May 2024 "Science" Rumor List: Will QR codes be used up soon? Can "Physical Exam Magic Tool" improve scores?

The May 2024 "Science" Rumor List is revealed! Will the QR codes run out soon? Drinking a bottle of "Physical Exam Magic" before the exam can improve your grades? Is melatonin a "magic drug" for insomnia? Come and find out the truth. The monthly "Science" Rumor List is guided by the Beijing Association for Science and Technology, the Beijing Municipal Cyberspace Administration, and the Capital Internet Association, and is jointly released by the Beijing Science and Technology Journalists and Editors Association and the Beijing Regional Website Joint Rumor Refutation Platform. It is supported by the Science and Technology Journalists and Editors Professional Committee of the China Science Writers Association, the China Evening News Science Editors and Journalists Association, the Shanghai Science and Technology Communication Association, and the Institute of Science and Technology Information of the Beijing Academy of Science and Technology.

1. Can juice and vitamin tablets replace fruits?

gossip:

Eating more fruits can supplement vitamins, but some people don’t like to eat fruits, so “vitamin tablets” and fruit juice can be used as substitutes.

the truth:

Each kind of fruit and vegetable contains hundreds of ingredients, which cooperate and protect each other. Vitamin supplements and fruit juices with relatively single ingredients are difficult to achieve the health benefits of natural foods. In addition, for healthy people, blindly or excessively supplementing a few nutrients through health products may cause or aggravate metabolic disorders of other nutrients and increase the burden on the body.

During the processing of fruit juice, certain dietary fiber, vitamins and other nutrients will be lost. Moreover, we need to spend time chewing when eating fruit, while juice with high sugar content is often drunk in one gulp. Drinking it frequently will make teeth lack exercise and increase the risk of tooth decay and obesity.

Fruits and vegetables are rich in nutrients. The dietary fiber they contain can promote intestinal health, prevent constipation, and delay blood sugar absorption. The inorganic salts such as calcium, phosphorus, iron, potassium, and sodium can not only maintain cell morphology and function, promote the life activities of organisms, but also maintain cell osmotic pressure and acid-base balance. The organic acids they contain can stimulate the human digestive glands, increase appetite, and help digestion. Various enzymes, bactericidal substances, and physiologically active ingredients with special functions, as well as terpenoids, polyphenols, plant sterols and other plant chemicals play an important role in maintaining human health. The Dietary Guidelines for Chinese Residents (2022) states that each person should consume no less than 300 grams of vegetables and 200-350 grams of fresh fruit per day. Therefore, it is recommended that daily meals should be diverse and nutritionally balanced.

2. Will QR codes run out soon?

gossip:

According to incomplete statistics, the global usage of QR codes is as high as more than 10 billion per day. Therefore, QR codes will soon be used up.

the truth:

Theoretically, the variations of the arrangement and combination of black and white squares in a fixed area are limited, and when the stored data exceeds the capacity limit, the QR code will be used up. However, in practical applications, the capacity of the QR code is usually very large, far exceeding the amount of data we usually need to store.

Take the WeChat payment code that we usually use as an example: there are 25×25, or 625 small squares in this QR code matrix. Excluding some squares with functions such as positioning and error correction, there are 478 squares left. Each square is black and white, which means that 2478 different QR codes can be formed.

Assuming that 10 billion payment QR codes are used every day and 365 billion are used every year, it will take 2.14×10131 years to use up all the payment QR codes. The universe has only been around for 13.7 billion years, or 1.37×1010 years, which is much less than the time it takes to use up all the payment QR codes. Therefore, we don’t need to worry about running out of QR codes anytime soon.

3. Can eating honey cause diabetes?

gossip:

Eating honey can cause diabetes.

the truth:

This statement is not rigorous. The main components of honey are glucose and fructose. Glucose is an essential substance for the human body. Normal people who consume a moderate amount of honey every day will not cause diabetes. If you are already in the pre-diabetes stage or are obese, you should reduce your honey intake. It is recommended that adults do not consume more than 50-60 grams of honey per day, and 20-30 grams is appropriate. If you already have a genetic predisposition to diabetes, high blood sugar, abnormal pancreatic function, etc., consuming excessive amounts of honey every day may induce diabetes.

4. Can “hanging the neck for fitness” cure cervical spondylosis?

gossip:

In recent years, the "neck hanging fitness" for the elderly has become popular on the Internet. As long as the head is hung on a tree and the body swings along the rope, regular practice can cure cervical spondylosis.

the truth:

Although "hanging the neck for fitness" refers to the clinical traction principle, it is not advisable to do it blindly. Some middle-aged and elderly people have some cervical spine diseases, and the human body has a certain physiological curvature. Blindly "hanging the neck" not only cannot exercise, but also has great safety hazards, which may damage the nerves and spinal cord, and in severe cases, it will lead to high paraplegia or even death.

In addition to "hanging neck" fitness, there are many other "fitness" methods, such as headfirst to the ground, hitting the tree, "spinning" on parallel bars, etc. Some of these "fitness" violate the human physiological structure and are not suitable for everyone.

Therefore, it is recommended that you make a reasonable assessment of your body before exercising. Athletic ability varies from person to person, so you must not blindly imitate others and cause unnecessary damage to your body.

5. Before the physical education test, drinking a bottle of "physical test magic" can improve your performance?

gossip:

The functional drink, known as the "magic weapon for physical examinations", can help children taking physical examinations improve their test scores.

the truth:

In the ingredient list of "Physical Test Artifact", excluding water and carbohydrates, the highest ingredients are taurine and caffeine. For example, a 60 ml "little green bottle" contains 540 mg of taurine, and a 60 ml "little black bottle" contains 180 mg of caffeine. According to the "National Food Safety Standard General Rules for Sports Nutrition Food", the maximum daily intake of taurine in various sports products is 600 mg, and the daily use of caffeine should be between 20 mg and 100 mg. Obviously, this type of product may cause users to exceed the intake limit of certain ingredients, affecting their health.

Functional drinks are generally aimed at adults. Improper consumption by adolescents in the growth and development stage may cause disorders in the body system. Taurine and caffeine are both neurostimulants. Adolescents have low tolerance to them and are more sensitive to them after ingestion. If they are consumed improperly, not only will sleep be easily affected, but in severe cases, poisoning may also occur. In addition, functional drinks are high in sugar, which also increases the risk of obesity and tooth decay among students to a certain extent. Under normal conditions, the human body is in a state of balance. Deliberately supplementing a certain ingredient will disrupt the balance and cause harm to the body.

6. Health supplements can treat many diseases without any side effects. Are they better than taking medicine?

gossip:

Health products are advertised as being able to cure all diseases and have no side effects. Taking health products is safer and more effective than taking medicine.

the truth:

By definition, health care products are just a kind of food with health care functions, not for the purpose of curing diseases. Therefore, health care products are first of all a kind of "food". Medicines are products used to control, prevent and treat diseases, with clear indications, applicable populations, usage and dosage. The difference between the two is self-evident. As a food, health care products, like rice, noodles and steamed buns, do not have the function of curing, preventing and regulating diseases, while medicines are the "correct answer" to diseases.

Blindly trusting health care products may lead to loss of money and delayed treatment. Some substandard health care products may even lead to excessive intake of effective ingredients, threatening health. It is not that we cannot use health care products, but we should not rely on them to cure diseases, nor can we rely solely on taking health care products to the point of ignoring healthy living habits.

7. Eggs are high-cholesterol foods, so it is best not to eat eggs if your cholesterol is high?

gossip:

Eggs, especially the yolks, are high in cholesterol. People with high blood lipids should not eat them. Healthy people should also pick out the yolks and not eat them to avoid increasing cholesterol.

the truth:

This statement is not rigorous. Eggs contain high-quality protein, trace elements, lecithin, etc., which can promote brain development and improve immunity. They are very good food. As long as you choose the right type of eggs, use proper cooking methods, and match the right ingredients, even patients with high blood lipids can eat eggs appropriately.

First of all, compared with meat, the cholesterol content in egg yolk is not ridiculously high, and there are eggs that are fed with special feeds with significantly lower cholesterol content. Secondly, there is no need to worry if you don’t consume too many eggs per week. For example, eating 4-5 eggs is a good choice. When cooking eggs daily, you can combine them with vegetables, beans, fungi, and whole grains as staple foods, which is more conducive to nutritional balance and disease prevention.

8. Melatonin is a “magic drug” for treating insomnia. Is it safe and has no side effects?

gossip:

Melatonin is a safe and effective treatment for insomnia.

the truth:

This statement is not rigorous. There are too many types of insomnia, and melatonin is only effective for insomnia caused by melatonin deficiency or jet lag. It has little effect on insomnia caused by other reasons. Taking melatonin cannot play a therapeutic role.

In the fast-paced modern life, lack of sleep and poor sleep quality have gradually become a common problem that troubles the public. Among the many sleep aids, melatonin is known as a "healthy hypnosis" because it is a substance naturally produced by the human body, and its related products are enthusiastically sought after by consumers.

Melatonin is a hormone in the human body that regulates sleep. The synthesis and release of melatonin in the brain is related to the time of day, increasing when it is dark and decreasing when it is light. The secretion of melatonin also decreases with age. However, melatonin is not a panacea. It is only effective for insomnia in the following two situations:

The first: jet lag. There is evidence that melatonin can reduce jet lag, especially when travelers cross 2 to 5 time zones eastward. Oral melatonin can improve some symptoms of jet lag, such as alertness, and reduce daytime sleepiness and fatigue.

The second type: insufficient melatonin secretion. Studies have shown that melatonin can shorten the time it takes to fall asleep. Generally speaking, melatonin secretion begins to decline after the age of 35, and additional melatonin supplementation may be more effective for elderly people who lack melatonin. Therefore, melatonin is not suitable for everyone.

In addition, melatonin, as a "hormone", has "side effects" if used improperly, such as headaches, drowsiness, short-term depression, etc. Therefore, when purchasing melatonin products, be sure to choose qualified products produced by regular manufacturers and take them according to the doctor's advice.

9. Hypertensive patients should avoid exercise as they are more likely to die suddenly?

gossip:

People with high blood pressure should not exercise as they are prone to sudden death.

the truth:

This statement is too absolute. Hypertension is not a contraindication to exercise. Reasonable exercise can lower blood pressure, but reckless exercise may increase the risk of sudden death.

Studies have shown that reasonable and regular exercise can relieve sympathetic nerve tension, increase vasodilators, improve endothelial relaxation function, promote glucose and lipid metabolism, and prevent and control hypertension.

It should be noted that regular exercise should be performed under the premise of stable blood pressure control. Patients with uncontrolled severe hypertension, hypertensive crisis or rapid hypertension, unstable angina, heart failure, severe arrhythmia, retinopathy and other symptoms are advised not to exercise blindly. If you want to exercise, it is best to wait until the condition is stable, go to the cardiovascular department for consultation, and follow the doctor's advice before exercising.

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