HOME > Med in Japan Newsletter No.3 December 2012 > Health Tips: The Power of Japanese Green Tea

Health Tips: The Power of Japanese Green Tea

While Japan may be best known for its exports of automobiles and electronic goods, it is also known for its exports of Japanese green tea. Green tea is widely consumed both inside and outside of Japan by people of all ages. In this issue, we introduce some of the medical reasons for why Japanese green tea has developed such a great reputation.
Green tea leaves, which have a slightly astringent taste, contain various antioxidants and anti-cancerous substances. Among these is the polyphenol called “Catechin” or Epigallocatechin-3-gallate (EGCG). Several medical studies show Japanese green tea to aid in the prevention of numerous diseases, including Sjogren's syndrome, renal damage, hypertension, inflammation, oxidative stress, gastric carcinoma, prostate cancer, and others.

The effects of Catechin include the inhibition of cancer development, induction of cancer cell apoptosis (self-destruction), and synergy with COX-II inhibitor. A Japanese research group from Saitama Cancer Center has concluded that the combination of Japanese green tea EGCG with anticancer drugs can cause a decrease in tumor size and induce cancer cell self-destruction.

Regarding Japanese green tea's anti-oxidative qualities, experiments with Japanese green tea performed on rats by Dr. Itoh and group of urologists from Nagoya City University Graduate School of Medical Sciences show preventive effects on oxidative stress that can otherwise cause the development of kidney stones. The researchers were also able to induce cancer cell apoptosis in rats with hepatocellular carcinoma using only Japanese green tea.

Japanese green tea has gained in reputation around the world and is available in various forms. As well as its traditional use as a beverage infused in hot water, it is also used in baked goods, canned and bottled beverages, ice-cream, cologne, medical compounds (such as plasters, gauze, and foot pads), and even sanitary napkins!

We highly recommend that you acquire a taste for Japanese green tea during your next visit to Japan.


[1] Suganuma M, Saha A, Fujiki H. New cancer treatment strategy using combination of green tea cathechins and anticancer drugs. Cancer Sci. 2011; 102(2):317-23.

[2]Ohno S, Yu H, Dickinson D, Chu TC, Ogbureke K, Derossi S, et al. Epigallocatechin-3-gallate modulates antioxidant and DNA repair-related proteins in exocrine glands of a primary Sjogren’s syndrome mouse model prior to disease onset. Autoimmunity. 2012;22849293.

[3] Yokozawa T, Noh JS, Park CH. Green tea polyphenols for the protection against renal damage caused by oxidative stress. Evid Based Complement Alternat Med. 2012;2012:845917.

[4] Itoh Y, Yasui T, Okada A, Tozawa K, Hayashi Y, Kohri K. Preventive effects of green tea on renal stone formation and the role of oxidative stress in nephrolithiasis. J Urol. 2005 Jan;173(1):271-5.

Med in Japan Newsletter No.3 December 2012