Clinical trial NCT01225770: Gargling With Green Tea for Prophylaxis of Influenza Infection in Teenagers
Official title: Effects of Gargling With Green Tea on Preventing Influenza Infection Among High School Students: A Randomized Clinical Study
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE3
Conditions: Influenza Infection
Keywords: green tea
gargling
prophylaxis
influenza
Respiratory Tract Infections
high school students
Lead sponsor: University of Shizuoka
Sponsor class: OTHER
First posted: 2010-10-21
Enrollment: 640
Sex: ALL
Minimum age (years): 15
Maximum age (years): 20
Standard ages: CHILD
ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: Experimental and clinical studies in adults have reported that green tea catechins prevent influenza infection. In this clinical randomized study, the investigators aimed to determine the effects of gargling with green tea on the prophylaxis of influenza infection among high school teenagers.

Detailed description: Influenza infection is the principal cause of acute respiratory illnesses and occurs in epidemic or pandemic worldwide. It spreads easily among high school students and from them to the rest of the community; therefore the prevention of influenza is very important.

Experimental studies have revealed that some components of green tea can prevent influenza infection in vitro. In clinically, gargling with green tea catechins has been reported to have possibilities to preventing influenza infection in adults; however, little clinical evidence in teenagers has so far been existed. Based on this background, the investigators designed a randomized study to evaluate the clinical efficacy of gargling with green tea in preventing influenza infection among high school students.

Eligibility criteria: Inclusion Criteria:

* aged from 15 to 20 years
* obtained written informed consent from both the student and parent before participation
* possible to gargle during 90 days
* possible to fill in questionnaire

Exclusion Criteria:

* Possessing allergy to green tea
* Possessing history of influenza infection within 6 months before entering the study
* Possessing severe immune disease or whole body infection
* severe cardiac, respiratory, renal, or hepatic dysfunction
* diagnosed as inadequate to participate in the study by student doctor

Primary outcomes:
measure: the incidence rates of influenza infection
timeFrame: Until 3 months gargling
Secondary outcomes:
measure: severity of influenza symptoms
timeFrame: until 3 months gargling
measure: influenza-free time during the study period
timeFrame: until 3 months gargling
measure: incidence of complications
timeFrame: until 3 months gargling
measure: incidence rates of upper respiratory tract infections
timeFrame: until 3 months gargling
measure: incidence of days of absence from school
timeFrame: until 3 months gargling
measure: occurrence of the adverse events
timeFrame: until 3 months gargling
Other outcomes:
Locations:
city: Shizuoka
country: Japan
facility: University of Shizuoka
Study officials:
affiliation: University of Shizuoka
name: Hiroshi Yamada, MD, PhD
role: STUDY_CHAIR
References:
citation: Ide K, Yamada H, Matsushita K, Ito M, Nojiri K, Toyoizumi K, Matsumoto K, Sameshima Y. Effects of green tea gargling on the prevention of influenza infection in high school students: a randomized controlled study. PLoS One. 2014 May 16;9(5):e96373. doi: 10.1371/journal.pone.0096373. eCollection 2014.