A long term study carried out in Japan has stumbled upon evidence that drinking green tea regularly could help to reduce the risk of dementia—one of the world’s most common degenerative memory conditions that usually affects the elderly.

13,645 men and women above the age of 65 and living in Ohsaki City took part in the long-term study which followed their health over the course of 6 years.

Starting in 2006, the participants were asked to fill in surveys about how much tea they consumed, in relation to other food items. They were also asked questions about their memory, mental health and motor function. At the end of the study in 2012, 8.7% of the overall group had developed dementia.

Encouragingly, it was found that the people who drank 3 to 4 cups of green tea a day had a 16% less risk of developing dementia than those who drank less than one cup a day. People who drank more than 5 cups of tea a day were found to have a 24% lower risk of the condition.

Even when the analysis of the study was limited to those who didn’t report memory problems, the results were still broadly the same. It is thought that the powerful natural antioxidant epigallocatechin gallate, or ECGC for short, that occurs in high amounts in green tea could be responsible for the reduce in risk.

Yasutake Tomata from Tohoku University, one of the scientists behind the study, is optimistic about the potential power of green tea to reduce a person’s risk of dementia. He commented: "This study has shown that green tea consumption is associated with a decreased risk of incident dementia in Japanese elderly individuals. This suggests that green tea consumption may have a preventive effect against dementia."