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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

Status
UNKNOWN
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01225770
Enrollment
640
Registered
2010-10-21
Start date
2010-11-30
Completion date
2014-08-31
Last updated
2013-02-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Influenza Infection

Keywords

green tea, gargling, prophylaxis, influenza, Respiratory Tract Infections, high school students

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.

Interventions

DIETARY_SUPPLEMENTgreen tea

Gargling three times daily for 90 days

Sponsors

University of Shizuoka
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
15 Years to 20 Years
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frame
the incidence rates of influenza infectionUntil 3 months gargling

Secondary

MeasureTime frame
influenza-free time during the study perioduntil 3 months gargling
incidence of complicationsuntil 3 months gargling
severity of influenza symptomsuntil 3 months gargling
incidence of days of absence from schooluntil 3 months gargling
occurrence of the adverse eventsuntil 3 months gargling
incidence rates of upper respiratory tract infectionsuntil 3 months gargling

Countries

Japan

Contacts

Primary ContactHiroshi Yamada, MD, PhD
hyamada@u-shizuoka-ken.ac.jp+81-54-264-5762
Backup ContactKeiji Matsumoto, MS
d10902@u-shizuoka-ken.ac.jp+81-54-264-5770

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 8, 2026