Health Benefits of Tea

There are many myths surrounding the benefits of tea, in particular green tea. The health benefits of green tea have attracted much attention from academics and the media. The PubMed database alone contains more than 1,000 studies on green tea. There are some bold claims from various websites saying it is an anti-ageing drink that can cure cancer and a miracle beverage for weight loss. We at Chinese Tea Garden are just a group of tea lovers who enjoy the taste of fine tea; the health benefits are just a bonus. There are many types of teas and many facts (and fictions) that come with them. We will try to present a unbiased view to the subject matter, focusing on the facts and with proper references to the source material, so that you can make up your own mind. There is also a section on the website focusing on information about Tea in media.

Below is a list of the benefits of regular intake of tea:

  • Protection against Coronary Heart Disease by eliminating free radical[1,2]
  • Inhibits Atherosclerosis (Hardening of Artery) by lowering LDL cholesterol[3]
  • Speeds recovery from injuries and reduces inflammation[4]
  • Lower Blood Pressure[5]
  • Cancer prevention[6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17]
  • Strengthens bones and teeth [18,19]
  • Promotes fat loss [20, 21]
  • Protection against cognitive decline [22,23,24,25]
  • Flu prevention [26]

Green tea is rich in flavonoids which are known for their health enhancing properties, which include catechins and their derivatives. The main type of catechine in green tea is epigallocatechin-3-gallate (EGCE), which is believed to be a strong antioxidant, even stronger than vitamin E and vitamin C. EGCE is also present in Woolong and black tea, but in smaller quantities. These catechines are efficient free radical scavengers which is the main reason why people believe tea is good for fighting against cancer and keeping the body healthy.

Bibliography

[1] 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. PMID:15226633.

[2] Juhel C, Armand M, Pafumi Y, Rosier C, Vandermander J, Lairon D. Green tea extract (AR25(R)) inhibits lipolysis of triglycerides in gastric and duodenal medium in vitro. J Nutr Biochem. 2000 Jan;11(1):45-51. PMID:15539342.  

[3] Vinson JA, Teufel K, Wu N. Green and black teas inhibit atherosclerosis by lipid, antioxidant, and fibrinolytic mechanisms. J Agric Food Chem. 2004 Jun 2;52(11):3661-5. PMID:15161246.

[4] Stephanou A. Role of STAT-1 and STAT-3 in ischaemia/reperfusion injury. J Cell Mol Med. 2004 Oct-Dec;8(4):519-25. PMID:15601580.

[5] Yang YC, Lu FH, Wu JS, Wu CH, Chang CJ. The protective effect of habitual tea consumption on hypertension. Arch Intern Med. 2004 Jul

[6] Geetha T, Garg A, Chopra K, Pal Kaur I. Delineation of antimutagenic activity of catechin, epicatechin and green tea extract. Mutat Res. 2004 Nov

[7] Azam S, Hadi N, Khan NU, Hadi SM. Prooxidant property of green tea polyphenols epicatechin and epigallocatechin-3-gallate: implications for anticancer properties. Toxicol In Vitro. 2004 Oct;18(5):555-61. PMID:15251172.

[8] Baek SJ, Kim JS, Jackson FR, Eling TE, McEntee MF, Lee SH. Epicatechin gallate-induced expression of NAG-1 is associated with growth inhibition and apoptosis in colon cancer cells. Carcinogenesis. 2004 Aug 12; [Epub ahead of print]. PMID:15308587.

[9] Chen D, Daniel KG, Kuhn DJ, Kazi A, Bhuiyan M, Li L, Wang Z, Wan SB, Lam WH, Chan TH, Dou QP. Green tea and tea polyphenols in cancer prevention. Front Biosci. 2004 Sep 01;9:2618-31. PMID:15358585.

[10] Chow HH, Hakim IA, Vining DR, et al. Modulation of human glutathione s-transferases by polyphenon e intervention. Cancer Epidemiol Biomarkers Prev. 2007 Aug;16(8):1662-6. PMID:17684143.

[11] Fassina G, Vene R, Morini M, Minghelli S, Benelli R, Noonan DM, Albini A. Mechanisms of inhibition of tumor angiogenesis and vascular tumor growth by epigallocatechin-3-gallate. Clin Cancer Res. 2004 Jul 15;10(14):4865-73. PMID:15269163.

[12] Gates MA, Tworoger SS, Hecht JL, De Vivo I, Rosner B, Hankinson SE. A prospective study of dietary flavonoid intake and incidence of epithelial ovarian cancer. Int J Cancer. 2007 Apr 30; PMID:17471564.

[13] Huh SW, Bae SM, Kim YW, Lee JM, Namkoong SE, Lee IP, Kim SH, Kim CK, Ahn WS. Anticancer effects of (-)-epigallocatechin-3-gallate on ovarian carcinoma cell lines. Gynecol Oncol. 2004 Sep;94(3):760-8. PMID:15350370.

[14]Jian L, Lee AH, Binns CW. Tea and lycopene protect against prostate cancer. Asia Pac J Clin Nutr. 2007;16 Suppl 1:453-7. PMID:17392149.

[15] Kurahashi N, Sasazuki S, Iwasaki M, Inoue M; Shoichiro Tsugane for the JPHC Study Group. Green Tea Consumption and Prostate Cancer Risk in Japanese Men: A Prospective Study. Am J Epidemiol. 2007 Sep 29. PMID:17906295.

[16]Larsson SC, Wolk A. Tea consumption and ovarian cancer risk in a population-based cohort. Arch Intern Med. 2005 Dec 12-26;165(22):2683-6. PMID:16344429.

[17] Lu QY, Jin YS, Pantuck A, Zhang ZF, Heber D, Belldegrun A, Brooks M, Figlin R, Rao J. Green tea extract modulates actin remodeling via Rho activity in an in vitro multistep carcinogenic model. Clin Cancer Res. 2005 Feb 15;11(4):1675-83. PMID:15746073.

[18] Muraki S, Yamamoto S, Oka H, Yoshimura N, Kawaguchi, H, Orimo H, Nakamura K. Green tea drinking is associated with increased bone mineral density in elderly women. Study P187SA, presented at the International Osteoporosis Foundation World Congress on Osteoporosis, Toronto, Canada, June 5, 2006.

[19] Devine A, Hodgson JM, Dick IM, Prince RL. Tea drinking is associated with benefits on bone density in older women. Am J Clin Nutr. 2007 Oct;86(4):1243-7. PMID:17921409.

[20] Zheng G, Sayama K, Okubo T, Juneja LR, Oguni I. Anti-obesity effects of three major components of green tea, catechins, caffeine and theanine, in mice. In Vivo. 2004 Jan-Feb;18(1):55-62. PMID:15011752.

[21] Nagao T, Komine Y, Soga S, Meguro S, Hase T, Tanaka Y, Tokimitsu I. Ingestion of a tea rich in catechins leads to a reduction in body fat and malondialdehyde-modified LDL in men. Am J Clin Nutr. 2005 Jan;81(1):122-9. PMID:15640470.

[22] 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. PMID:15350981.

[23] Reznichenko L, Amit T, Zheng H, Avramovich-Tirosh Y, Youdim MB, Weinreb O, Mandel S. Reduction of iron-regulated amyloid precursor protein and beta-amyloid peptide by (-)-epigallocatechin-3-gallate in cell cultures: implications for iron chelation in Alzheimer's disease. J Neurochem. 2006 Mar 15; PMID:16539659.

[24] Park HJ, Shin DH, Chung WJ, Leem K, Yoon SH, Hong MS, Chung JH, Bae JH, Hwang JS. Epigallocatechin gallate reduces hypoxia-induced apoptosis in human hepatoma cells. Life Sci. 2006 Jan 26;. PMID:16445947.

[25] Haque AM, Hashimoto M, Katakura M, Tanabe Y, Hara Y, Shido O. Long-term administration of green tea catechins improves spatial cognition learning ability in rats. J Nutr. 2006 Apr;136(4):1043-7. PMID:16549472.

[26] Song JM, Lee KH, Seong BL. Antiviral effect of catechins in green tea on influenza virus. Antiviral Res. 2005 Nov;68(2):66-74. Epub 2005 Aug 9. PMID:16137775.