Green Tea Consumption and Brain White Matter Health in Older Adults

Age-related changes in the brain are a major contributor to cognitive decline and dementia. Among these changes, cerebral white matter lesions—often detected by magnetic resonance imaging (MRI)—are considered important markers of small vessel disease and are associated with impaired cognition, gait disturbances, and increased dementia risk. Dietary factors have increasingly been investigated as potentially modifiable influences on brain aging. In this context, a large cross-sectional study from Japan provides new population-level evidence linking green tea consumption to better white matter health in older adults.

The analysis was conducted as part of the Japan Prospective Studies Collaboration for Aging and Dementia (JPSC-AD) and published in January 2025 in npj Science of Food. The study included 8,766 community-dwelling Japanese adults aged 65 years or older who were free of dementia at the time of assessment. By focusing on a cognitively intact elderly population, the researchers aimed to examine early structural brain changes that may precede clinical cognitive decline. Dietary intake was assessed through standardized questionnaires, while brain structure was evaluated using MRI, allowing for objective measurement of white matter lesion volume.

The results demonstrated a clear inverse association between green tea intake and cerebral white matter lesion burden. Compared with individuals who consumed approximately 200 ml per day (around one cup), participants who drank at least 600 ml per day (about three cups) exhibited roughly a 3% lower volume of white matter lesions. Those with very high intake—approximately 1,500 ml per day (seven to eight cups)—showed an even greater reduction of about 6%. Importantly, these associations remained statistically significant after adjusting for major confounding factors, including age, sex, vascular risk factors, and lifestyle variables. This dose-dependent pattern strengthens the plausibility of a protective relationship between green tea consumption and white matter integrity.

Notably, the study found no significant associations between green tea intake and hippocampal volume or total brain volume. This suggests that green tea may exert its effects more specifically on cerebrovascular-related brain changes rather than on global brain atrophy or regions primarily associated with memory. In addition, coffee consumption was not associated with any of the MRI outcomes examined, highlighting a potential specificity of green tea among commonly consumed beverages.

Further subgroup analyses revealed important modifiers of the observed association. The protective relationship between green tea and white matter lesions was present only in participants without depression and those who did not carry the apolipoprotein E ε4 (ApoE ε4) allele, a well-established genetic risk factor for Alzheimer’s disease. These findings suggest that depression and genetic vulnerability may attenuate or override the beneficial effects of green tea on brain structure. From a biological perspective, this interaction is plausible, as both depression and ApoE ε4 are linked to increased neuroinflammation, vascular dysfunction, and oxidative stress—pathways that may limit the neuroprotective potential of dietary polyphenols.

Green tea is rich in bioactive compounds such as catechins, particularly epigallocatechin gallate (EGCG), which have antioxidant, anti-inflammatory, and endothelial-protective properties. These mechanisms are consistent with a reduction in small vessel–related brain damage, offering a plausible explanation for the observed association with lower white matter lesion burden. However, the cross-sectional design of the study precludes causal inference, and reverse causation or residual confounding cannot be entirely excluded.

In conclusion, this large population-based analysis published in npj Science of Food provides robust evidence that higher green tea consumption is associated with fewer cerebral white matter lesions in older adults without dementia (npj Science of Food, 2025). While the findings do not establish causality, they support the hypothesis that green tea may contribute to healthier brain aging, particularly in individuals without depression or high genetic risk for dementia. Longitudinal studies and intervention trials will be essential to determine whether increasing green tea intake can actively slow cerebrovascular brain aging and reduce future dementia risk.