PP233-MON EFFECTS OF GREEN TEA COMPONENTS ON PREVENTING UPPER RESPIRATORY TRACT INFECTION IN ADULTS: A RANDOMIZED CONTROLLED TRIAL
Author: K. Matsumoto and H. Yamada and N. Takuma and H. Niino and Y.M. Sagesaka
Rationale: Experimental studies have revealed that green tea components prevent upper respiratory tract infection from some pathogens including inﬂuenza virus, while the clinical evidence has been inconclusive. This study was conducted to determine whether taking green tea catechins and theanine, which are major components of green tea, can prevent upper respiratory tract infection in adults. Methods:A randomized, double-blind, placebo-controlled trial of 200 adult workers conducted for 5 months from November, 2009 to April, 2010 in three healthcare facil- ities in Higashimurayama, Japan. The catechin/theanine group received capsules including green tea catechins (378mg/day) and theanine (210mg/day). The control group received placebo. The outcome was the incidence of upper respiratory tract infection including inﬂuenza infection. Trial registration: ClinicalTrials.gov Identiﬁer (NCT01008020) Results: Eligible adult workers (n = 197) were enrolled and randomly assigned to an intervention; 98 were allocated to receive catechin/theanine capsules and 99 to placebo. The incidence of upper respiratory tract infection was lower in the catechin/theanine group (46 participants; 47.4%) compared with the placebo group (59 participants; 59.6%), but this difference was not signiﬁcant (adjusted odds ratio, 0.63; 95% conﬁdence interval, 0.35 to 1.12; P = 0.116). Conclusion: Among healthcare adult workers, taking green tea catechins and theanine may be effective for the prophylaxis of upper respiratory tract infection.