A research team from Kanazawa University in Japan published a study in Nature. The study surveyed almost 9,000 adults over age 65 and used MRI scans to measure cerebral white matter lesions. Researchers found that elderly individuals who regularly consumed green tea had fewer white matter lesions, which serve as indicators of reduced brain blood flow and risk factors for brain infarction and dementia.
The investigation revealed that drinking about 600 ml (approximately three cups) of green tea daily correlated with a lower volume of white matter lesions. One segment of the study showed that participants who drank three or more cups each day had 3 percent fewer lesions than those who consumed one cup. The research also suggested that drinking more than three cups a day might help prevent dementia, a finding that echoed earlier studies linking green tea with reduced risks of Alzheimer’s disease and cognitive decline.
The team categorized daily beverage intake into four volume groups—0–200 ml, 201–400 ml, 401–600 ml, and more than 601 ml—with one cup equaling roughly 200 ml. Analysis of the MRI data demonstrated that participants who consumed around 600 ml of green tea per day displayed lower white matter lesion volumes than those who drank less than 200 ml. In contrast, the study did not find evidence that coffee consumption prevented cognitive decline. “A significant correlation was found between the reduction of brain white matter lesions in elderly people without dementia and increased green tea consumption,” said the research team. “No correlation was found with coffee consumption.”
Other investigations showed that drinking two to four cups of green tea daily lowered the risk of stroke by up to 24 percent. A meta-analysis in 2022 indicated that each cup of green tea reduced the risk of dementia by 6 percent, and another study found that long-term consumption of two to three cups per day lowered the risk of cognitive decline. However, the protective effects were absent among individuals with the APOE e4 variant or those who experienced depression, and the study did not reveal any association between green tea intake and the overall volumes of the hippocampus or the brain.
Green tea contained antioxidants such as catechins, with epigallocatechin gallate as a primary component. Epigallocatechin gallate was known for its anti-inflammatory properties and its ability to protect cells, potentially reducing vascular damage in the brain. These antioxidant and anti-inflammatory properties may explain why green tea consumption was linked with improved heart health, including lower cholesterol levels and reduced blood pressure—a factor associated with the development of white matter lesions.
The article was written with the assistance of a news analysis system.