Britain’s national beverage is tea, though most British tea drinkers prefer black teas. Along with settlers, tea was shipped over to the Americas, where it enjoyed great popularity among the early colonists. In fact, tea was so popular in America that Great Britain imposed a Tea Tax in 1767 that infuriated the colonists and sparked the Boston Tea Party of 1773, where 45 tons of green tea was dumped into the harbour.

Folk Medicine

Green Tea is one of those herbal remedies whose benefits are so numerous that they are hard to even list. It has been used as a traditional medicine for more than 4,000 years in Indian and Chinese culture, and is even more popular today. Green tea has been consumed throughout the ages in India, China, Japan, and Thailand. In traditional Chinese and Indian medicine, practitioners used green tea as a stimulant, diuretic (to promote the excretion of urine), astringent (to control bleeding and help heal wounds), and to improve heart health. Other traditional uses of green tea include treating flatulence (gas), regulating body temperature and blood sugar, regulating cholesterol, promoting digestion, improving sight, and improving mental processes. According to Chinese folk medicine, sleeping on tea leaves helps reduces blood pressure, relieves insomnia and soothes headache.

Duke and Wain (1981) report1 that green tea has a folk reputation as analgesic, antidotal, astringent, cardiotonic, carminative, CNS-stimulant, demulcent, deobstruent, digestive, diuretic, expectorant, lactagogue, narcotic, nervine, refrigerant, stimulant, and stomachic; used for bruises, burns, cancer, cold, dogbite, dropsy, dysentery, epilepsy, eruptions, fever, headache, hemoptysis, hemorrhage, malaria, ophthalmia, smallpox, sores, toxemia, tumors, and wounds.

Chinese people have long known of the health benefits of green tea and used it medicinally. When China had the power of the sea, the seamen were given the necessary amount of green tea. The antioxidants in the green tea they drank fought off scurvy. While there are numerous Chinese green tea benefits, traditionally there are also many green tea uses, not just as a healthy beverage, but as a skin wash, a mouthwash, and as a main ingredient in tea folk remedies. No wonder, when Eisai was introducing the effect of drinking green tea to Japanese, he professed, “A medicine is for one disease only, but green tea is a kind of panacea that can prevent and treat all sorts of ailments”.

Culinary uses

Green tea is not only popular as a beverage (both hold and cold), but is also used in various other drinks and foods. Green Tea Liquor, Green Tea Frappucino, Green Tea ice-cream etc are becoming increasing popular. Green tea also adds a subtle flavour to dishes.

Green tea is often used as a spice while stir-frying. Cooking rice with green tea makes a lovely dish. It is also used in desserts – teas that are lemon, fruit, jasmine or rose can be used in cakes, cookies, ice cream, pudding, smoothies and shakes. Tea leaves are sometimes used as salad toppings, and brewed tea in salad dressings.

Health benefits

Green tea is generally considered to be the healthiest type of tea because it is unfermented. Hence it retains more of its antioxidants and thus offers more health benefits. Green tea is particularly rich in health-promoting flavonoids (which account for 30% of the dry weight of a leaf), including catechins and their derivatives. Green tea contains a variety of chemical compounds, minerals, vitamins, volatile oils and essential nutrients, but the primary compounds that are believed to provide green tea with its health and medicinal effects are polyphenols, particulary the antioxidant epigallocatechin gallate (EGCG). Researchers have found that only 10 lbs of green tea will significantly increase the body’s antioxidant capacity for at least 2 hours.

Some of green tea’s most important health benefits include protection against cardiovascular diseases, protection against cancer, increased bone density (protection against osteoporosis20, arthritis), promotion of fat loss (with its combination of antioxidants and caffeine, green tea has a unique ability to help its drinkers lose fat by inhibiting the enzyme2 that turns fatty acids into fat cells), and protection against neurodegenerative diseases. One of the most important benefits of green tea is its antioxidants’ ability to remove iron from the blood and protect certain brain cells necessary for memory retention and spatial cognition. Studies have shown that green tea can decrease its drinkers’ risk for Parkinson’s, Alzheimer’s19 and dementia.

Other benefits of green tea comes from it’s  antibiotic effects, anti-diabetes8 effects, antidepressant properties, anti-venom effects. It is known to increase metabolic rate, boost mental alertness, boost immune system, lower chances of cognitive impairment, lower stress hormone levels15, and help with rheumatoid arthritis9, anogenital warts10, bacterial and fungal infections, bad breath, inflammatory bowel disease (IBD), iron overload disorders, weight loss and cholesterol  etc.

Green Tea Extract: Green Tea Extract is the concentrate of the green tea leaf, and has all the essential properties of the green tea leaf. To make green tea extract, the catechins (most often EGCG) are isolated and drawn out, using water or steam, then condensed before spray drying. The resulting powder can be put into a tablet or capsule or made into a liquid.

Green tea extract contains many times more catechins than could be found in a cup of green tea and is swallowed in pill form or added to a drink. Just as in green tea, the extract is loaded with plant nutrients called phytochemicals. Not only does the extract provide anti-oxidants, but studies have shown that our blood’s capacity for holding anti-oxidants increases. Not only do we get the healthy nutrients in the extract, but also our bodies are able to hold more.

Research

The health benefits of green tea have been extensively researched and, as the scientific community’s awareness of its potential benefits has increased, so have the number of new studies. Green tea has been extensively studied in people, animals, and laboratory experiments.

Anti-cancer effect: In the last ten years, green tea’s cancer-preventive effects have been widely supported by epidemiological, cell culture, animal and clinical studies. For cancer prevention, the evidence is so overwhelming that the Chemoprevention Branch of the National Cancer Institute has initiated a plan for developing tea compounds as cancer-chemopreventive agents in human trials. Emerging clinical studies suggest that the polyphenols in tea, especially green tea, may play an important role in the prevention of cancer. Laboratory cell culture studies show that green tea polyphenols are powerful triggers of apoptosis12 (cell suicide) and cell cycle arrest in cancerous but not in normal cells. (Cell cycling is the process cells go through to divide and replicate).

These anticancer actions have been assumed to be due to the powerful antioxidant effects of green tea’s catechins, especially EGCG. This is a reasonable assumption, given that a number of studies have shown that green tea possesses remarkable antioxidant properties. In one study published in the November 2004 issue of Mutation Research, EGCG’s protective antioxidant effects against several carcinogens were found to be 120% stronger than those of vitamin C.

But while green tea’s antioxidant prowess is impressive, recent studies show it is far from the only way in which this multi-talented beverage protects against cancer. One of these mechanisms is green tea’s ability to inhibit angiogenesis, the development of new blood vessels. Cancer cells, which are constantly attempting to divide and spread, have an endless appetite that can only be temporarily quieted by increasing the number of blood vessels that supply them with nutrients. By inhibiting angiogenesis, green tea helps starve cancer. Several researches have been carried out to evaluate green tea’s effectiveness against breast cancer11, prostate cancer3, ovarian cancer7, skin cancer13, colorectal cancer18, biliary tract cancer, lung cancer, stomach cancer14, and gastrointestinal cancer4.

Heart Health and Cardiovascular diseases: An elevation in the amount of free radicals in the arteries is a key event in many forms of cardiovascular disease. The latest research shows that green tea catechins inhibit the enzymes involved in the production of free radicals in the endothelial lining16 of the arteries. Green tea has been shown to effectively lower risk of atherosclerosis5,6 by lowering LDL cholesterol, triglycerides, lipid peroxides (free radicals that damage LDL cholesterol and other lipids or fats) and fibrinogen (a protein in the blood involved in the formation of blood clots), while improving the ratio of LDL to HDL cholesterol. In animal studies in which green tea was given in human equivalent doses to hamsters, atherosclerosis was inhibited 26-46% in those receiving the lower dose (equivalent in humans to 3-4 cups per day), and 48-63% in those receiving the higher dose (10 cups a day in humans). In Japanese studies, green tea consumption has been found to be an independent predictor for risk of coronary artery disease.21 In one study, those drinking 5 or more cups of green tea each day were found to be 16% less likely to suffer from coronary artery disease.

Green tea catechins help thin the blood and prevent the formation of blood clots by preventing the formation of pro-inflammatory compounds derived from omega-6 fatty acids. The primary catechin in green tea, EGCG confers such powerful protection that it can help prevent the death of heart muscle cells following ischemia/reperfusion injury. EGCG prevents heart muscle damage by blocking the activation of inflammation-related compounds (including NF-kappa-B and STAT-1) that play a critical role in promoting the oxidative damage that kills heart cells in reperfusion injury. Researchers believe EGCG can be used to help minimize damage in patients with acute coronary artery disease.

Hypertension:17 A study published in the July 2004 issue of the Archives of Internal Medicine found that among persons consuming tea regularly for at least one year, the risk of developing high blood pressure was 46% lower among those who drank ½ cup to 2 ½ cups per day, and 65% less among those consuming more than 2 ½ cups per day. In another study, this one of rats bred not only have high blood pressure but also to be prone to strokes, those rats given green tea had significantly lower systolic and diastolic blood pressure compared to controls, who received plain water.

Negative effects / allergies

Green tea is likely safe for most people. Most of the side effects of green tea are the results of its caffeine content. People who drink excessive amounts of green tea for prolonged periods of time may experience irritability, insomnia, heart palpitations, and dizziness. Caffeine overdose can cause nausea, vomiting, diarrhea, headaches, and loss of appetite.

Possible interactions: If you are being treated with any of the following medications, you should not drink green tea or take green tea extract without first talking to your health care provider.

Adenosine: Green tea may inhibit the actions of adenosine, a medication given in the hospital for an irregular (and usually unstable) heart rhythm. Beta-blockers, Propranolol, and Metoprolol: Caffeine may increase blood pressure in people taking propranolol and metoprolol (medications used to treat high blood pressure and heart disease). Benzodiazepines: Caffeine has been shown to reduce the sedative effects of benzodiazepines (medications commonly used to treat anxiety, such as diazepam and lorazepam). Blood Thinning Medications (Including Aspirin): People who take warfarin, a blood thinning medication, should not drink green tea. You should not mix green tea and aspirin because they both prevent platelets from clotting. Using the two together may increase your risk of bleeding. Clozapine: The antipsychotic effects of the medication clozapine may be reduced if taken fewer than 40 minutes after drinking green tea. Ephedrine: When taken together with ephedrine, green tea may cause agitation, tremors, insomnia, and weight loss. Lithium: Green tea has been shown to reduce blood levels of lithium (a medication used to treat manic/depression). Chemotherapy: There have been reports of both green and black tea extracts stimulating a gene in prostate cancer cells that may cause them to be less sensitive to chemotherapy drugs. Monoamine Oxidase Inhibitors (MAOIs): Green tea may cause a severe increase in blood pressure (called a “hypertensive crisis”) when taken together with MAOIs, which are used to treat depression. Examples of MAOIs include phenelzine and tranylcypromine. Oral Contraceptives: Oral contraceptives can prolong the amount of time caffeine stays in the body and may increase its stimulating effects. Phenylpropanolamine: A combination of caffeine and phenylpropanolamine (an ingredient used in many over-the-counter cough and cold medications and weight loss products) can cause mania and a severe increase in blood pressure. The FDA issued a public health advisory in November 2000 to warn people of the risk of bleeding in the brain from use of this medication and has strongly urged all manufacturers of this drug to remove it from the market.

Special precautions and warnings: People with heart problems, kidney disorders, stomach ulcers, and psychological disorders (particularly anxiety) should not take green tea. Pregnant and breastfeeding women should also avoid green tea.


References

 

  1. Medicinal plants of the world. By J.A. Duke and K.K Wain. 1981. Computer index with more than 85,000 entries. 3 vols.
  2. Boschmann M, Thielecke F. The effects of epigallocatechin-3-gallate on thermogenesis and fat oxidation in obese men: a pilot study. J Am Coll Nutr. 2007;26(4):389S-395S.
  3. Bettuzzi S, Brausi M, et. al. Chemoprevention of human prostate cancer by oral administration of green tea catechins in volunteers with high-grade prostate intraepithelial neoplasia: a preliminary report from a one-year proof-of-principle study. Cancer Res. 2006;66(2):1234-40.
  4. Borrelli F, Capasso R, Russo A, Ernst E. Systematic review: green tea and gastrointestinal cancer risk. Aliment Pharmacol Ther Mar 1, 2004;19(5):497-510.
  5. Miura Y, Chiba T, Tomita I, et al. Tea catechins prevent the development of atherosclerosis in apoprotein E-deficient mice. J Nutr. 2001;131(1):27-32.
  6. Steptoe A, Gibson EL, Vuonovirta R, Hamer M, Wardle J, Rycroft JA, Martin JF, Erusalimsky JD. The effects of chronic tea intake on platelet activation and inflammation: a double-blind placebo controlled trial. Atherosclerosis. 2007;193(2):277-82.
  7. Zhang M, Lee AH, Binns CW, Xie X. Green tea consumption enhances survival of epithelial ovarian cancer. Int J Cancer Nov 10, 2004;112(3):465-469.
  8. Ryu OH, Lee J, Lee KW, et al. Effects of green tea consumption on inflammation, insulin resistance and pulse wave velocity in type 2 diabetes patients. Diabetes Res Clin Pract. 2006;71(3):356-8.
  9. Kim HR, Rajaiah R, Wu QL, Satpute SR, Tan MT, Simon JE, Berman BM, Moudgil KD. Green tea protects rats against autoimmune arthritis by modulating disease-related immune events. J Nutr. 2008 Nov;138(11):2111-6
  10. Gross G, Meyer KG, Pres H, Thielert C, Tawfik H, Mescheder A. A randomized, double-blind, four-arm parallel-group, placebo-controlled Phase II/III study to investigate the clinical efficacy of two galenic formulations of Polyphenon(R) E in the treatment of external genital warts. J Eur Acad DermatolVenereol. 2007;21(10):1404-12.
  11. Pianetti S, Guo S, Kavanagh KT, Sonenshein GE. Green tea polyphenol epigallocatechin-3 gallate inhibits Her-2/neu signaling, proliferation, and transformed phenotype of breast cancer cells. Cancer Res. 2002;62(3):652-655.
  12. Fassina G, Vene R, Morini M, et al. Mechanisms of inhibition of tumor angiogenesis and vascular tumor growth by epigallocatechin-3-gallate. Clin Cancer Res, 2004;10(14):4865-73.
  13. Nihal M, Ahmad N, Mukhtar H, Wood GS. Anti-proliferative and proapoptotic effects of (-)-epigallocatchin-3-gallate on human melanoma: possible implications for the chemoprevention of melanoma. International Journal of Cancer 2005;114(4):513-21.
  14. Setiawan VW, Zhang ZF, Yu GP, et al. Protective effect of green tea on the risks of chronic gastritis and stomach cancer. Int J Cancer. 2001;92(4):600-604.
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  16. Ying CJ, Sun XF, Zhang SL, Zhang XP, Mao LM, Zuo XZ, Yao P. ROS-related enzyme expressions in endothelial cells regulated by tea polyphenols. Biomed Environ Sci. 2004 Mar;17(1):33-9. 2004.
  17. Yang YC, Lu FH, Wu JS, Wu CH, Chang CJ. The protective effect of habitual tea consumption on hypertension. Arch Intern Med. 2004 Jul 26;164(14):1534-40. 2004.
  18. Yang G, Shu XO, Li H, Chow WH, Ji BT, Zhang X, Gao YT, Zheng W. Prospective cohort study of green tea consumption and colorectal cancer risk in women. Cancer Epidemiol Biomarkers Prev. 2007 Jun;16(6):1219-23. 2007.
  19. Weinreb O, Mandel S, Amit T, Youdim MB. Neurological mechanisms of green tea polyphenols in Alzheimer’s and Parkinson’s diseases. J Nutr Biochem. 2004 Sep;15(9):506-16. 2004.
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  21. Sano J, Inami S, Seimiya K, Ohba T, Sakai S, Takano T, Mizuno K. Effects of green tea intake on the development of coronary artery disease. Circ J. 2004 Jul;68(7):665-70. 2004.