What's inside tea, and where does it go in your body?
Green, black and oolong tea come from the same plant. Contains catechins, a little caffeine and L-theanine.
Iron note
Tea polyphenols reduce non-heme iron absorption when drunk with meals.
Supplements
Concentrated green tea extract supplements have been linked to rare liver injury — different from drinking tea.
Evidence & sources
Green tea extract supplements have been linked to rare cases of liver injury; drinking green tea as a beverage is believed safe in moderate amounts. Evidence: moderate. Known: Case reports and regulatory reviews. Unknown: Mechanism and susceptibility unclear. Source: NIH NCCIH, Green Tea (Current revision).