Theaflavins

Polyphenols

The russet pigments of black tea: they are born from the oxidation of the green leaf's catechins.

It is the only molecule that truly separates black tea from green tea. Both carry flavanols, but black has traded part of its own for these during oxidation — same leaf, two chemistries.

Effects and benefits

The russet pigments of black tea are born when the green leaf is left to oxidize. Too large to be absorbed, they stay in the gut, where the microbiota cuts them up; and two to four cups a day made arteries more flexible in trials.

For black tea, the leaves are rolled and left to oxidize: catechins pair up into theaflavins, orange, then into thearubigins, brown. That gives the color and the astringency.

In a controlled trial, black tea improved artery dilation in proportion to the dose, from one to two cups a day, and lowered blood pressure slightly (Grassi et al., 2016).

Drunk with a meal, tea curbs the absorption of iron from plants (see tannins): when you eat little meat, it is better drunk between meals.

Sources: Grassi et al., Eur J Nutr, 2016

Where to find it (2)

• Black tea
• Pu-erh tea