Effects of Tea Catechin Consumption on the Prophylaxis of Influenza Infection

Not Applicable

Completed

• Conditions: Influenza Infection
• Interventions: Dietary Supplement: tea catechin extracts

• Registration Number: NCT01008020
• Lead Sponsor: Masahiro Morikawa

Brief Summary

The Purpose of this study is to evaluate the effects of 5 months catechin consumption on the prevention of influenza infection.

Detailed Description

Catechins are the major components of tea flavonoids and are reported to possess physiological activities such as antiviral effects. Recent experimental studies have revealed that tea catechin extracts prevent influenza infection, but few studies have been conducted on the clinical effects of tea catechin consumption on the prophylaxis of influenza infection. Based on these backgrounds, we designed a prospective randomized controlled study to evaluate the effects of 5 months tea catechin consumption on the prophylaxis of influenza infection.

Study Timeline

• Study First Submitted: 2009-10-29
• Study Start: 2009-11
• Study First Submitted QC: 2009-11-03
• Study First Posted: 2009-11-05
• Primary Completion: 2010-06
• Study Completion: 2010-10
• Status Verified: 2013-07
• Last Update Submitted: 2013-07-14
• Last Update Posted: 2013-07-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 200

Inclusion Criteria

• aged over 20 years
• possible to maintain without drinking tea more than 250 ml per day during the study
• possible to maintain without taking supplements or herbal products including catechin extracts during the study
• possible to fill out a questionnaire personally
• Obtained written informed consent before participation

Exclusion Criteria

• Possessing some chronic infectious diseases in need of therapy
• Possessing tea or catechin allergy
• Possessing a history of influenza infection before six months prior to the study
• diagnosed as inadequate for other reasons to participate the study by principal investigator

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Tea catechin extracts	tea catechin extracts	-

Primary Outcome Measures

Name	Time	Method
the incidence rates of influenza infection	Until 5 months consumption of the study capsules

Secondary Outcome Measures

Name	Time	Method
the incidence rates of upper respiratory tract infections	Until 5 months consumption of the study capsules
the severity of the symptoms and the duration of the cold among incident cases	Until 5 months consumption of the study capsules
occurrence of the adverse events	Until 5 months consumption of the study capsules

Trial Locations

Locations (1)

White Cross Nursing Home; 🇯🇵 Higashi Murayama, Tokyo, Japan