Eating matcha cookies lowers stress! This is according to bona fide scientists.
Yeah yeah we all know that tea can reduce stress, but did you get the cookies part?!
When I’m stressed, I eat cookies. Lots of cookies. Especially my own made-from-scratch cookies. Usually with a cup of tea. But now I have scientific proof to support my cookie–tea habit. Except that I need to start baking the tea into the cookies.
Matcha in cookies and other baked treats is very mainstream now, as these Oreos attest:And matcha is a natural in French macarons:
But there is matcha (sometimes called ceremonial grade matcha)—and there are powdered teas that are called matcha.
The former is the high-quality, expensive, shaded, stone-ground tea of the tea ceremony. The latter includes inexpensive, lower-quality matcha (culinary grade) as well as low-grade green tea that has been ground into a powder. (See my earlier post about the difference.)
The problem is that in Japan these are all called matcha. While the Japanese know the difference, here in the U.S., where many are just now discovering matcha, this leads to a lot of confusion. If you don’t know there is a difference, why would you pay a lot of money for a small tin of matcha from a tea store when you could buy a huge bag of it at Costco?
And if you don’t know there is a difference, you wouldn’t realize that all those “matcha” sweets aren’t made from the tea grade of matcha, which would be tremendously cost prohibitive. Rather, they’re made with culinary matcha or green tea powder. And that’s fine, as long as you know what you’re getting (and paying for).
So back to that scientific study, where this differentiation is critical to correctly interpreting the results.
Keiko Unno and colleagues tested the stress-reducing properties of matcha cookies.
Their test subjects were pharmaceutical students, certainly a stressed population. They weren’t allowed to ingest anything that contained caffeine and/or theanine (the amino acid unique to tea and one type of mushroom), and then were given 3 cookies a day, containing either matcha or a placebo-matcha. The effect of the matcha was measured by salivary amylase, a digestive tract enzyme.
To give you an idea of the relationship between drinking matcha vs eating it in a cookie:
- 1.5 g (0.05 oz) of matcha is used to make 100 ml (3.4 oz) of tea
- 4.5 g (0.16 oz) of matcha was used to make 3 cookies
So each student had the equivalent of 3 cups of matcha tea per day.
And the results?
Yes, matcha did reduce stress, even when baked into a cookie. And you can’t attribute this to the stress-reducing enjoyment of simply eating cookies because the placebo-matcha cookies didn’t demonstrate the same effects as the matcha ones.
However, the matcha used in this study was not culinary matcha. Rather, it was that made from tencha. And 3 cookies required a lot of matcha, as shown here:
But why did the scientists use the expensive version?
Because high-grade matcha is made from leaves that have been shaded before harvest; non-shaded leaves are used to make cheap matcha or low-grade powdered green tea. The difference?
- Shaded leaves: theanine levels are high
- Sunlit leaves: theanine levels are low because theanine breaks down into glutamate and ethyl amine, with glutamate used to synthesize the catechin (polyphenol) EGGG (therefore, low theanine, high EGGG)
Theanine has a calming effect, and for matcha to reduce a person’s stress, it has to have enough theanine to counteract the high level of caffeine that matcha contains. Because buds and young leaves are used, matcha contains a lot of caffeine (more mature leaves contain less caffeine).
Simply put, caffeine and EGGG stimulate whereas theanine and arginine (the next most abundant amino acid in Japanese green tea) calm. To get high levels of theanine, you have to protect the leaves from sunlight. And to see measurable stress reduction in people, the ratio of caffeine and EGGG to theanine and arginine must be 2 or less. If not, the stimulating caffeine and EGGG have more impact than the calming amino acids. The desired ratio is obtainable only with shaded tea leaves.
So yes, go ahead and add that powdered green tea to make delicious baked goods and lattes, and yes, there will probably be some benefits due to the tea content, but be aware that this does not replicate the research findings.
Furthermore, although the researchers (Unno et al. 2019; emphasis mine) say that a:
daily intake of matcha with a low CE/TA molar ratio in confectioneries may benefit people who do not drink green tea, and serve as a simple and practical way to prevent the accumulation of stress,
they are completely mum about the effects of financial stress when you shell out big bucks to buy that all that high-grade matcha to dump into cookie batter—or the emotional stress of gaining weight from eating all those cookies!Note: I made the matcha cookies shown here using this recipe given in the study, but with no baking instructions, I did slightly overbake them:
Matcha (4.5 g) was mixed with flour 31.5 g, butter 26.1 g, sugar 13.5g and egg yolk 1.8 g, molded into three cookies, then baked. (Unno 2019)
Source: “Stress-reducing effect of cookies containing matcha green tea: essential ratio among theanine, arginine, caffeine and epigallocatechin gallate,” by K. Unno et al., Heliyon 5 (2019) e01653.