Japanese Green Tea's Positive Effects on Hepatitis, NAFLD, and other Liver Diseases

Japanese green tea is known to have positive effects in reducing the risk of several liver-related diseases.

Here we'll jump into how it can help reduce the risk of hepatitis and fatty liver disease. (non-alcoholic fatty liver disease, or NAFLD)

Introduction to Liver Diseases

There are several causes of liver diseases, but a common underlying cause is the inflammation of the liver, also called hepatitis.

Viral hepatitis, or hepatitis caused by viruses, is a widespread disease in Singapore. In the case of the most common Hepatitis B, roughly 6% of adults are carriers of this disease.

When hepatitis B is not cured and progresses to a serious chronic illness called Chronic Hepatitis B (CHB), this becomes a severe issue. This is Singapore's most common cause of liver disease [1].

When hepatitis continues to occur, this eventually can lead to liver cirrhosis. This is a state of the liver where its scar tissues created from long-term liver damage prevent the liver from functioning properly.

This disease can then lead to liver cancer or liver failure.

Fatty liver disease is also common, in which the liver stores extra fat. This disease will mostly have no symptoms and no severe problems. However, in some cases, it can also lead to liver damage.

"Non-alcohol related fatty liver disease," or NAFLD, occurs in people who aren't heavy drinkers of alcohol.
There are no formal studies on the prevalence of NAFLD in Singapore. Still, a study showed 40% of adults to have it, concluding that it "suggests a significant local occurrence of NAFLD in the community including non-obese individuals." [2]


Japanese Green Tea and Liver Diseases

The substance EGCG, a type of green tea catechin, has shown promising effects in reducing the risks of liver diseases by affecting the cause of the inflammation of the liver.

For viral hepatitis, not only has it shown that green tea catechins help inhibit the infection of the virus, but it also inhibits the replication of the virus. These mechanisms were observed for both Hepatitis B [3] and Hepatitis C [4].

These experiments showed that having green tea catechin within the body beforehand is essential in preventing hepatitis infection.

For NAFLD, green tea catechins improve overall fat and glucose metabolism, prevent liver inflammation and hinder disease progression. [5]


How to Effectively take Green Tea

The key is to have tea catechins within the body consistently.

The threshold for effectiveness is thought to be 1,000 mg of catechin. Based on 180 ml cups, this would amount to roughly 6 cups. [6]

This recommendation indicates a high amount of catechin daily. This threshold may lead you to absorb this via supplements instead. There are several types of green tea extract supplements in the market.

However, consuming green tea catechin through supplements is not recommended.

While EGCG is safe when taken through natural tea infusions, liver damage risks have been reported when high doses are consumed as a supplement. [7]
The recommended EGCG intake by supplement is only 300mg per day.

Therefore it is crucial to choose the right type of green tea to maximize the number of green tea catechins and safely absorb them.


Choosing the Right Green Tea Type

Japanese green tea is highly recommended when looking for green tea with catechin. It contains one of the highest levels of EGCG in the world.

Among the various types of Japanese green tea, Sencha and Tamaryokucha are the major types that contain the most EGCG. Make sure you find these types of green tea to maximize the liver-related health benefits.

Another thing to consider is the preparation of the tea.

There are several types of green tea catechins, and not all of them dissolve in low water temperatures. EGCG requires temperatures of 80 degrees Celsius and above to effectively dissolve in water.

Make sure you prepare the Sencha or Tamaryokucha in hot water to reap the benefits mentioned here.


Author Yuki

Yuki

Yuki is the Editor-in-Chief AND Community Manager at Tealife. He bleeds Japanese Tea and loves being a part of the Japanese Tea journey of others. Writes, does events, conducts tasting sessions, drinks, drinks and drinks tea! Easily accessible - hit him up on whatsapp (+65) 85882980.


References

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6024054/

[2] Goh GB, Kwan C, Lim SY, Venkatanarasimha NK, Abu-Bakar R, Krishnamoorthy TL, Shim HH, Tay KH, Chow WC. Perceptions of non-alcoholic fatty liver disease - an Asian community-based study. Gastroenterol Rep (Oxf). 2016 May;4(2):131-5. doi: 10.1093/gastro/gov047. Epub 2015 Oct 12. PMID: 26463276; PMCID: PMC4863187.

[3] Lai, YH., Sun, CP., Huang, HC. et al. Epigallocatechin gallate inhibits hepatitis B virus infection in human liver chimeric mice. BMC Complement Altern Med 18, 248 (2018). https://doi.org/10.1186/s12906-018-2316-4

[4] Ciesek S, von Hahn T, Colpitts CC, Schang LM, Friesland M, Steinmann J, Manns MP, Ott M, Wedemeyer H, Meuleman P, Pietschmann T, Steinmann E. The green tea polyphenol, epigallocatechin-3-gallate, inhibits hepatitis C virus entry. Hepatology. 2011 Dec;54(6):1947-55. doi: 10.1002/hep.24610. PMID: 21837753.

[5] Tan Y, Kim J, Cheng J, Ong M, Lao WG, Jin XL, Lin YG, Xiao L, Zhu XQ, Qu XQ. Green tea polyphenols ameliorate non-alcoholic fatty liver disease through upregulating AMPK activation in high fat fed Zucker fatty rats. World J Gastroenterol. 2017 Jun 7;23(21):3805-3814. doi: 10.3748/wjg.v23.i21.3805. PMID: 28638220; PMCID: PMC5467066.

[6] Suzuki T. 肝疾患予防作用. 茶の健康効果20選

[7] Dekant W, Fujii K, Shibata E, Morita O, Shimotoyodome A. Safety assessment of green tea based beverages and dried green tea extracts as nutritional supplements. Toxicol Lett. 2017 Aug 5;277:104-108. doi: 10.1016/j.toxlet.2017.06.008. Epub 2017 Jun 24. PMID: 28655517.