The myth of matcha
There are many companies misquoting a certain study examining the levels of EGCG (a specific type of catechin, itself a kind of antioxidant). These companies say that matcha has 137x the level of antioxidants as green tea.
That study, like so many others, needs to be examined more carefully (and read if possible of course). But even by looking at the abstract (below) you can see how marketers have taken the "137" figure out of context (highlights are mine.):
Catechins in green tea are known to have many beneficial health properties. Recently, it has been suggested that matcha has greater potential health benefits than other green teas. Matcha is a special powdered green tea used in the Japanese tea ceremony. However, there has been no investigation to quantitate the catechin intake from matcha compared to common green teas. We have developed a rapid method of analysis of five catechins and caffeine in matcha using micellar electrokinetic chromatography. Results are presented for water and methanol extractions of matcha compared with water extraction of a popular green tea. Using a mg catechin/g of dry leaf comparison, results indicate that the concentration of epigallocatechin gallate (EGCG) available from drinking matcha is 137 times greater than the amount of EGCG available from China Green Tips green tea, and at least three times higher than the largest literature value for other green teas.
China Green Tips is, of course, a specific tea product from Starbucks, not green tea in general. Both Green Tea Guide and Matcha Mind Tea point out that 137x the level of average green tea would be dangerous.
What about powdered green tea?
What is common in Japan for those seeking to increase their dietary intake of catechin through green tea is drinking powdered green tea. In fact, on average, nearly all green teas (roasted hojicha is the exception) has more catechin than matcha if consumed in powdered form.
The analysis from the study, "HPLC Analysis of Catechins in Various Kinds of Green Teas Produced in Japan and Abroad," shows levels of catechins as a percentage of dry weight:
Saijo, Ryoyasu*, and Yoshiyuki Takeda**. "HPLC Analysis of Catechins in Various Kinds of Green Teas Produced in Japan and Abroad," Nippon Shokuhin Kagaku Kogaku Kaishi Vol. 46, No. 3. 138-47 (1999).
* Faculty of Education , Kagawa University, Saiwaicho 1-1, Takamatsu-shi Kagawa 760-8522
** Department of Tea Cultivation (Makurazaki) , NIVOT, Beppu 14041, Makurazaki-shi Kagoshima 898-0032
Interestingly, another study, "Contents of Individual Tea Catechins and Caffeine in Japanese Green Tea", shows very different percentage levels, though this study examines many more samples of green teas from Japan (85 samples total of various types of teas). Here again, though, matcha has less than other green teas except hojicha.
From top to bottom: Gyokuro high quality, gyokuro low quality, gyokuro average; Matcha high quality, matcha medium quality, matcha low quality, matcha average; Sencha high quality, sencha medium quality, sencha low quality, sencha average; bancha, hojicha, pan-fired tamaryokucha high, medium, low, average; steamed tamaryokucha high, medium, low, average.
First column of numbers lists the number of samples. Second-to-last lists the total catechins, the final column lists caffeine.
Goto, Testuhisa, Hitoshi Nagashima, Yuko Yoshida, and Masaaki Kiso. "Contents of Individual Tea Catechins and Caffeine in Japanese Green Tea," Chagyo Kenkyu Hokoku (Tea Research Journal) Vol. 1996 (1996) No. 83. 21-28.
Testuhisa Goto and Hitoshi Nagashima are from the National Food Research Institute. Yuko Yoshida and Masaaki Kiso are from the Tokyo Metropolitan Agricultural Experiment Station.
Finding a balance between health and flavor
The main thing to remember is that catechin is bitter tasting. The more bitter your tea is, the higher the amount of catechin. If you are sticking to tea leaves, then you'll find tea steeped in water above 80C/176F degree to be more bitter than the same tea leaf steeped below this level (try this with a shaded gyokuro or kabusecha!). 80C is the threshold where most of the catechin is extracted.
For powdered teas, some tea are quite good at limiting the bitterness despite consuming the entire leaf. Like matcha, because you would be consuming the entire leaf, you'll be able to get the highest amount of antioxidants into your body.