Linked from
The 14 pages that link to Tea, each with the reason it gives.
CaffeineRelated: Tea supplies caffeine alongside other compounds, including L-theanine.
FlavonoidRelated: Tea contains abundant flavan-3-ols and their oxidation products.
MethylxanthineRelated: Tea supplies caffeine and smaller amounts of other methylxanthines.
TheophyllineRelated: Tea leaves contain small amounts of theophylline alongside much more caffeine.