A study led by the Kanazawa University Graduate School of Medical Sciences has revealed a significant link between higher green tea consumption and fewer cerebral white matter lesions in older adults without dementia. The findings suggest that drinking three or more cups of green tea daily could help protect brain health, while coffee consumption showed no notable effect.
Green tea and coffee are both renowned for their neuroprotective properties and are the most commonly consumed beverages worldwide after water. Although previous research has indicated cognitive benefits from tea and coffee, few studies have explored their direct impact on brain structural changes in older adults.
Cerebral white matter lesions (WML), often associated with small vessel disease, are linked to cognitive decline, vascular dementia, and Alzheimer’s disease. This study aimed to assess the impact of green tea and coffee on white matter lesion volume, hippocampal volume, and total brain volume using MRI data.
The research, titled “Green tea consumption and cerebral white matter lesions in community-dwelling older adults without dementia,” was published in npj Science of Food and conducted as part of the Japan Prospective Studies Collaboration for Aging and Dementia. This large-scale, multisite observational study involved 8,766 participants aged 65 and older across eight research centers in Japan, with data collection taking place between 2016 and 2018.
Participants’ green tea and coffee consumption was measured using a Food Frequency Questionnaire, categorizing intake into four levels: 0–200 ml, 201–400 ml, 401–600 ml, and ≥601 ml. MRI scans provided data on WML volume, hippocampal volume (HV), and total brain volume (TBV). The study controlled for confounding factors such as demographics, health conditions, lifestyle habits, and genetic risk factors for Alzheimer’s disease.
The analysis found that higher green tea consumption was significantly linked to lower WML volumes. Participants who drank 600 ml of green tea daily had WML volumes that were 3% lower compared to those who consumed 200 ml or less, while those who drank 1,500 ml daily had WML volumes 6% lower than the reference group.
No significant associations were found between green tea intake and hippocampal or total brain volumes. Coffee consumption did not have a significant impact on WML volume, HV, or TBV.
The study also examined subgroups based on depression status and the presence of the ApoE ε4 allele, a genetic risk factor for Alzheimer’s disease. Significant reductions in WML volumes were observed only in individuals without depression or the ApoE ε4 allele.
The researchers suggest that the antioxidant and anti-inflammatory properties of green tea catechins, such as epigallocatechin gallate, may help reduce vascular damage and promote brain health, although further studies are needed to confirm specific components as causal factors.