High blood pressure is a problem that one in two Japanese people over the age of 20 has.

However, you can prevent your high blood pressure by drinking green tea.

In this article, I’m going to introduce the basic knowledge of high blood pressure and how to prevent it by drinking green tea.

The risk of high blood pressure

High blood pressure can cause diseases such as thyroid and adrenal glands, and is at risk of death in the worst case.

The causes of such high blood pressure are drinking, excessive salt intake and stress. Some people are also more prone to high blood pressure due to heredity.

According to the Ministry of Health, Labor and Welfare, one in two Japanese people over the age of 20 currently suffer from high blood pressure.

Green tea prevents high blood pressure

Green tea contains following ingredients that prevent high blood pressure.


Catechins in green tea have the effect of suppressing the action of “angiotensin I converting enzyme” which causes high blood pressure.

In fact, one study found that people who drink green tea are 35% less likely to die from a stroke in men and 42% lower rates in women than those who don't drink it.


GABA (gamma-aminobutyric acid) is an ingredient that is formed by changing glutamic acid contained in tea leaves.

GABA has the function of inhibiting a substance called “noradrenaline” that constricts blood vessels, and prevents the rise of blood pressure.


Theanine is a type of amino acid that is specific to green tea and helps prevent high blood pressure by dilating blood vessels.

Taking theanine relaxes your body and improves your blood circulation, which can be beneficial when you want to concentrate on your work or studies.

How to drink green tea to prevent high blood pressure

I will introduce how to drink green tea effectively to prevent high blood pressure.

Use hot water

Catechins, which prevent high blood pressure, have the property of being easily dissolved in hot water.

Therefore, it is possible to take in more catechins by brewing tea with hot water.

On the other hand, water makes it difficult for catechins to leach out, so if you want to get a lot of catechins, you should avoid brewing tea with water.

Choose Gyokuro or Matcha

Theanine, an ingredient that prevents high blood pressure, is contained a lot in fine teas such as Gyokuro, Matcha and high grade Sencha (steeped green tea).

This is because theanine is also an ingredient of the umami, and it is found in fine teas where the umami is important.

Brewing them with ice water will help reduce the leaching of the stimulant caffeine. So you'll feel the effects of theanine more clearly.

Choose Gabalong tea

GABA, an ingredient that prevents an increase in blood pressure, is produced by leaving raw tea leaves in an anoxic conditions for several hours.

Green tea made in this way is called “Gabalong tea”.

If you choose Gabalong tea, you can take in more GABA, so it is recommended when you are worried about your blood pressure.

January 09, 2023