10 Reasons to Drink Green Tea

Courtesy of Dr. Weil on Healthy Aging, Your Online Guide to the Anti-Inflammatory Diet.

Many nutrition experts contend that pure water is the most healthful thirst quencher. While that’s certainly an excellent choice – and far better than fruit juices or soda, both of which can spike blood sugar and lead to weight gain – I believe there’s an even better one: green tea.

Green tea comes from the lightly steamed leaves of the Camellia sinensis plant. It was first brewed in China during the reign of Emperor Shennong in 2737 BC. Long revered in many cultures and traditions throughout Asia, its popularity has soared in the West – particularly the U.S. – in the past two decades.

That’s fortunate, as research into this ancient beverage has validated its longstanding reputation for supporting physical and mental health. Scientific inquiries report that green tea:

  1. contains antioxidants, including polyphenols such as epigallocatechin gallate (EGCG), which can powerfully quench damaging “free radicals,” metabolic byproducts that are chemically reactive and can damage cells. According to a study published in the European Journal of Clinical Nutrition, the polyphenols found in green tea provide six times the radical-quenching potential of those found in black tea.
  2. supports cardiovascular and metabolic health. According to a study published in the Journal of the American College of Nutrition, researchers found subjects consuming five or more cups of green tea per day were less likely to develop hypertension (high blood pressure) and diabetes, or die of cardiovascular disease or stroke. Researchers also found in animal studies that EGCG improved heart health by preventing “overload-induced cardiac hypertrophy” – or thickening of the heart muscles.
  3. helps to prevent fatty buildup in arteries, according to a 2013 study published in the Journal of Biological Chemistry. The investigation found EGCG from green tea may reduce cholesterol levels, ultimately assisting in lowering the risk of cardiovascular disease.
  4. can increase energy and mental focus. Green tea contains a small amount of caffeine, which a 2008 study in Nutrition Bulletin found can improve mood, cognitive function and physical performance. Green tea contains less caffeine than does coffee, and provides L-theanine, an amino acid shown to promote a state of calm awareness. Result: green tea provides the benefits of alertness associated with caffeine without the “jittery” feeling often experienced as a side effect of coffee.
  5. quickly calms and relaxes. L-theanine exhibits anti-anxiety effects by increasing dopamine levels in the brain, and also appears to decrease blood pressure. A study published in Trends in Food Science & Technology found green tea produces relaxing effects without drowsiness only 40 minutes after ingestion.
  6. facilitates the burning of body fat. Green tea promotes the body’s ability to burn fat through thermogenesis and fat oxidation. A study published in The American Journal of Clinical Nutrition found the combination of polyphenols and caffeine from an extract of green tea resulted in a “significant increase” of energy expenditure compared to placebo.
  7. may help prevent skin damage and cancer. An animal study published in Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis found green tea appears to protect against skin papillomas and tumors induced by UVA and UVB light. The study also reported that sun-induced inflammatory changes were “slightly lowered” by tea consumption.
  8. may improve bone health. A study published in Nutrition Research found the bioactive components of green tea may help decrease the risk of fracture by improving bone mineral density.
  9. may lower the risk of certain types of cancer. Studies have examined green tea’s potential role in lowering risks of breast, ovarian, bladder, esophageal, and prostate cancers. More studies are needed, but research so far is promising.
  10. improves insulin sensitivity and may help protect against diabetes, as well as against rapid rises and subsequent crashes in blood sugar levels that lead to fatigue, irritability, and food cravings. A study in Annals of Internal Medicine found consumption of green tea (as well as black tea and coffee), was associated with a reduced risk of type 2 diabetes.

Bottom line: green tea is a delicious, healthy drink that should be part of your daily diet. Its health benefits are best realized when it’s served hot and with a wedge of lemon, but it can be enjoyed chilled or even iced. There are many varieties of green tea, so experiment until you find one you like!

Sources:
Serafini, M., A. Ghiselli, and A. Ferro-Luzzi. “In vivo antioxidant effect of green and black tea in man.” European journal of clinical nutrition 50, no. 1 (1996): 28-32.

Wolfram, Swen. “Effects of green tea and EGCG on cardiovascular and metabolic health.” Journal of the American College of Nutrition 26, no. 4 (2007): 373S-388S.

Kim, Hae-Suk, Vedrana Montana, Hyun-Ju Jang, Vladimir Parpura, and Jeong-A. Kim. “Epigallocatechin Gallate (EGCG) Stimulates Autophagy in Vascular Endothelial Cells A POTENTIAL ROLE FOR REDUCING LIPID ACCUMULATION.” Journal of Biological Chemistry 288, no. 31 (2013): 22693-22705.

Ruxton, C. H. S. “The impact of caffeine on mood, cognitive function, performance and hydration: a review of benefits and risks.” Nutrition Bulletin 33, no. 1 (2008): 15-25.

Juneja, Lekh Raj, Djong-Chi Chu, Tsutomu Okubo, Yukiko Nagato, and Hidehiko Yokogoshi. “L-theanine—a unique amino acid of green tea and its relaxation effect in humans.” Trends in Food Science & Technology 10, no. 6 (1999): 199-204.

Dulloo, Abdul G., Claudette Duret, Dorothée Rohrer, Lucien Girardier, Nouri Mensi, Marc Fathi, Philippe Chantre, and Jacques Vandermander. “Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans.” The American journal of clinical nutrition 70, no. 6 (1999): 1040-1045.

Record, Ian R., and Ivor E. Dreosti. “Protection by black tea and green tea against UVB and UVA+ B induced skin cancer in hairless mice.” Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 422, no. 1 (1998): 191-199.

Shen, Chwan-Li, James K. Yeh, Jay J. Cao, and Jia-Sheng Wang. “Green tea and bone metabolism.” Nutrition research 29, no. 7 (2009): 437-456.

Choan, E., Roanne Segal, Derek Jonker, Shawn Malone, Neil Reaume, Libni Eapen, and Victor Gallant. “A prospective clinical trial of green tea for hormone refractory prostate cancer: an evaluation of the complementary/alternative therapy approach.” In Urologic Oncology: Seminars and Original Investigations, vol. 23, no. 2, pp. 108-113. Elsevier, 2005.

Gao, Yu Tang, Joseph K. McLaughlin, William J. Blot, Bu Tian Ji, Qi Dai, and Joseph F. Fraumeni. “Reduced risk of esophageal cancer associated with green tea consumption.” Journal of the National Cancer Institute 86, no. 11 (1994): 855-858.

Imai, Kazue, Kenji Suga, and Kei Nakachi. “Cancer-preventive effects of drinking green tea among a Japanese population.” Preventive medicine 26, no. 6 (1997): 769-775.

Iso, Hiroyasu, Chigusa Date, Kenji Wakai, Mitsuru Fukui, and Akiko Tamakoshi. “The relationship between green tea and total caffeine intake and risk for self-reported type 2 diabetes among Japanese adults.” Annals of Internal Medicine 144, no. 8 (2006): 554-562.

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