The researchers conducted a questionnaire survey and cognitive ability test on 1003 elderly people over the age of 70 in a country  The results showed that the elderly who used to drink more than 2 cups of green tea a day were about half as likely to suffer cognitive impairment as the elderly who used to drink less than 3 cups of green tea a week, Regular drinking of fruit juice and coffee has no effect
In the survey, those who drank less than 3 cups of green tea a week preferred fruit juice and coffee
 Researchers believe that regular drinking of green tea may delay brain aging and reduce the risk of Alzheimer's disease