It’s confirmed Who announced that aspartame may cause cancer.

  BEIJING, July 14 (Xinhua)-The World Health Organization (WHO) released relevant assessment results on the 14th local time in official website, and listed aspartame as a possible carcinogen, but added that it is safe to ingest aspartame if the daily intake does not exceed 40 mg per kilogram of body weight.

  Image source: WHO official website screenshot

  Francesco Blanca, Director of Nutrition and Food of WHO, introduced two evaluation results of aspartame research at a news conference, and said, "We are not suggesting that companies withdraw their products, nor are we suggesting that consumers stop using them completely. Just recommend moderate intake. "

  Recently, the controversy about "aspartame causing cancer" has aroused widespread concern. On 14th, WHO released a message in official website, and the Joint Expert Committee on Food Additives (JECFA) of the International Agency for Research on Cancer (IARC), the World Health Organization and the Food and Agriculture Organization of the United Nations (FAO) released the assessment results of aspartame’s health impact.

  According to WHO, aspartame is an artificial sweetener, which has been widely used in various foods and beverages since 1980s, including diet drinks, chewing gum, ice cream, dairy products (such as yogurt and breakfast cereal), toothpaste and medicines (such as cough drops).

  IARC cited "limited evidence" of human carcinogenicity, and classified aspartame as a possible carcinogen (IARC 2B group), while JECFA reiterated that the acceptable daily intake was 40mg/kg body weight.

  JECFA said that a person’s daily intake is safe within this limit. For example, if a person does not eat from other food sources, then an adult weighing 70 kilograms needs to consume more than 9-14 cans of sugar-free drinks containing 200 or 300 milligrams of aspartame every day to exceed the acceptable daily intake.

  "Cancer is one of the leading causes of death in the world, and one in six people dies of cancer every year." Blanca said that the evaluation of aspartame shows that although the safety is not the main problem of commonly used doses, its potential impact has been described and needs to be investigated through more and better studies.

  According to the news, IARC and JECFA conducted independent but complementary reviews to assess the potential carcinogenic hazards and other health risks related to the use of aspartame.

Investigation on college students’ eating habits: nearly 50% had overeating, and nearly 80% did not exercise after meals.

  China Youth Network, Beijing, October 11th After class at night, Wang Meng, a student of Changsha Medical College, received a WeChat from her mother, telling her to eat on time, eat less cold food and pay more attention to her health to avoid the recurrence of gastrointestinal diseases. In the past few days, the temperature has dropped in most parts of the country. Many parents are worried about the health of their children who are studying abroad, and tell them to add clothes, eat a reasonable diet and eat more hot meals. So, do college students insist on eating breakfast every day? Do you have the habit of overeating? Are you picky about food? Do you exercise after meals?

  Recently, China Youth Network Campus News Agency conducted a questionnaire survey on the topic of eating habits among 3,069 college students. The results show that nearly 50% of college students can’t insist on eating breakfast every day, nearly half of them have overeating, over 40% of them have the habit of being picky eaters, over 30% of them have the concept of "eat whatever they want", nearly 80% of them don’t exercise after meals, and nearly 40% of them have suffered from gastrointestinal diseases because of their eating habits.

The picture shows the proportion of college students eating breakfast. China Youth Network reporter Li Huaxi cartography

The picture shows the proportion of college students eating breakfast. China Youth Network reporter Li Huaxi cartography

  Nearly 50% of students can’t insist on eating breakfast every day, and nearly half have overeating.

  "I eat breakfast more often than ‘ Occasionally ’ Still low. " Chen Yang, a junior in xinxiang university, told the reporter that he had only eaten breakfast two or three times since the beginning of this semester, and his parents "pulled" him out of bed to eat, while at school, he hardly ate breakfast. The reasons for not eating breakfast are that the class time is tight and I want to sleep late, and I have not developed the habit of eating breakfast every day.

  In the survey, the reporter found that there are not a few college students who have similar experiences with Chen Yang, and 47.28% of the respondents said that they can’t insist on eating breakfast every day, and the main reasons for not eating breakfast are time constraints, sleeping late and loss of appetite, accounting for 67.45%, 49.27% and 35.48% respectively. In addition, 47.05% of the respondents said that they had bad eating habits such as overeating.

  Lin Wei studied in Guangdong University of Technology, and once had overeating when he finished the homework of the basic course of mechanical design. He recalled that at that time, he worked as a part-time tutor every night, and when he came back, he caught up with his homework. In many cases, he would do course design all night. At night, he would buy eggs, cakes, fried rice, pancake fruit, octopus balls, chicken rolls, bread and milk as supper, and mix them back and forth, eating three or four midnight snacks a night.

  "There are always times when I want to treat myself." After going to college, Lin Wei will overeat because of too many things, heavy tasks and great pressure. He will also overeat because of long-term intensive study and relaxation after work. Sometimes he will want to eat a lot of things for no reason.

The picture shows the proportion of college students' dietary concepts. China Youth Network reporter Li Huaxi cartography

The picture shows the proportion of college students’ dietary concepts. China Youth Network reporter Li Huaxi cartography

  Over 40% have the habit of partial eclipse and picky eaters, and over 30% mean "eat whatever you want"

  Wang Ying is a student of Zaozhuang College. She eats mainly staple food and vegetables every day and doesn’t like meat. In her daily diet, she will exclude most meat such as pork. "I like to eat vegetables and tomatoes. Only chicken and fish will eat a little bit of meat, and others can’t accept it." According to the survey data of China Youth Network Campus News Agency, 42.75% college students are picky eaters and partial eaters, and 34.47% college students’ dietary concept is "eat whatever they want".

  Li Hongwen, a student of Qingchuan College in Wuhan, is a typical "eat whatever you want". He said that when eating, he would only consider what he likes to eat. "I belong to the kind that I want to eat, and I can run all over the city for what I want to eat. For me, I eat what I want every day, and I am especially happy to think that I can eat delicious food after studying and working. " This makes him more motivated in his usual study and work.

The picture shows whether college students exercise after meals. China Youth Network reporter Li Huaxi cartography

The picture shows whether college students exercise after meals. China Youth Network reporter Li Huaxi cartography

  Nearly 80% do not exercise after meals, and nearly 40% of students have suffered from gastrointestinal diseases because of their eating habits.

  Wang Su, a student from Donghai College of Science and Technology, Zhejiang Ocean University, has no idea of exercising after meals. After meals, he often stays in the dormitory and is busy with his studies and work. "I am busy, I often have something temporary, and I don’t eat regularly. I don’t want to move when I am busy." He said that he knew the health benefits of exercise after meals, but "everyone was very busy, really didn’t have time, and he didn’t like exercise very much" became the reason why he gave up the idea of exercise after meals.

  The results of this survey show that 79.6% of the respondents, like Wang Su, "will not exercise after meals". In addition, 38.91% of the respondents had caused gastrointestinal diseases because of eating habits.

  Pi Qianqian of Pingdingshan University is a member of the battle for postgraduate entrance examination. During the summer vacation, she suffered from acute gastroenteritis due to irregular diet, which made her miserable. "My stomach is super painful. I cried so hard that I went to see a doctor outside the school, and my whole body was shaking."

  "Everyone must eat well." Pi Qianqian said that she was faced with intense review during the postgraduate entrance examination, and she had to go to the library to review at five or six in the morning. Breakfast was basically a "fool" in the past, and dinner was often eaten after the review at night, which eventually led to acute gastroenteritis. "Now have a good meal. I dare not get sick again during the postgraduate entrance examination. It is too time-consuming."

The picture shows the proportion of college students who have had gastrointestinal diseases due to their eating habits. China Youth Network reporter Li Huaxi cartography

The picture shows the proportion of college students who have had gastrointestinal diseases due to their eating habits. China Youth Network reporter Li Huaxi cartography

  College teachers suggest that we should develop good eating habits and exercise reasonably.

  Ma Shutan, a food science counselor at Anhui Normal University, believes that some college students don’t have good work and rest habits, which leads to their inability to insist on eating breakfast. "Students are still very young and have not realized the importance of eating habits to themselves."

  "The body is the capital of the revolution, which not only requires us to pay attention to exercise, but also pay attention to our own diet and lay a good foundation for ourselves." As a counselor and companion around students, Ma Shushan hopes that students can pay attention to their living habits, reasonably match their meals, and replenish their energy on time and in quantity, so as to have a strong body.

  For the results of this survey, Zhao Qiong, a preventive medicine teacher at Chongqing Medical College, said that these dietary problems are indeed common among college students, and students should reasonably arrange three meals a day according to the six dietary guidelines recommended by China Nutrition Society, that is, "the food is diverse, mainly cereals; Eat balance, healthy weight; Eat more fruits and vegetables, milk and soybeans; Eat fish, poultry, eggs and lean meat in moderation; Less salt and less oil, controlling sugar and alcohol; Put an end to waste, promote new food, and ensure both quantity and quality.

  Zhao Qiong also suggested that there should be more than 12 kinds of foods that are not repeated every day and more than 25 kinds a week; Exercise at least 5 days a week, and do moderate-intensity exercise for more than 30 minutes a day; Do not exercise immediately after meals, so as not to affect the digestion of food. (At the request of the interviewee, the students in this article are all pseudonyms.)

  (China Youth Network reporter Li Huaxi correspondent Jiang Yujun)

In ancient times, the imperial examination cost nothing, and the martial arts examination took three days. The examination questions were large and complicated.

  Imperial Examination, the earliest "college entrance examination" in China, began in the Sui Dynasty. Champion, a term that is still full of charm and vitality and envied by all, is the invention and creation of the only female emperor Wu Zetian in China history.

  What is "Imperial Examination"

  "Imperial Examination" means to select people by subject. The real imperial examination system in China began with Emperor Wen of Sui, Emperor Wen of Sui Dynasty, and followed Yang Guang, Emperor Yang of Sui Dynasty. After the unification of the whole country in Sui Dynasty, Emperor Wendi of Sui Dynasty put the power of selecting officials under the central government, abolished the Nine-Graded System, and began to select officials by examination. Emperor Yangdi loved literature, set up the imperial examination department, and selected scholars by "trying strategy". This was the beginning of the imperial examination text for future generations, and also set up the Ming Classics Department, which marked the official birth of the imperial examination system.

  Judging from the history books, Yang Guang’s promotion of the system of selecting officials in imperial examinations was not a political show. At that time, it was really out of the need to select outstanding talents. In the Tang dynasty, the imperial examination field came out of the "No.1 scholar". The first scholar is the champion, and in today’s words, he is the champion in the examination room. This term, which is still full of charm and vitality and envied by all, is the invention and creation of the only female emperor Wu Zetian in China history. Since then, the "number one scholar" has become synonymous with outstanding students.

  Specifically, the scores of the ancient "college entrance examination" were divided into three grades: one, two and three. Only three people are taken from one armor. The first name "No.1 Scholar", the second name "No.2 Scholar" and the third name "Flower Exploration", called "Three Ding Jia", are all given to "Jinshi Ji"; Second, take several names (according to the needs of officialdom), all of which are given "Jinshi origin"; The top three take a number of names, all of which are given "the same Jinshi origin."

  There are many rules in ancient imperial examinations and they are quite complicated. The complete procedure includes the provincial examination, the general examination and the court examination, that is, the local, central and imperial examinations. As we all know, the examination place is located in each province after having obtained the provincial examination. After having obtained the provincial examination, it is also called Xiang Wei, and passing the provincial examination is called "Zhongju" and becomes a juror. Formally speaking, after having obtained a provincial examination can be regarded as the "unified examination for ordinary colleges and universities in China" in ancient China.

  Ancient imperial examinations were nothing but martial arts.

  Just as it is not easy to be among the best now, it is even more difficult to get the top scholar in ancient times. Therefore, most of the top scholars in ancient times were truly knowledgeable people, and even the emperor liked to marry his daughter to the top scholar Lang.

  After the resumption of the "College Entrance Examination" in the late 1970s, for a long time, all the candidates in Qian Qian took the same examination paper. The ancient imperial examination was the same at the beginning, and the national unified examination was implemented. In most years, it was a list of officials. However, since ancient times, there have been talented people in the south of the Yangtze River, and the northern scholar has been in the imperial examination field. On the whole, it is obvious that he can’t pass the examination of Jiangsu and Zhejiang scholars. Later, for the sake of justice, balance and care, in the final round of "Finals" in palace examination, some dynasties, such as the Ming Dynasty, divided the examination questions and examination times between the south and the north, and there were even three volumes between the south, the north and the middle.

  The current college entrance examination is divided into arts and sciences, and the ancient imperial examination is also divided into subjects, which are different from arts and martial arts. Therefore, there is a difference between the literary champion and the martial arts champion. According to research, the first martial arts champion in ancient China was named Xue Yi; There are too many famous literary champions, such as Wang Wei, a great poet in the Tang Dynasty, Wen Tianxiang, a national hero in the Song Dynasty, and Zhang Jian, an industrialist in the late Qing Dynasty.

  How many books should I recite in the imperial examination?

  According to statistics, candidates have to recite The Analects of Confucius, Mencius, The Book of Songs, The Book of Rites and Zuo Zhuan, with a total of more than 400,000 words, all of which should be carefully read and memorized. In addition, candidates have to read several times as many notes as the original text, as well as other classics, history books and literary books that must be read.

  In ancient times, there were four subjects to be studied in the "College Entrance Examination", namely, eight-part essay, poem, classics and law. The topics of the eight-part essay are mainly taken from the Four Books: The University, The Doctrine of the Mean, The Analects of Confucius and Mencius. Trial post poetry is a kind of poetic style. In the examination, a poem and idiom of the ancients are used as the topic, and a rhyme is defined, and a poem is written with the content of praising the state affairs.

  The examination time is three days.

  In ancient times, the examination time was also very fixed, but it was not limited to one examination. In some dynasties, there were spring examinations and summer examinations. The "palace examination" who finally decides the top scholar is usually arranged in the spring of March, which is the so-called "March Tingkao".

  In ancient times, the examination time was generally divided into three days, but instead of connecting the examinations as it is now, two days were left in the middle. During the Ming and Qing Dynasties, after having obtained the provincial examinations, they were held in August of the lunar calendar, and in February of the lunar calendar, and in March of palace examination. The time for the township and the meeting is set at the ninth, twelfth and fifteenth days of the month.

  Jiangnan after having obtained the provincial examinations is mostly held in autumn, so it is also called "Autumn Wei". Three games each, three days and nights each. Because there are two changes in the middle, it is actually nine days and seven nights.

  The first test was an eight-part essay, which was selected from the four books and five classics. The second test is the practical writing of officialdom, which is divided into two types: official documents and judicial judgments based on cases provided. The third exam question involves specific national economy and people’s livelihood issues, and requires candidates to give countermeasures and methods. At that time, the scientific examination was a candidate and a major event of the imperial court. In order to ensure the smooth progress of the examination, the building would be locked after the examination, and no matter what happened, even if there was a fire, the candidates could not be unlocked.

  At that time, all the buildings were lined south, with nearly 100 long ones and 50 or 60 short ones. At the entrance of the lane, there is a font size, equipped with a signal lamp and a water tank, which can be used by candidates to travel at night and drink water during the day. During the examination, the candidates will provide their own meals. Because it takes a long time to have a rural examination and the weather is sultry, the food will soon deteriorate, so candidates usually only bring dry food to satisfy their hunger.

  The examination questions are large and complicated.

  For the types of test papers, the dynasties are similar. The subjects tested in each dynasty have not changed much in general, but the number of questions is very large. According to the different subjects selected, it is possible to obtain fame only by completing the corresponding examination papers. On the surface, it is simpler than the current college entrance examination papers, and it seems that it is only a composition, but in fact it is more complicated, and it is a lifelong test. Because of the large number of examination questions and the long time, there are often incidents of "killing" candidates: some students can’t stand the torture, throw themselves into the water and leave.

  At that time, the relevant measures to prevent cheating were very strict, the examination room was closed, and a row of numbered houses separated the candidates.

  The brick walls on the left and right sides of the building are between one and two feet from the ground, and two brick supports are built, so that upper and lower boards can be placed on them. In the daytime exam, the upper board replaces the console table, and the lower board is a stool for candidates to sit and answer questions. At night, the upper board is taken out and merged into the lower floor to be used as a bed for sleeping. However, because the length of the building is only four feet, which is equivalent to 1.33 meters, people can’t even straighten their legs when they sleep. Moreover, there is no door in the building, so candidates need to bring their own tarpaulin as a door curtain to prevent wind and rain.

  Because the weather is very hot in autumn, the candidates eat and live in a small building. Therefore, there are often candidates who die accidentally because of heatstroke and food poisoning, while others are killed by poisonous snakes hiding in the eaves of the building.

  Ancient candidates were very hard.

  Parents and educators have been calling for reducing students’ burden for years. In fact, this wish has been shouted for more than 1000 years. The college entrance examination in ancient times was also a major event for families. Like parents accompanying and sending exams now, parents in ancient times were also very dedicated, which was the only channel for children to lead their careers.

  In ancient times, students couldn’t just read books. They had to recite classics like the Four Books and the Five Classics, memorize them by heart, and even get a clear picture of a sentence on a page and a line. The ancient college entrance examination was even more beautiful in calligraphy, but it was three or nine in winter and three days in summer. The results of studying for many years were much more painful than those of modern students.

  As far as the provisions of the Ming and Qing Dynasties are concerned, not all students can take the township entrance examination. The first choice is to pass the quiz, which is commonly known as the boy test, and it is possible to become a scholar. Scholars have to pass the annual examination and the departmental examination before they are eligible to take the provincial examination. The departmental examination is held before the provincial examination, which can be regarded as a pre-examination for the provincial examination. Scholars who passed the examination were allowed to take part in the ancient "college entrance examination" after having obtained the provincial examination. If you fail the exam, it is called "falling into the sea", and those who fall into the sea still have a chance to make up the exam, which is called "failing to pass the exam"

  After passing the provincial examination and becoming a juren, you can take part in the meeting presided over by the Ministry of Rites. Because the examination room for the exam is located in Beijing, there is a saying that "going to Beijing to catch the exam". Candidates who pass the final exam, called "Gong Shi", are qualified to take the final and highest-level exam.

  There was a system of sealing volumes in ancient times.

  At present, the college entrance examination stipulates that there is a strict system of sealing papers, and the examination papers will be sealed as soon as each exam is over, so as to prevent artificial disadvantages in marking the exam papers. In fact, this system of sealing papers has existed for a long time in the ancient "College Entrance Examination".

  According to historical records, the ancient imperial examination system in China began in the Song Dynasty. According to the Song History Election, during the Chunhua period in Song Taizong, the method of "pasting the name to test the school" was adopted at the suggestion of Chen Jing, the examiner, and the candidates’ names and places of origin were pasted on the test paper, and it was decided to open the test paper before sealing it.

  The specific method is: the test paper should be pasted with the name, which is called "sealed". The method is that after the examination paper is handed in, the sealing officer will fold the paper, seal the candidate’s name and number it in red; Then, the transcriber will copy the test paper with Zhu Pen, which is called "Zhu Juan" and send it to the examiner for review. When the list is released, the "black roll" will be unpacked according to the red number of the "Zhu roll" selected, and finally the list will be written by roll call.

  The examiner is the deputy examiner. If he likes any recommendation paper, he will mark it with the word "take"-the so-called "admission" in the modern college entrance examination, which is probably how it came about. The papers marked with "take" will be sent to the examiner, who will finally decide the fate of the candidates. If the examiner also likes it, he will approve the word "Zhong" on the test paper-the origin of "Exam Zhong" should come from this.

  Just like today, there are strict rules on the marking time in the past dynasties, which require that the marking be completed within a certain period of time. Take the Qing Dynasty as an example, the time limit for marking papers is 10 days. These 10 days also include the time before sealing, copying and reading. In the meantime, it will take a lot of time to eat and invite, so the real marking time is quite tight, but only three or four days. Therefore, at that time, examiners generally had to review twenty papers a day, with thirty or forty more. Ordinary marking staff have more papers to read, so most of them are overloaded. It can be seen that in ancient times when there was no modern computer-aided marking, the marking staff simply had no time to read every test paper carefully.

  In order to speed up marking and finish the work stipulated by the imperial court on time, marking personnel also try their best. One of the most important means is to look at the "first impression", that is, to focus on the candidates’ first exam papers, which is what the ancients called "stop reading the forecourt and stop reading the meaning of the book".

  Under normal circumstances, if candidates do well in the first exam, they get a "high score" when marking papers-good comments, and basically they will be on the list. But if you fail in the first exam, even if you play well in the last two games, you may lose your reputation in Sun Shan. Therefore, candidates at that time paid special attention to answering the first exam.

  Looking back, the "paste-name examination" method in the Song Dynasty was obviously regarded as the "ancestor" of the college entrance examination system.

  Allow failed students to search the papers

  It can be said that there are more subjective factors in marking papers in ancient times than in modern times, which have a great influence on candidates’ grades. Many failed students were missed by irresponsible marking personnel. Therefore, some examiners with a strong sense of responsibility will randomly check the "failed papers" that have not been tested, and the examiner also has the right to read the recommendation papers that have not been "taken" by the deputy examiner for review.

  In addition, there is a more humane provision-allowing failed students to check the papers, which is also a good way to supervise the marking staff. If the excellent papers are graded badly, once the candidates petition, they will be in big trouble, and the responsible person will be punished by the court.

  During marking, the ink roll has been stored in the outer curtain and kept by the outer palm. After all the marking work is finished, the original volume will be transferred out against the admitted Zhu volume, the personal information of the candidates will be found out, and the name of the list will be filled in. Next, it’s time to release the admission list. After the release of the list, the admitted Zhu Juan and Mo Juan will be re-assembled and sent to the Ministry of Ritual (equivalent to the current Ministry of Education) for review.

  At this time, the failed candidates can check the papers. Generally, within 10 days after the announcement of the test results, the candidates who failed the exam can check their own papers. There will be the examiner’s marking comments on the papers, and at first glance, you will understand why you have not been admitted, which is also a dead end.

(Source: Yanzhao Evening News)

How to choose pure water, mineral water and natural water?

Beijing, March 25 (Xinhua) According to the Beijing Center for Disease Control and Prevention, with the improvement of people’s living standards and the enhancement of health awareness, more and more consumers are used to buying bottled water or bottled water in their daily lives. Mineral water, natural water, distilled water … There are many kinds of drinking water in the market, which makes people dazzle. What’s the difference between these different names of water?

Bottled water and bottled water in the market belong to packaged drinking water. At present, the common packaged drinking water can be roughly divided into three categories: pure water, natural water or natural spring water and mineral water.

Pure water:

Purified drinking water is made by distillation, electrodialysis, ion exchange, reverse osmosis or other appropriate water purification processes. Distilled water on the market also belongs to pure water.

In the process of treatment, purified water removes harmful components such as bacteria, viruses, heavy metal elements and organic substances, and has low hardness and good taste, and can be directly drunk, without forming scale when boiling water. However, in the process of treatment, minerals beneficial to human beings such as potassium, calcium and zinc are also removed.

Natural water/natural spring water:

Drinking natural water and drinking natural spring water are all made from natural sources that have not passed through the public water supply system. The difference is that the water source of natural water can come from wells, mountain springs, reservoirs, lakes or alpine icebergs, while natural spring water can only come from underground springs.

These two kinds of water only need minimal treatment (such as filtration, ozone or equivalent treatment), that is, impurities and harmful substances in the water are removed, and the original minerals and trace elements beneficial to human beings are retained. The composition and proportion of mineral elements in natural water/natural spring water from different water sources are different, and there are also some differences in taste and water quality.

Mineral water:

The mineral water we talk about every day mainly refers to drinking natural mineral water. Drinking natural mineral water is water that naturally gushes from deep underground or is collected by drilling, contains a certain amount of minerals, trace elements or other components, and is unpolluted in a certain area and preventive measures are taken to avoid pollution; Under normal circumstances, its chemical composition, flow rate, water temperature and other dynamic indicators are relatively stable within the natural periodic fluctuation range.

Mineral water belongs to natural water in essence, but natural water is not necessarily mineral water. Mineral water must be deep groundwater, and its components such as minerals or carbon dioxide must meet one or more of the boundary indicators in national standards. Generally speaking, mineral water has stable water quality, little microbial content, and contains a certain amount of minerals and trace elements needed by human body, such as zinc, selenium and strontium.

In other words, the key to distinguish various packaged drinking water depends on its water source and implementation standards.

From the point of view of water source, pure water comes from public water supply or non-public water supply, while natural water, natural spring water and mineral water come from non-public water supply.

From the standard point of view, pure water, natural water and natural spring water implement the national standard for food safety-packaged drinking water (GB 19298-2014), while natural mineral water implements the national standard for food safety-drinking natural mineral water (GB 8537-2018).

Different packaged drinking water has different water quality and taste because of its different components.

What kind of water should we choose for our daily drinking?

From a health point of view, natural trace elements and minerals in water are valuable nutrition and health resources, so the more "pure" water is, the better. We should try our best to keep natural elements beneficial to human body and remove harmful components.

Scientific research shows that moderate amounts of calcium and magnesium in water have protective effects on cardiovascular health. Although the magnesium provided by water only accounts for 2%-4% of the human body’s needs, it can still play an important role for those who are mildly deficient in magnesium, such as those who take diuretics because of hypertension and heart disease.

In addition, compared with magnesium in food, magnesium in dissolved ionic state in water is more easily absorbed by human body. The World Health Organization (WHO) points out that drinking water without minerals for a long time can directly or indirectly lead to low or even zero absorption of beneficial minerals.

Therefore, pure water should not be used as a single daily drinking water for a long time, and it can be drunk occasionally or alternately with other types of drinking water.

Although purified water is not suitable for long-term drinking, in some cases, such as making tea, it has a unique advantage because it does not contain "impurities". As the saying goes, "water is the mother of tea", and good tea needs proper water brewing to complement each other. Scientific research shows that mineral content, pH and electrical conductivity in water are the main factors affecting the quality of tea. Higher pH will make the color of tea darker; Minerals easily react with some taste substances in tea, thus affecting the color and taste of tea. Pure water has a low pH and the least mineral content. When used to make tea, the soup is bright in color and pure in fragrance, which can best reflect the original taste of various teas.

So the higher the mineral content, the more beneficial it is to human health? Trace elements and minerals in water may improve some chronic diseases, such as digestive tract diseases. However, water with high mineral content is not suitable for everyone. In some cases, it is "too much" and must be selected according to its own situation.

★ If some studies believe that the immature kidneys of infants and young children, such as high mineral content in water, will increase the burden on the kidneys;

★ Children and people with weak renal function (such as renal dialysis patients, the elderly, etc.) should avoid drinking water with high strontium content for a long time, because low calcium intake may cause the risk of bone health for such people.

In fact, besides packaged drinking water, the most healthy and economical daily drinking water for ordinary people is boiled tap water, that is, boiled water. Tap water is the most common drinking water in China at present. It is taken from natural water sources on the surface or underground, purified and disinfected by a series of treatment processes, and then transported to thousands of households.