Green tea Green tea is one of the types of tea composed entirely of leaves. It is also very popular in ancient times and originates from China. “Green tea has been used as a traditional medicine in areas such as China, Japan, India and Thailand to help control bleeding and help heal wounds, regulate body temperature, blood sugar and aid digestion.” (Green Tea) Green tea is good for the body. It is useful for long-term use, reducing the chances of heart disease, preventing HIV, decreasing the risks of esophageal cancer and also introduced for losing weight. While it has positive sides, it also comes with risks. Having a longer life is one of the good principles of drinking green tea. According to Dr. Emily Senay, “Japanese researchers conducted a study on 40,000 people between the ages of 40 and 79. They followed people for over 11 years and found that people who consumed five or more cups of green tea a day were 16 percent less likely to die from anything during that time than people who drank one cup a day . (Studies: Green tea can help prolong life) He meant that drinking green tea is very helpful in prolonging life and everyone should try drinking it. He believes that drinking green tea is one of the many procedures to have a longer life. Many people around the world would like to have a longer life because most of them want to achieve something or some of them would like to discover something. For example, engineers or kings who did good things towards their people wanted a long life to see if their hard work would make the land prosper. Meanwhile, from the perspective of an evil scientist or leader, they will wish for a longer life to spread their evil plans throughout the country and rule it. Reducing the chances of heart disease is also one of the benefits of drinking green tea. According to the "Book of Tea", written by the Zen priest Eisai in 1191, it describes how drinking green tea can have a positive effect on the five vital organs, in particular the heart. The book discusses the medicinal qualities of tea which include alleviating the effects of alcohol, stimulating action, curing blemishes, quenching thirst, eliminating indigestion, curing beriberi disease, preventing fatigue and improved urinary and brain function..