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Effects of green tea consumption on cognitive dysfunction in an elderly population: a randomized placebo-controlled study
BACKGROUND: Green tea is a beverage with potential effects on cognitive dysfunction, as indicated by results of experimental studies. However, its effects in humans, especially at real-world (typical) consumption levels, are unclear. METHODS: A double-blind, randomized controlled study was conducted...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4855797/ https://www.ncbi.nlm.nih.gov/pubmed/27142448 http://dx.doi.org/10.1186/s12937-016-0168-7 |
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author | Ide, Kazuki Yamada, Hiroshi Takuma, Norikata Kawasaki, Yohei Harada, Shohei Nakase, Junpei Ukawa, Yuuichi Sagesaka, Yuko M. |
author_facet | Ide, Kazuki Yamada, Hiroshi Takuma, Norikata Kawasaki, Yohei Harada, Shohei Nakase, Junpei Ukawa, Yuuichi Sagesaka, Yuko M. |
author_sort | Ide, Kazuki |
collection | PubMed |
description | BACKGROUND: Green tea is a beverage with potential effects on cognitive dysfunction, as indicated by results of experimental studies. However, its effects in humans, especially at real-world (typical) consumption levels, are unclear. METHODS: A double-blind, randomized controlled study was conducted to assess the effects of green tea consumption on cognitive dysfunction (Mini-Mental State Examination Japanese version (MMSE-J) score <28) in Japan. Participants were randomly allocated to the green tea or placebo group, and consumed either 2 g/day of green tea powder (containing 220.2 mg of catechins) or placebo powder (containing 0.0 mg of catechins), respectively, for 12 months. Cognitive function assessments were performed every 3 months using the MMSE-J and laboratory tests. RESULTS: Thirty-three nursing home residents with cognitive dysfunction were enrolled (four men, 29 women; mean age ± SD, 84.8 ± 9.3; mean MMSE-J score ± SD, 15.8 ± 5.4), of whom 27 completed the study. Changes of MMSE-J score after 1 year of green tea consumption were not significantly different compared with that of the placebo group (−0.61 [−2.97, 1.74], least square mean (LSM) difference [95 % CI]; P = 0.59). However, levels of malondialdehyde-modified low-density lipoprotein (U/L), a marker of oxidative stress, was significantly lower in the green tea group (−22.93 [−44.13, −1.73], LSM difference [95 % CI]; P = 0.04). CONCLUSIONS: Our results suggest that 12 months green tea consumption may not significantly affect cognitive function assessed by MMSE-J, but prevent an increase of oxidative stress in the elderly population. Additional long-term controlled studies are needed to clarify the effects. TRIAL REGISTRATION: UMIN000011668 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12937-016-0168-7) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-4855797 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-48557972016-05-05 Effects of green tea consumption on cognitive dysfunction in an elderly population: a randomized placebo-controlled study Ide, Kazuki Yamada, Hiroshi Takuma, Norikata Kawasaki, Yohei Harada, Shohei Nakase, Junpei Ukawa, Yuuichi Sagesaka, Yuko M. Nutr J Research BACKGROUND: Green tea is a beverage with potential effects on cognitive dysfunction, as indicated by results of experimental studies. However, its effects in humans, especially at real-world (typical) consumption levels, are unclear. METHODS: A double-blind, randomized controlled study was conducted to assess the effects of green tea consumption on cognitive dysfunction (Mini-Mental State Examination Japanese version (MMSE-J) score <28) in Japan. Participants were randomly allocated to the green tea or placebo group, and consumed either 2 g/day of green tea powder (containing 220.2 mg of catechins) or placebo powder (containing 0.0 mg of catechins), respectively, for 12 months. Cognitive function assessments were performed every 3 months using the MMSE-J and laboratory tests. RESULTS: Thirty-three nursing home residents with cognitive dysfunction were enrolled (four men, 29 women; mean age ± SD, 84.8 ± 9.3; mean MMSE-J score ± SD, 15.8 ± 5.4), of whom 27 completed the study. Changes of MMSE-J score after 1 year of green tea consumption were not significantly different compared with that of the placebo group (−0.61 [−2.97, 1.74], least square mean (LSM) difference [95 % CI]; P = 0.59). However, levels of malondialdehyde-modified low-density lipoprotein (U/L), a marker of oxidative stress, was significantly lower in the green tea group (−22.93 [−44.13, −1.73], LSM difference [95 % CI]; P = 0.04). CONCLUSIONS: Our results suggest that 12 months green tea consumption may not significantly affect cognitive function assessed by MMSE-J, but prevent an increase of oxidative stress in the elderly population. Additional long-term controlled studies are needed to clarify the effects. TRIAL REGISTRATION: UMIN000011668 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12937-016-0168-7) contains supplementary material, which is available to authorized users. BioMed Central 2016-05-04 /pmc/articles/PMC4855797/ /pubmed/27142448 http://dx.doi.org/10.1186/s12937-016-0168-7 Text en © Ide et al. 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Ide, Kazuki Yamada, Hiroshi Takuma, Norikata Kawasaki, Yohei Harada, Shohei Nakase, Junpei Ukawa, Yuuichi Sagesaka, Yuko M. Effects of green tea consumption on cognitive dysfunction in an elderly population: a randomized placebo-controlled study |
title | Effects of green tea consumption on cognitive dysfunction in an elderly population: a randomized placebo-controlled study |
title_full | Effects of green tea consumption on cognitive dysfunction in an elderly population: a randomized placebo-controlled study |
title_fullStr | Effects of green tea consumption on cognitive dysfunction in an elderly population: a randomized placebo-controlled study |
title_full_unstemmed | Effects of green tea consumption on cognitive dysfunction in an elderly population: a randomized placebo-controlled study |
title_short | Effects of green tea consumption on cognitive dysfunction in an elderly population: a randomized placebo-controlled study |
title_sort | effects of green tea consumption on cognitive dysfunction in an elderly population: a randomized placebo-controlled study |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4855797/ https://www.ncbi.nlm.nih.gov/pubmed/27142448 http://dx.doi.org/10.1186/s12937-016-0168-7 |
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