1997 Volume 71 Issue 6 Pages 487-494
We examined whether gargling with black tea prevents influenza infection. Tests were carried out during a five month period (October 1992 to March 1993). The control group that followed their normal daily routine, whereas the test group that gargled with 0.5 w/v% black tea extract twice daily (at 8 a.m. and 5 p.m.).
Influenza viruses were isolated from influenza patients and an antigen analysis was carried out. As a result, two strains of influenza A viruses (H3N2) and ten strains of B virus were detected.
An HI test was done using paired sera of the control group and the test group. The HI titers raised a four fold or greater in 48.8%(61/125) in the control group and 35.1%(35/134) in the test group. There was a significant difference (p <0.05) between the control and test groups.
These results indicate that black tea extract is effective as a prophylactic agent against influenza infection.
