Yep, I'm still going on about the awesome power of green tea extract, but it really does deserve four posts! We've already looked at caffeine and proanthocyanins, and tomorrow we'll take a look at the other things found in green tea. Today - tannins and catechins!
Green tea extract is filled to the brim with polyphenolic goodness - up to 30% of the dry weight - so let's turn our attention to the flavonoids that make green tea so incredible!
Flavonoids behave as anti-oxidants on our skin and in our bodies by scavenging the free radicals produced at our cell membranes. It is thought (meaning there aren't enough studies or nothing conclusive) the flavonoids offer anti-inflammatory benefits by inhibiting pro-inflammation mediators in our bodies, such as prostaglandins.
Catechins are a type of flavonoid, also called condensed tannins, making up 10% to 18% of the polyphenols in green tea. (We also find hydrolyzable tannins like procyanidins, which we investigated yesterday.) They offer anti-oxidizing features - they have been shown to be more effective than BHT, which is incredibly effective - as well as anti-microbial and anti-fungal properties. There are 6 main catechins found in green tea, but the most exciting is epigallocatechin gallate (EGCg or EGCG), which is probably the most studied and the most active polyphenolic. (The others are catechin, gallocatechin, epicatechin, epigallcatechin, and epicatechingallate).
EGCg seems to be a wonder ingredient. It is an anti-inflammatory that provides protection from photo-damage. One study showed it could inhibit an essential bacterial enzyme by binding to it, thereby behaving as an anti-bacterial. Another, albeit small, study showed EGCg s effective against tooth decay! It is a very powerful anti-oxidant, up to 200 times more powerful than Vitamin E in in vitro studies.
As a note, tannins are very large molecules - if a catechin has 20 or more hydroxyl groups (-OH) groups, it's considered a tannin. Look at the size of that molecule!
Chlorogenic acid offers anti-oxidant, anti-viral, anti-fungal, and anti-bacterial benefits. Kaempferol is a very strong anti-oxidant and anti-inflammatory compound that can prevent oxidative damage on our skin. You might remember gallic acid from evening primrose, pomegranate, and mango posts - it is being studied as a burn and wound healer. Quercetin - also found in mango butter - is a powerful anti-oxidant. Rutin is both a powerful anti-oxidant and good anti-inflammatory ingredient. It is being studied for the treatment of varicose veins and other circulation issues, and it can prevent water retention.
Join me tomorrow to look at more awesomeness found in green tea before a few posts in using green tea extract in your creations!