Gargling With Green Tea for Prophylaxis of Influenza Infection in Teenagers

Effects of Gargling With Green Tea on Preventing Influenza Infection Among High School Students: A Randomized Clinical Study

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.

Study Overview

• Status: Unknown
• Conditions: Influenza Infection
• Intervention / Treatment: Dietary supplement: green tea

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.

• Study Type: Interventional
• Enrollment (Anticipated): 640
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Hiroshi Yamada, MD, PhD; Phone Number: +81-54-264-5762; Email: hyamada@u-shizuoka-ken.ac.jp
• Study Contact Backup: Name: Keiji Matsumoto, Ms; Phone Number: +81-54-264-5770; Email: d10902@u-shizuoka-ken.ac.jp

Study Locations

• Japan
  • Shizuoka, Japan
    • Recruiting
    • University of Shizuoka
    • Contact: Hiroshi Yamada, MD, PhD; Phone Number: +81-54-264-5762; Email: hyamada@u-shizuoka-ken.ac.jp
    • Contact: Keiji Matsumoto, Ms; Phone Number: +81-54-264-5770; Email: d10902@u-shizuoka-ken.ac.jp
    • Principal Investigator: Hiroshi Yamada, MD, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 13 years to 18 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Green tea; Gargling with green tea	Dietary supplement: green tea; Gargling three times daily for 90 days
Active Comparator: water; Gargling with water	Dietary supplement: green tea; Gargling three times daily for 90 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
the incidence rates of influenza infection	Until 3 months gargling

Secondary Outcome Measures

Outcome Measure	Time Frame
severity of influenza symptoms	until 3 months gargling
influenza-free time during the study period	until 3 months gargling
incidence of complications	until 3 months gargling
incidence rates of upper respiratory tract infections	until 3 months gargling
incidence of days of absence from school	until 3 months gargling
occurrence of the adverse events	until 3 months gargling

Collaborators and Investigators

• Sponsor: University of Shizuoka
• Investigators: Study Chair: Hiroshi Yamada, MD, PhD, University of Shizuoka

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start: November 1, 2010
• Primary Completion (Anticipated): April 1, 2014
• Study Completion (Anticipated): August 1, 2014

Study Registration Dates

• First Submitted: October 19, 2010
• First Submitted That Met QC Criteria: October 20, 2010
• First Posted (Estimate): October 21, 2010

Study Record Updates

• Last Update Posted (Estimate): February 15, 2013
• Last Update Submitted That Met QC Criteria: February 12, 2013
• Last Verified: February 1, 2013

More Information

Terms related to this study

• Keywords: influenza; prophylaxis; Respiratory Tract Infections; gargling; green tea; high school students
• Additional Relevant MeSH Terms: Pathologic Processes; RNA Virus Infections; Virus Diseases; Respiratory Tract Infections; Respiratory Tract Diseases; Disease Attributes; Orthomyxoviridae Infections; Infections; Communicable Diseases; Influenza, Human
• Other Study ID Numbers: CT2010001