Effects of Green Tea Consumption on Homocysteine Metabolism and Cognitive Dysfunction

Effects of Green Tea Consumption on Homocysteine Metabolism and Cognitive Dysfunction in Elderly: An Exploratory Clinical Study

Green tea contains catechins and theanine as major ingredients and has been reported to have various beneficial influences on human health. It is reported that the drinking green tea is inversely associated with serum homocysteine level in elderly. However the effect of green tea consumption on cognitive dysfunction is not clinically clarified. The purpose of this study is to investigate the effects of green tea consumption on homocysteine metabolism and cognitive dysfunction in elderly with impaired cognitive function.

Study Overview

• Status: Completed
• Conditions: Cognitive Impairment
• Intervention / Treatment: Dietary supplement: green tea powder

Detailed Description

Elderly people with impaired cognitive function go on increasing year by year with the coming aged society. Among them, the Alzheimer disease is a major cause of the illness, which is progressively worse, has no fundamental curable therapy, and induces the burdens of caregivers as well as the health insurance and national budget. Recently, homocysteine metabolism is reported to be related to atherosclerosis in aging, and draw attention as the etiology of cognitive dysfunction in elderly.

Green tea contains catechins and theanine as main ingredients. These components are reported to have anti-atherogenic action and effect on improving cognitive dysfunction. However, clinical evidence for homocysteine metabolism and cognitive dysfunction has not been clarified. Therefore, in this study, the investigators attempted to investigate the effects of green tea consumption on homocysteine metabolism and cognitive dysfunction in elderly with impaired cognitive function.

• Study Type: Interventional
• Enrollment (Anticipated): 15
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Japan
  • Tokyo
    • Higashimurayama, Tokyo, Japan, 189-0021
      • White Cross Nursing Home

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 48 years to 93 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Obtained written informed consent before participation
• Possible to consume green tea powder
• Possessing cognitive dysfunction; MMSE score less than 30
• Possible not to take any supplement possessing anti-oxidizing effect; i.e., vitamin A, C, E, β-carotene

Exclusion Criteria:

• Possessing allergy to green tea
• Possessing severe cardiac, respiratory, renal, or hepatic dysfunction
• Possessing severe anemia
• Diagnosed as inadequate to participate in the study by doctor

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: green tea powder; Natural green tea powder	Dietary supplement: green tea powder; Consuming 2 g/day of green tea powder in three times divided for 3 months

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in the serum homocysteine levels	Changes in the serum homocysteine levels before and after the intervention	between baseline and 3 months after

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in serum lipid levels	Changes in serum lipid levels before and after the intervention	between baseline and 3 months after
Changes in serum folic acid levels	Changes in serum folic acid levels before and after the intervention	between baseline and 3 months after
Changes in mini mental state examination (MMSE) scores	Changes in mini mental state examination (MMSE) scores before and after the intervention	between baseline and 3 months after

Collaborators and Investigators

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

Study record dates

Study Major Dates

• Study Start: May 1, 2012
• Primary Completion (Actual): July 1, 2013
• Study Completion (Actual): July 1, 2013

Study Registration Dates

• First Submitted: May 1, 2012
• First Submitted That Met QC Criteria: May 6, 2012
• First Posted (Estimate): May 8, 2012

Study Record Updates

• Last Update Posted (Estimate): July 16, 2013
• Last Update Submitted That Met QC Criteria: July 14, 2013
• Last Verified: July 1, 2013

More Information

Terms related to this study

• Keywords: atherosclerosis; aging; cognitive impairment; green tea; homocysteine
• Additional Relevant MeSH Terms: Mental Disorders; Neurocognitive Disorders; Cognition Disorders; Cognitive Dysfunction
• Other Study ID Numbers: CT201201; 24220501 (Other Identifier: Ministry of Health, Labor and Welfare)