Fighting the Flu with Japanese Green Tea Catechins

The Flu, or influenza, is a highly contagious viral disease. It is very relevant in Singapore as well.

According to the National Centre of Infectious Diseases, the disease "occurs all year round in Singapore with small peaks in the middle and the end/beginning of the year."

Let's see how we can fight influenza with Japanese Green Tea.

This article was last modified December 11th, 2022. by Yuki

Some people may have different symptoms. For people considered high-risk, it is essential to consider prevention, such as taking the flu vaccine.

According to MOH, some of the vulnerable groups will be the below. [2]

  • People of ages 65 years and above.
  • Children between 6 months and five years old.
  • People which chronic disorders of the lungs, including asthma or heart.
  • People who have chronic metabolic diseases, including diabetes.
  • People with kidney malfunctions.
  • People with blood disorders.
  • People with HIV.
  • Children and teenagers between 6 months and 18 years old who are receiving long-term aspirin therapy.
  • Women who are in the second or third trimester of pregnancy.

Let's see how drinking Japanese Green Tea can help prevent the Flu.

How effective is Japanese Green Tea in the prevention of Flu?

Let's jump into some studies conducted in Japan that indicate the effectiveness of Japanese green tea in preventing the Flu.

A study was conducted on 2,050 kids in an elementary school in the Shizuoka prefecture of Japan.

It was observed that students drinking 1-3 cups of Green Tea per day had a 38% decrease in the probability of catching the Flu. For students drinking 3-5 cups of green tea per day, they had a reduction of 46% probability of catching the Flu. In this experiment, 1 cup was measured as 200 mL of tea.

In another research conducted on 197 healthcare workers working in healthcare facilities for the elderly in Higashimurayama, Japan, it was observed that the infection rate of influenza for people receiving green tea catechin of 378 mg/day and theanine of 210 mg/day in capsules was 4.1%, as opposed to those who didn't have an infection rate of 13.1%

We still require more evidence to reach a definitive conclusion on green tea's effectiveness in preventing the Flu. However, these studies show the promising potential that Japanese Green Tea has.

Let's dive into some of the science behind how green tea contributes.

How does Japanese Green Tea Help Reduce the Risks of Catching the Flu?

Green Tea Catechins are nutrients that are prominent in Japanese Green Tea. This substance is responsible for several of the health benefits associated with green tea, and reducing the risk of the Flu is one of them.

Influenza viruses have proteins called hemagglutinin (HA) on their surface. These proteins act as receptors and bind to red blood cells. This binding is how the flu infection begins in the human cell.

The Catechins in green tea attach to these receptor proteins and stop the viruses from attaching to human cells.

Additionally, green tea catechins hinder virus replication and cause cell death in infected cells.

Aside from directly affecting the influenza virus, green tea also helps by enhancing the Immune system.

One of the Catechins found in Japanese Green tea, the EGC, has shown effectiveness in improving the functions of the cells within the immune system.

Also read enhancement of immunity.

Finding the Right Tea to Prevent Influenza

As indicated above, the key to fighting against Influzena is to maximize the intake of Green Tea Catechins.

Drinking Japanese green tea makes a lot of sense, as it is one of the most potent forms of tea when it comes to green tea catechin intake.

There are several types of Japanese green tea. Matcha and Houjicha might be some types of Japanese green tea that you are familiar with. While these teas also have fantastic health benefits, they are relatively low in green tea catechin content and may not help the risk of influenza infection as much as others.

Matcha is a Japanese green tea made to deliberately reduce the amount of catechin. This is to achieve a better tea taste, as the reduction of catechin reduces the astringency of the tea while increasing the umami.

Matcha has other health benefits, such as reducing anxiety and improving mental health, but it does not protect the body from the Flu as much as other forms of Japanese tea.

Houjicha is also a famous type of Japanese green tea.

It is manufactured through an additional roasting process. This extra process breaks down the catechins within the tea. This results in a light and fragrant tea that has fantastic relaxation effects. However, it does not help the body fight against the Flu as other Japanese tea.

We recommend basic Japanese Teas such as Sencha and Tamaryokucha to maximize catechin intake.
Sencha and Tamaryokucha are not altered to reduce the amounts of catechin within the leaves.

Drinking these daily gives good protection against the disease.

How to Prepare the Tea to Maximize Catechin Intake

Green Tea Catechins are relatively difficult to dissolve in water. They are more soluble in hot water than in cold water. The key to maximizing the catechin intake is to prepare the tea using boiling water.

This goes against the typical recommendations for preparing Sencha and Tamaryokucha.

Usually, the recommendation is to infuse the tea in water temperatures of 70 degrees or so. The lower temperature reduces the volume of catechins seeping into the tea, reducing the astringency and enhancing the taste.

However, when drinking for health, it's better to use boiling water as long as the astringency levels are something you can tolerate.

Author 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.




[3] Park M, Yamada H, Matsushita K, Kaji S, Goto T, Okada Y, Kosuge K, Kitagawa T. Green tea consumption is inversely associated with the incidence of influenza infection among schoolchildren in a tea plantation area of Japan. J Nutr. 2011 Oct;141(10):1862-70. doi: 10.3945/jn.110.137547. Epub 2011 Aug 10. PMID: 21832025.

[4] Matsumoto K, Yamada H, Takuma N, Niino H, Sagesaka YM. Effects of green tea catechins and theanine on preventing influenza infection among healthcare workers: a randomized controlled trial. BMC Complement Altern Med. 2011 Feb 21;11:15. doi: 10.1186/1472-6882-11-15. PMID: 21338496; PMCID: PMC3049752.