Polyphenol Content: Not All Teas are Created Equal
Comparison of the Catechins Composition of Fresh Tea Leaves by Their Plucking Positions in mg/gram of tea solution made by 1g of dried fresh leaves to 50 g of water (i.e. 2 g to 100 ml, as in the ISO Infusion Standard) Data obtained and simplified from Capillary Electrophoretic Determination of Theanine, Caffeine, and Catechins in Fresh Tea Leaves and Oolong Tea and Their Effects on Rat Neurosphere Adhesion and Migration, by C.N. Chen et al
Which products offer the most flavonoids?
Not all teas are created equal. Between a mass market product and a traditional whole leaf tea, there is a great discrepancy in flavonoid content, not to mention other things. According to the “USDA Database for the Flavonoid Content of Selected Foods” (5), for example, a bottled green tea contains a mean of 13 mg/100ml while a regular cup of freshly brewed tea can deliver over 133 mg/100ml. However, this “regular” cup of tea reflects only mean figures base on a huge range of products including those major brands of mass produced products (6) that are the fannings (i.e. tea dust) (7) in teabags. Catechins are unstable materials which composition can easily be altered through exposure to the environmental elements. The minute the leaf is broken to expose its content, they begin to change. Good packaging practice slows this down, but the more broken the leaves are the quicker they are to change.
Fresh green leaves: 2150 mg/100ml
And there is the quality of the leaves. In finer tea production, one shoot and the two immediate young leaves (8) form a pluck. This contrasts sharply with machine harvesting, where the hedge of tea bushes is uniformly cut down 2 inches. Leaves, together with twigs, fruits and flowers are shredded into the collection bags. In a study done in Taiwan (9) where the catechins contents of the various leaves by their twig tip position are evaluated, each of the youngest 3 leaves holds between 38 to 43 mg/g of flavonoids per gram of tea liquid (10), i.e. 1900~2150 mg per 100 ml. There will be some loss when the fresh leaves go through production, but between 18~90% of tea catechins can be dissoluble in normal tea-making (11), this is still a few hundred times that of the bottled tea, and a lot more than your 250 mg “green tea catechins” capsule!
Here is an insight: As listed in the USDA report, while some selections of loose leaf tea can be offering over 200 mg of EGCG alone in each 100 ml of tea liquor (made with 1 g of leaves to 100 ml of water), some other only 2.3 mg. Some instant tea mixes 0 mg and the same amount in over half of all the other flavonoids. They are the junk of beverages.
Fine teas: Much better value
If you need the health benefits of catechins, whole leaves, fresh green tea made from the youngest 3 leaves are what you should look for. Even if you are on a budget, there are a few grades, a large number of varieties from various origins with different pricing. Well, they maybe a little more than your generic “green tea” teabag, but let’s be objective, a cup of tea made from 2~3 gram of whole leaf green tea of reasonably fine quality costs no more than your discounted can of pop!
