I haven’t written about the health benefits of green tea here on T Ching because there is just so much information out there. But during a matcha whisking event for some ex-pats living in Japan, the topic dominated the conversation, although no one knew why it was so healthy…just that it was. It occurred to me that the benefits need to be dumbed down and told in simple English! I’ll attempt to do just that.

Illustration of two bamboo umbrellas open next to a table with tea

Studies have been conducted on green tea related to everything from mental alertness, frailty, anti-aging, heart disease, skin health, gastrointestinal disorders, stroke, osteoporosis, cognitive impairment, oral health, arthritis, and obesity. As the years pass, more good news emerges about the health benefits of drinking green tea on a daily basis and as a result, green tea is here to stay.

Green tea contains polyphenols, which is a very broad class of structurally related antioxidants. A subgroup of polyphenols, known as flavan-3ols (flavanols) or catechins (pronounced cat-ah-kins), shows up big time in green tea. In fact, tea has one of the highest concentrations of catechins of all foods and beverages out there.

It also contains tannin, a polyphenol, (different from tannic acid), which produces the astringent or dry-mouth component in green tea. Basically, the tannin binds to the protein in your saliva and causes it to shrink and this is what gives you that chalky feeling on your tongue and makes you want to smack your lips.

Of course, we already know that caffeine is present but you also need to know about Theanine, or what I call the “miracle amino acid” which produces the calming effect of green tea.

Let’s Dive Deeper

Catechins are natural plant antioxidants and they show up in foods like cacao, argan oil, acai oil, berries, and vinegar to name a few. There are four main catechins in green tea but of these catechins, a very special one is only found in green tea: Epigallocatechin-3-gallate or simplified, EGCG. I have no idea who really needs to remember this but it’s getting all the fanfare because of studies showing that EGCG is anti-aging, cancer preventing and makes fat cells run for mercy. Just FYI, when teas such as black teas, oolongs, and pu’erhs are oxidized, the EGCG is more or less neutralized, so don’t grab an Earl Grey hoping for a major health hit.

The main health benefit of green tea is how rich it is in antioxidants, which, if you don’t know, protect your cells against damage from all kinds of things, including pollution, preservatives, pesticides, and even emotions! Free radicals are running wild inside your body causing damage and the antioxidants are hunting them down.

“But so many things have antioxidants – why is green tea so special?” I hear you say! The United States Department of Agriculture (USDA) published the ORAC table up until May 2012 to measure the strength of antioxidants in the foods we eat. This table gave Japanese Matcha a score of 1253, which completely outnumbers the antioxidants in superfoods like Goji berries (253 score) and Acai (60 score). Sadly the ORAC table was taken down from the USDA website because opportunist marketers abused the information to make outrageous health claims so we can’t see the chart anymore.


Theanine, or L-Theanine, is an amino acid that you find in the Camellia Sinensis leaf. It rarely shows up in anything else in nature except a type of uncommon mushroom (Bay Bolete) and, yes, the Holly tree. Luckily green tea has a lot of Theanine! Of the total content of all the amino acids in green tea, Theanine claims around 60 to 70 percent.  This amino acid is responsible for most of the flavor, especially the sweetness, and is what makes tea so talked about, particularly in terms of how a sip makes you feel. You can’t exactly feel antioxidants at work in your body, you just believe they are doing their job. Not so with Theanine. You can FEEL it!

What I find really interesting is what happens when Theanine mingles with caffeine. It’s this tango of caffeine and Theanine that gives you the bliss and clarity, which is so pronounced when you drink green tea. You need both in the proper ratio to get that feeling. The Theanine and caffeine combo also reduces physical stress and gets the creative juices flowing. This is all due to how Theanine elevates dopamine levels in the brain… The topic of caffeine in green tea could be a blog post all on its own but in a nutshell, caffeine is slowly released into the bloodstream due to metabolizing the catechins so you don’t get that jittery feeling and then crash.


In simple terms, Dopamine is a hormone (and a neurotransmitter) that is produced in your brain. It’s known as the “reward” hormone associated with good experiences. When you find a wad of cash on the street, immediately you feel an excited sensation and your heart seems to flutter. This is dopamine being released! In love? Yep, dopamine! Other effects include motivation, voluntary movement, sleep, mood, attention, focus, memory retention and learning to name but a few things.

Illustration of tea on a tray on tatami, chasen nearby

So what does this have to do with tea and health? Well, in order to produce dopamine, certain amino acids are required. These amino acids come to us in foods and drinks. But in order to produce dopamine, these amino acids need to cross what is called the “blood-brain barrier” or BBB. Think of this as a maze to get into your brain. It’s filled with tiny alleyways that block substances from getting through to the brain, like viruses for instance. Most substances can’t cross over this barrier but Theanine can.

According to doctors Hidehiko Yokogoshi and Takehiko Terashima (leaders in Theanine-based research) at the Laboratory of Nutritional Biochemistry in Shizuoka, when you drink green tea, dopamine levels are significantly increased in the brain.

It’s worth repeating that green tea is just about the only thing in nature that contains Theanine and lots of it! This means it can boost production of dopamine in the brain when you drink it. These two doctors went on to explain how Theanine also promotes Alpha wave functions in the brain and this is what causes you to have an alert yet relaxed physical and mental state. In other words, it is your personal stress management system!

It’s also a well-known anecdote in Japan that Theanine is one of the best hangover helpers out there. The benefits of Theanine are too extensive to list but suffice to say, it’s the daddy of all feel-good substances.

The Science of Flow

When I drink Japanese green tea, I find that my state is energized, not jittery, my mind is clear, and I’m really in my flow.  New ideas seem to be coming from out of nowhere, connections are being made, my intuition is bionic and life seems to be sailing along with effortless ease. Some scientists refer to this as “the relaxed yet alert state” but they are missing something essential: creative JUICE!  I call this the “Science of Flow” because green tea is the conduit to get you into a state of effortless flow where inspiration is bubbling up from inside of you. I wonder why no one seems to be talking about this major benefit! Surely I’m not the only one who experiences creative flow as I sip my favorite kabusecha. I urge you to consider drinking only green tea when embarking on a creative adventure and see how well you do. Then drop me a line to join the club!

This article has been reformatted and updated from the original March 2018 publication, when it was published in two separate parts

Images are from “Green is the New Black – the glorious rise of Japanese green tea” by author Holly Helt and is used with permission