Areca catechu is one of the four southern medicines in China. Hainan province is the main producing area of betel nut in China, and winter is the harvest season of betel nut. There are stalls selling betel nuts in the streets of Wanning, Lingshui, Ding 'an and other counties and cities in the main producing areas. Apart from enjoying the natural scenery of Bao Dao, visitors to Hainan also have many charming customs and feelings, among which "visiting betel nuts" is one. According to local introductions and ancient records, there has been a long-standing custom of betel nut hospitality in Hainan. As early as "Southern Vegetation-Betel Nut", it was recorded that "if you make friends with people who are more expensive than tourists, you must present this fruit first". Southern Vegetation was a rice crop in the Jin Dynasty, and it was written in 304. It is the earliest botanical monograph in China. During the Song Dynasty, the outside of the ridge replied, "The guest has no tea, but only takes betel nut as a gift." Hainan people have always regarded betel nut as a superior gift, and think that "associating with non-betel nut is not a gift to relatives, friends and guests". More than 800 years ago, Su Dongpo, who was exiled to Hainan Island, described a girl in the Li family with betel nuts and jasmine flowers in her mouth. It can be seen that the custom that Hainan people love eat areca, grow betel nuts and eat areca has been widely spread. Today, Li compatriots in Wanning, Lingshui and Wuzhishan still regard betel nut as a symbol of beauty and friendship. When guests come to the door, the host holds out betel nuts to entertain them first. Even people who can't chew betel nut should take a bite in return. On holidays, every household has betel nuts to worship the VIPs and relatives of the New Year. Eat areca and Hainan are very particular. Slice betel nut first, then grind it into powder with seasoning (make it into paste with shell powder), and roll it up with betel nut leaves. Then put it in your mouth and chew it slowly. It tasted astringent at first, with green water. After spitting out green water, it gave birth to Tenzin. After eating it, it was red and dizzy, just like being drunk. Just like Su Dongpo's improvisation, "Two blushes are charming, and Nong is drunk betel nut". Betel nut is also a symbol of young people's love. Once a young man takes a fancy to a girl, he first presents betel nut (commonly known as betel nut) to the woman's home to show his intention of proposing marriage. If the woman accepts, it means that she is engaged. Betel nut is an essential product when holding a wedding. The bride and groom should present betel nuts to relatives and friends who come to congratulate them as a token of their respect. But not much eat areca. There are many benefits, which can promote digestion, cure diseases and beautify. But! ! ! ! ! ! ! ! Attention! ! ! ! ! ! ! The World Health Organization Cancer Research Center recently warned the international community that chewing betel nut or betel nut will cause cancer. The World Health Organization Cancer Research Center pointed out that betel nut containing tobacco can cause oral cancer, pharyngeal cancer and esophageal cancer, while betel nut without tobacco can also cause oral cancer. Areca nut contained in various areca nut products can cause a precancerous lesion of oral cavity (oral submucosal fibrosis), which may turn into cancer at any time. It is reported that there are 390,000 cases of oral cancer (oral cancer or pharyngeal cancer) in the world every year, including 228,000 cases in South Asia and Southeast Asia, accounting for 58%. Most residents in these areas have the custom of chewing betel nut or betel nut. In ancient times, extended families often visited eat areca. It has the effect of removing bad breath. Nowadays, chewing gum and mouthwash tablets are all betel nuts. Betel nut, the common name of betel nut, is Latin from Malaysia and its name is catechu. In addition to southern China, India, Ceylon, Viet Nam, Malaysia, the Philippines and other places, the custom of chewing betel nut has lasted for at least 2000 years, which is the common hobby of civilians and nobles. "Betel nut" can be found in the literature, which can be traced back to the Southern and Northern Dynasties 1000 years ago. Areca catechu has the following functions in Ami society: entertaining visitors; Sacrifice in various ceremonies; Remuneration when asking relatives, friends or neighbors for help; An indispensable gift for engagement and marriage; A symbol of love; Compensation for violation of regulations. In the eyes of Ami people, betel nut (green baby) is not only food, but also symbolic: green baby has water in it, which tastes sweet like mother's milk, so green baby looks like mother. Secondly, the name of icep in Ami dialect is the same as that of female genitalia. Yamei is called eat areca, with a green boy as the symbol of the girl and a cane as the boy. White ash indicates love or affection, so if a young man sees a girl he knows planting betel nuts and rattan in his dream, it means that he is predestined friends with her. When a woman is pregnant, her husband dreams that he is planting rattan, which indicates that he will have a son. Dreaming of planting betel nut trees is a sign of having a daughter. In paiwan, betel nuts surround their homes, because betel nuts have a great weight in their lives. Betel nut is not only an essential food for socializing and entertainment, but also an indispensable gift for weddings. In the past, betel nuts planted by civilians in paiwan were the first to be given to leaders as a symbol of paying government rent. In the past, betel nut and ramie were essential crops in the fields of Lukai people. The family described the noble lady with a slender betel nut tree. In the life of people in the north and south, in addition to eating, sacrifices and witchcraft are also used. Betel nut is an irreplaceable object in the sea sacrifice, the pure land sacrifice and the realm exorcism sacrifice of the northern and southern nationalities. Beads, iron pots, banana leaves, etc. When practicing witchcraft, betel nut is the most commonly used wizard's article. The trunk of betel nut is not only used as fruit, but also an important building material for columns and trusses in the early years. In addition, the growing points and flower buds of betel nut trees, commonly known as half-day bamboo shoots, are rare delicacies. Lian Heng's book "Ya Yan": "Half a day's bamboo shoots, betel nuts also. The stem is two or three feet high, the leaves are like phoenix tails, swaying in the air and being destroyed by the wind. Taking the heart of the leaf and cutting the meat is especially sweet and crisp than bamboo shoots ... so it is difficult to help the trees and it is not easy to taste this strange taste. " Areca leaf sheath is a good material used as tableware by all ethnic groups. Fixed at both ends, made into a boat by bamboo branches, used to hold soup. Women send snacks and meals to their families who are working in the fields, as long as they carry soup and rice wrapped in bamboo tubes with them and pour them into the "betel nut boat" in the fields. Besides social and material functions, betel nut is the most important medical function. Li Shizhen, the author of Compendium of Materia Medica, said: "There are four advantages for Lingnan people to use betel nut instead of tea to prevent diseases. One said: sober up can make you drunk, and your cheeks will turn red if you cover your food for a long time. If you drink alcohol, Su Dongpo's so-called red tide will make you drunk on your cheeks. Second, drunkenness can sober him up. Chew it after drinking, and the phlegm will disappear, and the rest will disappear. Zhu Huian's so-called betel nut harvest is to remove phlegm. Three words: Hunger can make you full. Eating on an empty stomach will make you feel full, and eating when you are full will soon disappear. In all kinds of Chinese medicine books, it will be mentioned that betel nut is a blind choice of Chinese medicine, called "big belly", which has the effects of expelling worms, invigorating stomach, eliminating furuncle and stopping dysentery. Zheng Huiwen, Ph.D. in Pharmacy, University of California, pointed out in the British Journal of Psychology that chewing betel nut can help patients with schizophrenia to relieve their illness. According to the gene analysis of schizophrenic families in Pacific Island, it is found that the mutation of the second chromosome is related to the onset of schizophrenia. The researchers analyzed the reaction of 70 patients to chewing betel nut, and found that when chewing more than 10 tablets a day, the symptoms were less intense and more comfortable than those who were not in eat areca. Because betel nut contains arecoline, its influence on human body is similar to acetylcholine. This substance can reduce dopamine in the brain and achieve the therapeutic purpose similar to schizophrenia drugs. Dr Mary Lin, a doctor from Ma Kai, analyzed the white blood cell antigen (HLA) of people's families in Taiwan Province Province, and published "Inferring the Origin of Minnan People and Hakkas from Tissue Antigens" in international medical journals. It was found that Minnan Hakkas, commonly known as Taiwan Province people, belonged to the "Yue people" of South Asian race. The location of the Yue nationality is also the hub of the betel nut cultural circle. Vietnamese can also buy betel nuts in religious gift shops, because green seeds are one of the important sacrifices. Some gods only need young ones, some need young ones, and some need betel nuts to offer sacrifices. Betel nut is also an important food for Vietnamese weddings, in which young people's skin is carved and cut into six pieces, and a pile of leaves and vines are placed on plates to entertain guests. The connection between Yue people, Taiwan Province people and betel nut culture makes the proportion of people who love eat areca in Taiwan Province Province remain high. It seems that the relationship between tissue antigen and betel nut culture may be a subject worthy of in-depth study.