Green tea consumption is associated with annual changes in hippocampal volumes: A longitudinal study in community-dwelling middle-aged and older Japanese individuals

• Published in: Archives of gerontology and geriatrics 2021-09, Vol.96, p.104454-104454, Article 104454
• Main Authors: Zhang, Shu, Otsuka, Rei, Nishita, Yukiko, Nakamura, Akinori, Kato, Takashi, Iwata, Kaori, Tange, Chikako, Tomida, Makiko, Ando, Fujiko, Shimokata, Hiroshi, Arai, Hidenori
• Format: Article
• Language: English
• Subjects: Atrophy; Cohort; Gray matter; Green tea; Hippocampus; White matter
• ISSN: 0167-4943; 1872-6976
• DOI: 10.1016/j.archger.2021.104454

•A negative association between green tea consumption and brain atrophy has been suggested; however, this relationship has not yet been investigated in humans.•Aging leads to atrophy of gray matter, white matter, and the hippocampus over time.•Specifically, hippocampal atrophy plays an essential role in the progression of Alzheimer's disease and some non-Alzheimer's dementia disorders.•In this study, a negative association between green tea consumption and annual hippocampal atrophy was observed in community-dwelling middle-aged and older individuals. However, green tea consumption was not associated with annual changes in gray matter or white matter volumes.•The association of green tea consumption and reduced hippocampal atrophy was more evident among people aged 65 years and older and among women. To investigate the association between green tea consumption and the annual rate of change of gray matter (GM), white matter (WM), and hippocampal volumes in community-dwelling middle-aged and older Japanese individuals. A prospective cohort study with two years of follow-up was conducted as part of the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) project. A total of 1693 participants (862 men and 831 women, aged 40–89 years) were included. Green tea consumption (mL/day) data were collected with a 3-day dietary record. Volumes of GM, WM, and the hippocampus were estimated by T1-weighted brain magnetic resonance imaging and FreeSurfer software. The GM ratio, WM ratio, and hippocampal ratio (HR) were calculated as the percentages of total intracranial volume, respectively. The mean (SD) annual rate of change of hippocampal volume [(HR at baseline - HR at follow-up)/HR at baseline/follow-up years×100%] was 0.499 (1.128) (%). In the multivariable-adjusted general linear model, green tea consumption was negatively associated only with the annual rate of change of hippocampal volume (%) [β (95% CI) for each 1 mL/day increase in green tea consumption = -20.2E-5 (-35.0E-5 to -5.3E-5); P-value = 0.008]. No associations were observed for the annual rate of change of GM or WM volumes. The results remained significant when the analysis was limited to those with stable green tea consumption and were especially evident among individuals aged 65 years and older and among women. In this study, higher green tea consumption was associated with less annual hippocampal atrophy, and each additional 100 mL/day of green tea intake was related to a