Green tea consumption affects cognitive dysfunction in the elderly: a pilot study.

Kazuki Ide,Noriko Wakamiya,Junpei Nakase,Norikata Takuma,Hiroshi Yamada,Yuko Sagesaka,Mijong Park,Yuuichi Ukawa

doi:10.3390/nu6104032

Abstract

Green tea is known to have various health benefits for humans. However, the effect of green tea consumption on cognitive dysfunction remains to be clinically verified. We conducted a clinical study to investigate the effects of green tea consumption on cognitive dysfunction. Twelve elderly nursing home residents with cognitive dysfunction (Mini-Mental State Examination Japanese version (MMSE-J) score: <28) participated in the study (2 men, 10 women; mean age, 88 years). The participants consumed green tea powder 2 g/day for 3 months. After three months of green tea consumption, the participants’ MMSE-J scores were significantly improved (before, 15.3 ± 7.7; after, 17.0 ± 8.2; p = 0.03). This result suggests that green tea consumption may be effective in improving cognitive function or reducing the progression of cognitive dysfunction; however, long-term large-scale controlled studies are needed to further clarify the effect.

Highlights

In rapidly aging societies around the world, the number of patients with cognitive dysfunction, dementia, is gradually increasing [1]
SBP, Systolic blood pressure; DBP, Diastolic blood pressure; TC, total cholesterol; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; TG, Triglyceride; FPG, fasting plasma glucose; HbA1c: hemoglobin A1c. In this pilot study conducted to investigate the effect of green tea consumption on cognitive dysfunction and atherosclerotic risk factors in the elderly, we found that three months of green tea consumption improved cognitive dysfunction based on Mini-Mental State ExaminationJapanese version (MMSE-J) score changes
Domains, the short-term memory domain was especially improved. These results support the findings of previous epidemiological studies, and demonstrate that green tea improves cognitive function or reduces the progression of cognitive dysfunction even at the relatively low catechin and theanine concentrations that can be obtained from ordinary levels of daily green tea intake

Summary

Introduction

In rapidly aging societies around the world, the number of patients with cognitive dysfunction, dementia, is gradually increasing [1]. A number of experimental studies in vitro and in vivo have shown the neuroprotective effects of green tea and its components, such as catechins and theanine [8,9,10,11]. Anti-oxidative and anti-inflammatory effects of these components have been reported [10,11,12], and such effects may contribute to neuroprotection. Catechins have been reported to improve performance on cognition tests in rodent models of dementia, such as the Morris water maze, probe test, and passive avoidance test [10]. Theanine has been shown to attenuate memory impairment induced by amyloid protein, an Alzheimer’s disease trigger protein [9]

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Results

Discussion

Conclusion