How switching your coffee for green tea may help prevent dementia

Independent

05-02-2025

While coffee is not without its health benefits, a recent Japanese study has found that green tea is superior for helping reduce the risk of dementia in older people.
The researchers looked at older people with coffee and tea drinking habits and found a 'significant association' between those who drank more green tea and lower cerebral white matter lesions - which are linked with vascular dementia and Alzheimer's disease.
The study published in NPJ Science of Food looked at the data of about 10,000 older Japanese people who were involved in an ongoing observational study on dementia. The participants had undergone MRI scans and filled out dietary surveys.
The researchers said high blood pressure (hypertension) was considered to be the 'most important risk factor' for those lesions, and green tea has been reported to reduce blood pressure.
Green tea also has less caffeine per cup than coffee, which may also help, the researchers said.
'Green tea consumption may contribute to white matter lesion reduction by improving blood pressure,' they added.
'Moreover, green tea contains less caffeine than coffee, which negatively affects blood pressure, thus suggesting that green tea may have a more beneficial impact on white matter lesions.'
A separate study recently found that drinking coffee in the morning could have more health benefits than drinking it throughout the day, including a reduced risk of heart disease and death.
Green tea is made from the leaves and buds of the Camellia Sinesis plant and contains antioxidants, vitamins and minerals as well as caffeine. A cup of green tea typically contains 25-45mg of caffeine.
Coffee, made from the seeds of a wide variety of coffee plants, also contains antioxidants. Depending on how it is brewed can contain about 100mg of caffeine.
The researchers stressed the study had limitations: 'First, we only investigated green tea and coffee intake when consumed as beverages and did not account for the amount contained in snacks.
'Importantly, there was also no information on how green tea was brewed, leading to potential variations in the content of bioactive substances.'
The researchers added the study only focused on the drinking habits of Japanese individuals, so it was not clear whether similar trends could be observed in other countries.
'In conclusion, this study revealed that increased green tea consumption was associated with reduced cerebral white matter lesions,' the researchers said.
'Given that cerebral white matter lesions are closely related to vascular dementia and AD, our findings indicate that drinking green tea, especially three or more glasses per day, may help prevent dementia.
'Nevertheless, further prospective longitudinal studies and basic research are needed to validate our results.'