Why matcha — what daily green tea actually does for inflammation and stress

A friend called me a few months ago and said, "Okay, explain the matcha thing. Are you drinking it because you genuinely like it, or is it one of those habits you've convinced yourself tastes good because you read it was healthy?"

I laughed, because she knows me. And the honest answer is: both, in exactly that order. I liked it first. The science came later — or rather, the science became a reason to keep doing something I was already doing anyway.

That's really what I want to write about. Not matcha as a supplement. Not matcha as a cure for anything. Matcha as a daily ritual that, it turns out, is one of the most-studied things a person can put in their body in the morning. Decades of research across inflammation, cardiovascular function, metabolic health, neuroinflammation, stress response. And you don't have to be chasing a number to benefit from any of it — you just have to drink it most mornings and not replace it with a sleeve of cookies.

This is not a post about going on a wellness journey. It's a post about a cup of tea.

How I came to it

I don't remember exactly when I switched from regular green tea to matcha. Somewhere around 2019, maybe 2020 — the years run together. What I remember is standing in a kitchen supply store and looking at a small bamboo whisk and thinking, I could do something with this. I bought the whisk, a small bowl, and a tin of ceremonial-grade powder. It took me two weeks to stop making it taste like a puddle.

Now I make it the same way every morning. Water at about 175 degrees — not boiling, boiling makes it bitter. A bamboo whisk, a ceramic bowl that belonged to Fabio's mother. I sift a teaspoon of powder into the bowl, add a splash of water, and whisk until there's a light foam. Then I add the rest of the water. The whole thing takes four minutes. I drink it before I do anything else.

Fabio started asking questions about it after about a month. That's how I knew it was doing something.

What's in matcha that isn't in plain green tea

Both are from Camellia sinensis — the same plant. The difference is how matcha is grown and processed. For the last few weeks before harvest, matcha plants are shade-covered, which forces the plant to produce more chlorophyll and, more relevant to what we're talking about, more L-theanine. Then the whole leaf is stone-ground into a fine powder.

When you drink matcha, you're not steeping and discarding the leaf — you're consuming the whole leaf. That changes the concentration of everything in it.

The two compounds most relevant for what I notice:

EGCG — epigallocatechin gallate. The primary catechin in green tea. Matcha has it at meaningfully higher concentrations than brewed green tea. Kochman and colleagues published a comprehensive review of matcha's health profile in Molecules in 2020 — the paper goes through the evidence on EGCG's effect on inflammatory signaling, oxidative stress, cardiovascular markers, metabolic function, and even neuroinflammation¹. The molecule has been studied across cancer research, cardiovascular medicine, and metabolic disease — not because it cures any of them, but because it appears to influence many of the signaling pathways those conditions share. EGCG has been found to modulate NF-κB activity — the master inflammatory switch Fabio writes about in his letter on the cascade — and to support antioxidant enzyme activity in cell and animal models.

L-theanine — an amino acid found almost exclusively in tea plants, at higher concentrations in matcha than in regular green tea. L-theanine is what creates the calm-focus feeling that is genuinely distinct from caffeine alone. It doesn't sedate. It quiets the slightly-too-loud background noise without dimming the lights. Unno and colleagues at the University of Shizuoka specifically studied matcha's stress-reducing function and found that the combination of L-theanine and EGCG together — not isolated — produced the most consistent effect on anxiety and stress markers in their study participants². The interaction between these two compounds is part of why matcha's profile is different from just taking an EGCG supplement by itself.

What I notice — and what I don't

I want to be careful here. I'm not keeping a lab notebook. I'm not running a randomized trial on myself. What I can tell you is what I observe.

What I notice: the first hour of my morning is quieter. Not sedated — I'm not a person who tolerates sedation at 7 a.m. But there's a difference between caffeinated and on edge and caffeinated and settled. Matcha, for me, is the second one. The L-theanine effect that Unno and colleagues studied is real in my experience.

What I also notice: I've been doing this for several years now. I don't have a CRP number from before and after to show you. What I do have is the pattern Sokary and colleagues laid out in a 2022 review in Current Research in Food Science — a broad evaluation of the therapeutic potential of matcha — which describes the cumulative, time-dependent nature of how dietary catechins appear to work³. You're not turning a dial in real time. You're doing something daily that shifts the background conditions over months.

What I don't notice: a dramatic transformation of anything. This is important to say. Matcha is not the thing that replaced medication or resolved a health crisis. It is a daily practice with a decades-long evidence base. Those are not the same as dramatic.

The research, briefly

I'll keep this short because Fabio is the one who writes the science letters in this family, and I don't want to pretend otherwise.

The Kochman review I mentioned¹ covers EGCG's effects on inflammatory markers, oxidative load, and metabolic signaling. It's a 2020 paper, peer-reviewed, open access, and reasonably comprehensive — it's where I'd send someone who wants the full picture.

Unno et al.'s work on stress reduction² is worth reading specifically for the L-theanine + EGCG interaction. They were looking at healthy participants under psychosocial stress — not people with conditions — which makes the findings more generalizable to daily life than a lot of supplement research.

Sachdeva and colleagues published work on EGCG's role in protecting against the kind of oxidative stress associated with chronic fatigue⁴ — which is relevant if what's wearing you out isn't just one acute thing but the accumulated weight of the day.

The safety piece: EFSA — the European Food Safety Authority — published a 2018 opinion specifically on green tea catechins and concluded that doses up to 800 mg of EGCG per day from supplements are generally well-tolerated in healthy adults⁵. A cup of matcha delivers somewhere in the range of 70-130 mg of EGCG, well within normal range. Bonkovsky published a case series in Annals of Internal Medicine in 2006 linking very high-dose green tea extract supplements to liver toxicity concerns⁶ — not from tea drinking, but from concentrated supplements at doses many times higher than what you'd get from daily tea. I mention this because I think it's worth saying: matcha consumed as a beverage and high-concentration EGCG supplements are not the same thing. Normal quantities of the former are backed by a meaningful safety record. The latter warrant more care.

Dietz and Dekker's work on phytochemicals and mood/cognition⁷ is in the background here too — the evidence base connecting dietary polyphenols to mood regulation and cognitive function has been building for years and matcha sits squarely within that pattern.

Why daily matters more than dose

This is the part I find most interesting about the research, and also the part that fits best with how I actually live.

The catechins in matcha aren't building up in your body in a way that requires a loading dose. What the research suggests — and what the Sokary review lays out — is that the effect is more about consistent presence than about peaks. Your body uses what you give it in context. Polyphenols appear to support a healthy inflammatory response not by flooding the system but by providing a steady background signal.

Fabio phrases this as the difference between an acute intervention and an environmental one. He'd know better than I would about the pharmacokinetics. What I know is that this fits my experience: missing a day doesn't matter. Missing a month probably would.

I wrote a letter about what a week of meals looks like at our house that touches on this — the polyphenol piece in particular. The matcha is part of that pattern. It's one element of a morning that also includes whole food, movement, and whatever sleep the previous night actually delivered. (Fabio wrote about sleep and inflammation — how the overnight window is when a lot of the repair work happens — and if you want to read that, here is his letter. Sleep is probably the upstream lever that makes everything else work better or worse.)

The point is: I'm not trying to hit an EGCG target. I'm building a morning that gives my body something to work with, day after day. The matcha is one reliable element of that.

How I make it

The method matters more than most people think, not because there's a ceremonial reason but because temperature changes the taste significantly.

Water at 175-180 degrees Fahrenheit. If you don't have a temperature-controlled kettle, bring water to a full boil and then let it sit for about two minutes. Boiling water makes matcha bitter — the high temperature degrades some of the catechins and brings out a harsh edge.

I use ceremonial grade. Not because it's more medicinal but because it tastes better and I'm more likely to drink it every day if I enjoy it. Culinary grade is fine for smoothies and baking; for drinking straight I want the better powder.

One heaped teaspoon into a dry bowl. A small amount of warm water — maybe two tablespoons — and whisk vigorously in a W or M pattern until the powder is fully dissolved and there's a light foam on the surface. Then I add the rest of the water. Total: about six ounces.

I drink it slowly. That's the actual ritual part.

Some mornings I make a latte with warm oat milk instead of water. Softer, slightly sweeter. The milk slows the catechin absorption a bit — there's some evidence that dairy protein binds to polyphenols in tea — so I default to water when I can, but the latte version isn't nothing. It's still matcha. I still made it with a whisk and a bowl. That matters.

What it doesn't do

Matcha does not replace anything that requires medical attention. It does not un-do a poor diet or insufficient sleep. It has not, in my experience, eliminated any particular symptom. It is not a stimulant substitute — the caffeine in matcha (roughly 60-70mg per cup, somewhat less than coffee) is gentler because of the L-theanine pairing, but it's not the same as being well-rested.

I also want to say something about the research landscape: most of the robust mechanistic work on EGCG is from cell studies and animal models. The clinical evidence — human trials — is less extensive, and the studies that exist vary in dose, duration, and population. The Kochman review is honest about this. I am not dismissing the evidence; I'm saying it's different from the kind of certainty we'd have about, say, a ten-year cardiovascular trial. I drink matcha because the evidence is genuinely interesting, not because it's conclusive in the way clinical medicine requires before prescription.

Where the formula fits

I've been asked a lot whether what we make in this family is meant to replace everyday food and habit choices. It isn't. What the formula we built for me does is support a healthy inflammatory response as part of a daily routine that already includes the fundamentals.* The supplement fits inside the life. It doesn't replace the matcha or the salmon or the sleep.

My breakfast letter has the most practical version of how I think about the morning stack — what I eat, in what order, and why. The matcha comes first. Then the food. The formula comes with breakfast. That's the rhythm.

It took me a few years to get that order right. Now it's just how mornings go.

I hope this letter finds you well — and that if you've been thinking about the matcha thing, this gives you enough to start. You don't need the expensive whisk. You don't need a specific brand. You need a reasonable powder, water at the right temperature, and most mornings.

If you have questions or want to tell me how yours turned out, you know where to find me.

Love,

— Maria

* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

References

1. Kochman J, Jakubczyk K, Antoniewicz J, Mruk H, Janda K. Health Benefits and Chemical Composition of Matcha Green Tea: A Review. Molecules. 2020;26(1):85. https://doi.org/10.3390/molecules26010085
2. Unno K, Furushima D, Hamamoto S, et al. Stress-Reducing Function of Matcha Green Tea in Animal Experiments and Clinical Trials. Nutrients. 2018;10(10):1468. https://doi.org/10.3390/nu10101468
3. Sokary S, Al-Asmakh M, Zakaria Z, Bawadi H. The Therapeutic Potential of Matcha Tea: A Critical Review of the Current Evidence. Curr Res Food Sci. 2022;6:100396. https://doi.org/10.1016/j.crfs.2022.11.015
4. Sachdeva AK, Kuhad A, Chopra K. Epigallocatechin gallate ameliorates behavioral and biochemical deficits in rat model of load-induced chronic fatigue syndrome. Basic Clin Pharmacol Toxicol. 2010;106(1):42-48. https://doi.org/10.1111/j.1742-7843.2009.00461.x
5. EFSA Panel on Food Additives and Nutrient Sources Added to Food. Scientific opinion on the safety of green tea catechins. EFSA J. 2018;16(4):5239. https://doi.org/10.2903/j.efsa.2018.5239
6. Bonkovsky HL. Hepatotoxicity associated with supplements containing Chinese herbal medicine. Ann Intern Med. 2006;144(1):68-71. https://doi.org/10.7326/0003-4819-144-1-200601030-00014
7. Dietz C, Dekker M. Effect of Green Tea Phytochemicals on Mood and Cognition. Curr Pharm Des. 2017;23(19):2876-2905. https://doi.org/10.2174/1381612823666170105151800