Regular consumption of black tea increases circulating kynurenine concentrations: A randomized controlled trial

Conclusions Increased circulation of kynurenine and KYN/TRP following regular black tea consumption may indicate enhanced tryptophan breakdown, possibly due to increased activity of immune activation-induced tryptophan degrading enzyme indoleamine 2,3-dioxygenase. General significance The influence of black tea consumption on biomarkers of immune system activation could relate to its general health benefits. Data suggests that net effect strongly depend on the individual immune state, being stimulatory in healthy individuals while acting more immune dampening in situations with an inflammatory background.
Source: BBA Clinical - Category: Biochemistry Source Type: research