With interest in tea and its constituents predominantly focusing on the polyphenol content in tea leaves, Kyoji Yoshino, from Numazu National College of Technology (Japan), and colleagues studied theaflavins, a compound found in high concentrations in black tea.  The team employed a mouse model of type IV allergy, which directly involves the immune system’s T-cells rather than an antibody reaction, whereby exposure to an allergen is thought to trigger the release of pro-inflammatory cytokines by type 1 T helper (Th1) cells. When the mice were fed theaflavins from black tea, the researchers observed the cytokine response was averted, with fewer inflammatory compounds produced and antioxidant levels in the blood maintained.  The team concludes that: “These results suggest that the theaflavins as well as catechins contribute to the anti-allergic effects of black tea.”