Green tea and brain white matter lesions in research
A study led by Kanazawa University reported a significant association between higher green tea consumption and markedly reduced brain white matter lesions in older adults without dementia. The findings suggest that drinking three or more cups of green tea a day may help protect brain health, whereas coffee consumption showed no significant effect.
Research objectives and context
Green tea and coffee contain neuroprotective compounds and are the most widely consumed beverages globally after clean water. Previous studies show that drinking tea and coffee offers cognitive benefits; however, few studies have examined their direct association with brain structural changes in older adults.
Brain white matter lesions, a hallmark of small vessel disease, are associated with cognitive decline, vascular dementia, and Alzheimer's disease (AD). This study aimed to evaluate the impact of green tea and coffee consumption on white matter hyperintensity volume, hippocampal volume, and total brain volume using magnetic resonance imaging (MRI) data.
Dietary and MRI data
Study "Green tea consumption and cerebral white matter lesions in community-dwelling older adults without dementia", roughly translated as “Green tea consumption and the extent of cerebral white matter lesions in non-demented older adults", published in the journal npj Science of Food, conducted as part of the Japan Prospective Studies Collaboration for Aging and Dementia, a large-scale, multi-site observational study involving eight research centers across Japan.
Data was collected from 2016 to 2018, including dietary assessments, MRI scans, and cognitive evaluations of 8,766 participants aged 65 and older. A Food Frequency Questionnaire was used to measure daily consumption of green tea and coffee, categorized into four levels: 0–200 ml, 201–400 ml, 401–600 ml, and ≥601 ml.
Brain MRI scans provided data on white matter lesion volume (WML), hippocampal volume (HV), and total brain volume (TBV). Advanced statistical models were applied to adjust for confounding factors, including demographics, health status, lifestyle habits, and genetic risk factors for Alzheimer's disease.
The analysis excluded participants with mild cognitive impairment (MCI), dementia, or incomplete data, narrowing the final cohort down to 8,766 individuals.
Observed associations and differences between groups
After adjusting for confounding factors, higher green tea consumption was significantly associated with lower WML volume. Participants who consumed 600 ml of green tea daily had a 3% lower WML volume compared to those who consumed 200 ml or less, and those who consumed 1,500 ml daily had a 6% lower WML volume compared to the control group.
No significant association was observed between green tea consumption and total brain volume or hippocampal volume. Coffee consumption also did not significantly affect WML, HV, or TBV.
The study also examined subgroups based on depression status and the presence of the ApoE ε4 allele. A significant reduction in WML volume with increased green tea consumption was observed only in individuals without depression or the ApoE ε4 allele.
The findings suggest that the antioxidant and anti-inflammatory properties of catechins in green tea, such as epigallocatechin gallate, may reduce vascular damage and promote brain health.