The Effect of Matcha Green Tea on Cognitive Function and Sleep Quality in Older Adults with Cognitive Decline

by | Nov 12, 2024 | 2024, Antioxidants, Brain Health, Cognitive Health, Sleep

Written by Harold Oster, MD. Results suggest that matcha green tea may have beneficial effects on social acuity and sleep quality in older adults with cognitive decline.

matcha teaDementia is an acquired loss of cognition across multiple domains, severely affecting social and occupational function. It is estimated that 50 million people worldwide are living with dementia, and that number is expected to increase. Risk factors for dementia include poor sleep quality1, lack of exercise, poor nutrition, and the apolipoprotein E (apoE) gene2. Matcha green tea contains high levels of antioxidants, including catechins, which may provide cognitive benefits. Theanine, responsible for the umami taste of matcha tea, may benefit sleep quality3.

Kazuhiko Uchida et al. studied the benefits of matcha tea in improving sleep quality and slowing cognitive decline in older adults. The authors recruited community-dwelling adults between sixty and eighty-five with mild cognitive impairment (MCI) or subjective cognitive decline. MCI is defined as scoring below normal on neurocognitive testing but not meeting the criteria for dementia2. The authors defined subjective cognitive decline as having complaints of forgetfulness without meeting the criteria for MCI or dementia. The authors randomized participants into intervention and placebo groups. The intervention group received nine capsules of matcha powder to take daily for twelve months. The total daily dose contained 170.8 mg of catechins, 48.1 mg of theanine, and 66.2 mg of caffeine. Neurocognitive tests were performed at baseline, six months, and the end of the twelve-month intervention. Multiple tests were performed, including the mini-mental state examination4 and Central Nervous System Vital Signs (CNSVS), which is a battery of seven neurocognitive tests across multiple domains5. Sleep quality was assessed with the Pittsburgh Sleep Quality Index6. Amyloid PET scans, sometimes used for diagnosing dementia7, were performed at baseline and twelve months in twelve participants in each group. Brain MRIs to detect hippocampal atrophy were performed at baseline and twelve months8. The data was adjusted for age, sex, and apoE genotype.

The authors noted the following:

  • Based on exclusion criteria, 99 participants completed the study.
  • No significant differences were noted between the groups at baseline.
  • Compared to baseline, the social acuity score in the CNSVS test improved in the intervention group. (p=0.028) Social acuity refers to the ability to perceive the psychological or emotional state of others. There was no change in social acuity in the placebo group.
  • No changes were noted in the other neurocognitive tests in either group.
  • There was a trend toward improvement in sleep quality in the matcha group. (p=0.088). There was no change in the placebo group.
  • There was no change in neuroimaging tests in either group.

Results suggest that matcha tea intake may have beneficial effects on social acuity and quality of sleep. The study’s limitations include a small sample size and possible residual confounding.

Source: Uchida, Kazuhiko, Kohji Meno, Tatsumi Korenaga, Shan Liu, Hideaki Suzuki, Yoshitake Baba, Chika Tagata et al. “Effect of matcha green tea on cognitive functions and sleep quality in older adults with cognitive decline: A randomized controlled study over 12 months.” Plos one 19, no. 8 (2024): e0309287.

© 2024 Uchida et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original
author and source are credited.

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Posted November 12, 2024.

Harold Oster, MD graduated from medical school in Miami, Florida in 1992 and moved to Minnesota in 2004. After more than 25 years of practicing Internal Medicine, he recently retired. Dr. Oster is especially interested in nutrition, weight management, and disease prevention. Visit his website at haroldoster.com.

References:

  1. Shi L, Chen SJ, Ma MY, et al. Sleep disturbances increase the risk of dementia: A systematic review and meta-analysis. Sleep Med Rev. Aug 2018;40:4-16. doi:10.1016/j.smrv.2017.06.010
  2. Arvanitakis Z, Shah RC, Bennett DA. Diagnosis and Management of Dementia: Review. Jama. Oct 22 2019;322(16):1589-1599. doi:10.1001/jama.2019.4782
  3. Sakurai K, Shen C, Ezaki Y, et al. Effects of Matcha Green Tea Powder on Cognitive Functions of Community-Dwelling Elderly Individuals. Nutrients. Nov 26 2020;12(12)doi:10.3390/nu12123639
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  6. Buysse DJ, Reynolds CF, 3rd, Monk TH, Hoch CC, Yeager AL, Kupfer DJ. Quantification of subjective sleep quality in healthy elderly men and women using the Pittsburgh Sleep Quality Index (PSQI). Sleep. Aug 1991;14(4):331-8.
  7. Pemberton HG, Collij LE, Heeman F, et al. Quantification of amyloid PET for future clinical use: a state-of-the-art review. Eur J Nucl Med Mol Imaging. Aug 2022;49(10):3508-3528. doi:10.1007/s00259-022-05784-y
  8. Huang L, Chen K, Hu X, Guo Q. Differential Atrophy in the Hippocampal Subfield Volumes in Four Types of Mild Dementia. Front Neurosci. 2020;14:699. doi:10.3389/fnins.2020.00699

 

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