T is for...
If a cuppa can’t fix the problem, I don’t want to know about it.
T is for Theanine
It’s actually L-theanine, but for the purpose of this T is for…article let’s overlook that.
L-theanine is an amino acid found naturally in tea leaves. It is the reason the energy from a cup of green tea feels fundamentally different to a coffee, more settled, more focused, less wired.
Here is what it does. L-theanine triggers alpha brain waves, the same ones active during meditation, creative flow, and deep relaxation. It promotes calm without sedation.
Paired with caffeine, which tea also contains, it becomes even more interesting. The caffeine sharpens focus. The L-theanine smooths the jitteriness. Together they produce a kind of clean, sustained alertness that coffee on its own can’t deliver.
A 2024 clinical trial found that daily L-theanine reduced perceived stress by nearly 18%, improved sleep quality, and enhanced cognitive attention. A 24-month randomised trial found a 33% improvement in overall cognitive performance compared to placebo.
Not all teas are equal when it comes to L-theanine though.
Matcha is the standout. Because matcha is made from whole ground tea leaves rather than steeped and discarded ones, you consume the entire leaf, meaning a significantly higher concentration of L-theanine than any other form of tea.
Green tea is where L-theanine was first identified and most studied. A standard cup contains around 20mg, enough to take the edge off and pair beautifully with its moderate caffeine content.
White tea is the least processed of all, made from young leaves and buds that are simply dried. The lowest caffeine, the most delicate flavour, contains about 10mg of L-Theanine per cup.
Black tea is the most oxidised, giving it that bold, malty character. It contains less L-theanine than green, but still delivers the caffeine and theanine effect.
The catch is that a standard cup of green tea contains around 20mg of L-theanine, and most studies showing meaningful results use 200 to 400mg daily. So if you want the full effect, a supplement is worth considering. But the cup of tea is still worth drinking.
For the compounding daily dose and a solid replacement for coffee.
One last thing. To milk or not to milk? A splash is absolutely fine and makes no meaningful difference to your L-theanine levels. But high amounts of milk have been shown to significantly reduce the L-theanine content of your cup, so for drinks such as a milky matcha consider a plant based alternative.
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