Green tea may help prevent brain lesions in older adults

A study by researchers at Kanazawa University in Japan found that drinking green tea regularly may reduce certain types of brain damage in older adults who don’t have dementia.

The research focused on cerebral white matter lesions (WML), areas of brain damage often linked to aging, small blood vessel problems, and conditions like dementia and Alzheimer’s disease.

The study found that people who drank three or more glasses of green tea daily had fewer of these brain lesions, while drinking coffee did not show the same effect.

Green tea and coffee are among the most popular beverages in the world, second only to water. Both are known for containing compounds that may benefit the brain. Previous studies have suggested that drinking tea or coffee could improve memory and thinking skills.

However, little is known about how these drinks influence physical changes in the brain, especially in older people.

The study was part of a larger research project in Japan aimed at understanding aging and dementia. It looked at 8,766 adults aged 65 and older, all living in the community and free from dementia.

Participants answered detailed questions about their diets, including how much green tea and coffee they drank each day. Researchers then used MRI scans to measure the size of the white matter lesions in their brains, as well as the overall size of their brains and the hippocampus—a region crucial for memory.

The participants were grouped based on how much green tea they drank, ranging from less than one cup a day to over six cups.

After considering other factors like age, gender, health conditions, lifestyle habits, and genetic risks for Alzheimer’s disease, the researchers found a clear pattern: the more green tea people drank, the smaller their white matter lesions were.

For example, people who drank about three cups of green tea daily had 3% smaller WML volumes compared to those who drank less than one cup. For those who drank over six cups, the reduction was 6%.

However, green tea consumption did not seem to affect the size of the hippocampus or the overall brain volume. Meanwhile, coffee drinking had no significant impact on any of these brain measurements.

Interestingly, the study found that the benefits of green tea were strongest in people without depression or a specific genetic trait known as the ApoE ε4 allele, which increases the risk of Alzheimer’s disease. This suggests that green tea might work better for certain groups of people.

The researchers believe that compounds in green tea, especially catechins like epigallocatechin gallate (EGCG), may help protect the brain. These compounds are known for their strong antioxidant and anti-inflammatory effects, which could reduce damage to blood vessels in the brain.

However, the study did not directly test how these compounds work, so more research is needed to confirm this.

This study adds to the growing evidence that diet plays an important role in brain health, particularly as people age. For older adults looking to protect their brain, adding a few cups of green tea to their daily routine could be a simple and natural way to help maintain cognitive function.

However, it’s important to remember that green tea is not a cure-all, and a healthy lifestyle, including regular exercise and a balanced diet, remains essential.

Study Analysis and Review

The findings are compelling, showing a potential link between green tea and brain health. While the 3-6% reduction in WML volumes may seem small, it could have meaningful effects on reducing the risk of dementia over time.

The study’s strength lies in its large sample size and careful consideration of factors like genetics and mental health. However, it does have limitations.

The research relied on participants’ self-reported tea and coffee consumption, which can sometimes be inaccurate. Additionally, it only shows an association, not direct proof that green tea reduces brain lesions.

Overall, the study offers valuable insights and practical advice for aging adults. Future research could explore whether the benefits of green tea extend to preventing cognitive decline or whether other dietary factors play a role.

If you care about dementia, please read studies about how the Mediterranean diet could protect your brain health, and Vitamin B supplements could help reduce dementia risk.

For more information about brain health, please see recent studies that high-fiber diet could help lower the dementia risk, and these antioxidants could help reduce dementia risk.

The research findings can be found in npj Science of Food.