A comprehensive new study suggests that drinking green tea could help protect aging brains, mainly by reducing specific brain lesions associated with cognitive decline and dementia. The research, published in NPJ Science of Food, analyzed data from over 8,700 older Japanese adults who did not have dementia.
The study, conducted by researchers across multiple Japanese institutions between 2016-2018, found that people who drank more green tea had fewer white matter lesions in their brains, even after accounting for other health and lifestyle factors. White matter lesions, which can be detected through brain imaging, are often considered a sign of brain aging and have been linked to increased risk of both vascular dementia and Alzheimer’s disease.
“The findings suggest that drinking green tea, especially three or more cups per day, may help prevent dementia by reducing these concerning brain changes,” says Dr. Moeko Noguchi-Shinohara, one of the study’s lead researchers from Kanazawa University.
The researchers used magnetic resonance imaging (MRI) to examine participants’ brains while collecting detailed information about their tea and coffee consumption habits. They found that participants who drank 600ml (about 3 cups) or more of green tea daily showed significantly fewer white matter lesions than those who consumed less. This protective effect increased with higher consumption – those drinking approximately 7-8 cups daily showed even greater benefits.
Interestingly, while green tea showed protective effects, coffee consumption did not demonstrate the same benefits. The researchers suggest this may be because green tea contains different beneficial compounds, including catechins with antioxidant and anti-inflammatory properties. Green tea also contains less caffeine than coffee, which could be relevant since caffeine can affect blood pressure.
The protective effects of green tea were particularly notable in people without depression and in those without a specific genetic risk factor for Alzheimer’s disease (known as APOE ε4). However, the researchers emphasize that more studies are needed to understand these relationships fully.
While these findings are promising, the researchers note some limitations of their work. The study was observational, meaning it cannot prove that green tea directly causes a reduction in brain lesions. Additionally, the research was conducted exclusively in Japan, where green tea consumption is common, so similar studies in other populations would be valuable to confirm these effects.
Still, given the growing global concern about dementia and brain aging, these results suggest that incorporating green tea into one’s daily routine could be a simple yet beneficial lifestyle choice for brain health, particularly in older adults. Individuals should always consult their healthcare providers about dietary changes, especially if they have specific health conditions or concerns.
