|
Green Tea's Healing Properties
By David Caruso-Radin, LAc, MS, MQP, Dipl. ABT
David is a friend of Teance and practitioner of Traditional Chinese Medicine. In this article he addresses the medicinal value of tea from both Chinese and Western medicinal perspectives:
After water, tea is the most commonly enjoyed beverage in the world. It is defined as any beverage made from the Camellia Sinesis plant (beverages made from other plants- peppermint, chamomile, rooibos, etc.- are classified as tisanes). Considering tea's wonderful healing effects it's easy to see why it is so popular:
"Born to this earth are three kinds of creatures. Some are winged and fly. Some are furred and run. Still others stretch their mouths and talk. All of them must eat and drink to survive. There are times, nonetheless, when the meaning of the word 'drink' becomes obscure. If one would merely slake his thirst, then he can drink rice and water. Should melancholy, sadness or anger strike, he can turn to wine to drink. But if one would dispel an evening's unproductive lassitude, the meaning of 'drink' is tea." 1
- Lu Yu from "The Classic of Tea"
The History of Tea
There are many stories of how tea might have been discovered. There is the tale of the famous Chinese emperor Shen Nong, who, while boiling some water, saw a gust of wind blow a handful of leaves from the nearby trees into his pot. He tasted the strange new brew and was overjoyed at what he found, thus, tea was invented. In yet another story, the Buddhist monk Bodhidharma fell asleep while meditating. So as not to fall asleep again, he cut off his eyelids. Where his eyelids fell two tea plants arose.2
Archaeological evidence suggests that tea may have been brewed as many as 500,000 years ago. The first recorded monograph of the medicinal properties of tea comes from Lu Yu in his book The Classic of Tea, 780 A.D. Tea arrived in Japan in the early ninth century. The first Japanese text on tea, Kissa Yojoki (How to Stay Healthy by Drinking Tea), was written in the early thirteenth century by a Zen priest, Eisai. The text begins with the following sentence, "Tea is the ultimate mental and medical remedy, and has the ability to make one's life more full and complete." 3
Green Tea Classification
Green tea is made from the leaves of the Camellia Sinensis plant. The difference between Green, Wu Long (or Oolong as it is commonly spelled), and Red (what we call Black in the West) teas is the amount that the leaves are oxidized. Green tea leaves are not significantly oxidized; between 0-20%. To prevent oxidation, the leaves are heated, either with steam (more common in Japan) or dry heat (more common in China). All teas made from the Camellia Sinensis leaf have the same amount of caffeine. It is the oxidation process that makes the caffeine more usable by the body, and since green teas are not highly oxidized the usable amount of caffeine in green tea is lower than in Wu Long or Black/Red teas.
Green Tea from a Chinese Medicine Perspective
According to Chinese medicine, green tea enters the stomach channel and is bitter and cold. Thus, it has a special effect on the stomach and can be used for disorders that are hot in nature (especially when the disorder involves heat in the stomach). The bitter nature of green tea gives it a purgative or sedating effect. In general, bitter herbs purge heat and dampness. In the case of green tea, the action occurs most specifically with the stomach and gastrointestinal tract, draining heat, dampness and rebellious qi downward. For example, with acid reflux, green tea may help to quell the fire and soothe the upward flowing of qi.
Actions of Green Tea
- Harmonizes the stomach, directs rebellious stomach qi downward, and relieves diarrhea. Stomach qi, by nature, needs to descend. In dysfunction it may rebel and rise, causing nausea, vomiting, belching, and acid reflux. Stagnation or heat might cause stomach qi to rise. Dysfunctions of the gastrointestinal tract (esp. nausea and vomiting) may improve with the use of green tea. [Note: It is important to understand that, from a Chinese medicine perspective, disharmonies may have many causes and green tea is useful for stomach disharmonies caused by dampness and/or heat.] 4
- Dispels dampness. In Chinese medicine, excess fat is a form of excess dampness. Green tea is useful in obesity, because it helps to purge out excess fat. It is also useful for purging excess dampness from the intestines (esp. for diarrhea) through its diuretic nature.5
- Clears the head. It can help to relieve headaches and improve concentration through its stimulating effect.6
Green Tea from a Western Medicine Perspective
From the perspective of Western Medicine, the healing properties of herbs are related to their constituent parts, known as phytochemicals. The phytochemicals of green tea include: caffeine, theophylline, theobromine, tannins, and antioxidants (catechins [especially EGCG] and flavonoids [especially quercitin]). Antioxidants are substances that neutralize free radicals (damaging compounds in the body that have been linked to aging).7
- Stimulants (caffeine, theophylline, and theobromine) create a stimulating and antidepressive effect, improve digestion, and offer anti-inflammatory benefits.8 Tea drinkers who want to limit the effects of caffeine should simply pour off the first steeping, which contains as much as 80% of the caffeine. The remaining infusions will have far less caffeine, but will still retain much of the flavor and the anti-oxidants.
- L-Theanine9 is an amino acid commonly found in the camellia Sinensis plant and in few other plants. L-Theanine is one of very few phytochemicals that can cross the blood-brain barrier. As a consequence it can enter the brain and increase the level of the neurotransmitters: serotonin, dopamine, and GABA. L-Theanine has been shown to reduce mental and physical stress, and may produce feelings of relaxation and improve cognition and mood when found in combination with stimulants such as caffeine, as it is found in the camellia Sinensis plant.
- Tannins help to stop diarrhea through three different mechanisms: through their astringing effect, the beneficial bacteria (Lactobacillis and Bifidobacter) promoting effect of polyphenols, and by inhibiting the growth of two bacteria (Clostridium perfringens and Clostridium difficile) which can cause infections in the intestines.10
- Antioxidants and EGCG: A great deal of research is currently being done on the various antioxidants found in green tea. The catechin EGCG (epigallocatechingallate) has been shown to protect T-helper cell11 counts from being lowered due to the effects of HIV. These same antioxidants may also help protect against Alzheimer's disease12, offering a 50% lower chance of cognitive impairment. Recently research results suggest the polyphenol antioxidants in green tea are potent cancer fighting compounds for breast, stomach, pancreas, and intestinal cancers13, and likely for others as well (especially, prostate, skin, and bladder14).
- Green tea may help to fight cavities by inhibiting the growth of bacteria (Streptococcus mutans, Streptococcus salivarius, and Escherichia coli) that may promote cavities.15
- Green tea may help prevent atherosclerosis and aid in weight loss by lowering total cholesterol and LDL cholesterol levels, raising HDL cholesterol levels; increasing fat oxidation (increasing the body's ability to burn fat); and increasing metabolism by up to 4% for 2 hours.16 In a study published in the American Journal of Clinical Nutrition (Vol. 81, No. 1, 122-129, January 2005), green tea consumption led to both a lowering of body fat and of cholesterol levels.
- Green tea may help reduce the gastrointestinal inflammation associated with ulcerative colitis and Crohn's disease.17
- Green tea has a glucose regulating effect. It does this by slowing the action of the digestive enzyme, amylase (one of the enzymes that breaks down carbohydrates). This would be beneficial in regulating diabetes.18
- Green tea has a very strong effect on the liver. It offers protective effects from toxic substances like alcohol, and may help prevent liver tumors. Catechins may help treat viral hepatitis as well.19
David Caruso-Radin is a practitioner of Traditional Chinese Medicine. He is a faculty member and the Dean of Student Affairs of the Acupuncture and Integrative Medicine College, Berkeley, as well as an instructor at the Acupressure Institute. He is a licensed acupuncturist, a nationally certified diplomate of Asian Bodywork Therapy and has trained in Medical Qigong under Suzanne Friedman, MSTCM, LAc, DMQ at AIMC Berkeley. His practice, MindBodyHerbs, is grounded in the five branches of Chinese medicine - acupuncture, herbal medicine, dietary therapy, qi gong, and bodywork. Learn more about his practice at http://www.mindbodyherbs.com/.
References
1. Carpenter, Francis R. (1974). The Classic of Tea. Hopewell, NJ: Ecco Press.
2. Chuen, L.K (2002). The Way of Tea. Hauppauge, NY: Barron’s, pg. 14.
3. http://en.wikipedia.org/wiki/Green_tea .
4. Chen, J. and Chen, T (2004). Chinese Medical Herbology and Pharmacology. City of Industry, CA: Art of Medicine Press, pg. 132.
5. Ibid.
6. Ibid.
7. http://en.wikipedia.org/wiki/Health_benefits_of_tea .
8. Fleming, Thomas, et al (eds.) (2000). PDR for Herbal Medicines. Montvale, NJ: Medical Economics Company, pg. 370.
9. http://en.wikipedia.org/wiki/L-theanine
10. Fleming, Thomas, et al (eds.) (2000). PDR for Herbal Medicines. Montvale, NJ: Medical Economics Company, pg. 370.
11. http://www.webmd.com/content/article/122/114877.htm .
12. http://www.foodnavigator.com/news/ng.asp?id=66142 .
13. Fleming, Thomas, et al (eds.) (2000). PDR for Herbal Medicines. Montvale, NJ: Medical Economics Company, pg. 370.
14. http://www.umm.edu/altmed/ConsHerbs/GreenTeach.html .
15. Fleming, Thomas, et al (eds.) (2000). PDR for Herbal Medicines. Montvale, NJ: Medical Economics Company, pg. 370.
16. http://www.actabit.com/diet-nutrition/how-effective-is-green-tea-for-weight-loss .
17. http://www.umm.edu/altmed/ConsHerbs/GreenTeach.html .
18. http://www.umm.edu/altmed/ConsHerbs/GreenTeach.html .
19. http://www.umm.edu/altmed/ConsHerbs/GreenTeach.html .
|
