The scientific rumor list is coming in May: Old people donate blood to lower blood fat. China is the only big country where salt is forcibly iodized. Fatty chubby grows thinner
when it grows up. Is it rumored that the wind and rain will accelerate the spread of the new crown virus? fake

  Windy and rain will accelerate the spread of the new crown virus, the heat in summer can end the virus, blood donation can reduce blood fat in the elderly, China is the only big country with salt to be forced to iodine...The most heated topics that you have heard recently have even been discussed. It is a "pseudo-proposition". The "Science" rumors list was released in May, which involved five popular health rumors to see if you were "flickered". The "Monthly "Science" Gossip List" is under the guidance of the Beijing Science and Technology Association, the Beijing Internet Information Office, and the Capital Internet Association, and is jointly released by the Beijing Science and Technology Journalists' Editing Association and the Beijing regional website joint rumor platform.

  Rumor: The wind will blow the virus everywhere, rain will make the virus multiply faster, and will accelerate the spread of the new coronavirus.

  The truth: nonsense. First of all, the wind will not only accelerate the spread of the new coronavirus, but also slow down the spread.

  Gale does blow the virus everywhere, but it does not blow the virus to the same place, only the high concentration of the virus. A few days ago, academician Zhong Nanshan said in an interview with the media that the virus should be attached to something to spread. The most prominent thing is through the droplets. The virus is quickly diluted in the wind, and the virus cannot naturally reach a certain concentration in air propagation.

  In addition, rain will not increase the risk of spreading the new coronavirus. In a humid environment, bacteria may multiply faster, but viruses and bacteria are different, they can only parasitize and reproduce in the host body, so moisture will not increase the number of viruses. In addition, the virus floats in the air in the form of tiny droplets. After rain, these tiny droplets will attach to the rainwater and fall to the ground to be washed away, so that they cannot enter everyone's mouth and nose and cause infection. In other words, raining will not only accelerate the spread of new coronavirus, but also reduce the number of viruses floating in the air and reduce the risk of infection.

  Rumor: The new coronavirus is afraid of heat. As the temperature rises in summer, the spread of the new coronavirus will end.

  Truth: As the weather starts to get hot, wearing masks becomes more uncomfortable, but this is not the reason to not wear masks and relax your vigilance. Hot weather can indeed reduce the spread of new coronary pneumonia, but the effect is limited.

  Christopher Murray, director of the Institute of Health Indicators Evaluation at the University of Washington, said they found through statistical studies that for every 1°C increase in temperature, the rate of new coronavirus transmission can be reduced by approximately 2%. But high temperatures alone cannot successfully contain the virus. For example, Australia, the southern hemisphere in summer, and Singapore and Malaysia, which are located in the tropics and have high temperatures and rain all the year round, are still seriously affected.

  Public precautions such as isolation, maintaining social distance, and wearing masks are more effective than pure temperature. Don't be lucky because the weather is hot, don't wear a mask at will.

  Rumor: Old people often donate blood to lower blood fat.

  Truth: According to the guidance of relevant professional institutions, proper blood donation will not be harmful to health. But don't use blood donation as a means to lower blood fat.

  The total blood volume of a healthy person is about 8% of body weight, about 4000-5000 ml. Normally 80% of the blood circulates in the heart and blood vessels to maintain normal physiological functions; 20% of the blood is stored in the liver, spleen and other organs. When blood loss or vigorous exercise, these blood will enter the blood circulation system. A person donates 200-400 ml of blood at a time, accounting for only about 5% of the total blood volume. The blood stored after blood donation will be replenished immediately, so blood donation will not reduce the circulating blood volume, nor will it affect people's health function.

  In theory, blood donation draws a portion of blood, and blood lipids may drop slightly in the short term. But in fact, our body has the ability of self-regulation. When the blood lipid content decreases, the body will quickly produce blood lipids, so even if blood lipids slightly drop in the short term after blood donation, it will soon adjust back to the original level.

  Therefore, it is not worth advocating blood donation as a means of lowering blood lipids. In fact, the simplest and most effective way to lower blood fat is to take a medicine to lower blood fat as directed by your doctor, in addition to a healthy diet and reasonable exercise.

  In addition, my country's "Blood Donation Law" stipulates that people aged 18-55 years old, men weighing more than 50 kg, women weighing more than 45 kg, healthy citizens can participate in blood donation. For reasons such as diet or nutrient absorption, blood donation is not recommended for the elderly.

  Rumor: China is the only major country that has iodized salt forcibly, while iodized salt is rarely used abroad.

  Truth: Iodine deficiency is a global public health problem, and iodine fortification through food is the fundamental way to solve this problem. Since 1993, the United Nations and the World Health Organization have implemented global iodization of table salt, that is, edible salt for human consumption, salt for animal feed, and salt for the food industry. By 2008, more than 120 countries and regions in the world have implemented salt iodine fortification policies, of which 34 countries and regions have implemented mandatory salt iodization, including China and India, which have the largest populations. From 1993 to 2013, the number of countries and regions deficient in iodine decreased from 110 to 31.

  "Less iodized salt in foreign countries" and "Do not force iodine in foreign countries" are just appearances. This is because different countries have different diet structures, different salt habits, and different iodine fortification strategies. For example: Thailand and Cambodia, because the most commonly used salty seasoning is not salt but fish sauce, so I choose to add iodine to the fish sauce, so there is no iodized salt; about 75% of the salt intake of consumers in Western countries comes from processed food Therefore, iodine fortification in processed foods, especially bread, is their popular practice.

  The iodine fortification policies vary greatly from country to country, but the ultimate goal is the same: to achieve adequate iodine nutrition for all. The dietary habits of the Chinese determine that salt iodization at retail is the most effective and economical iodine fortification strategy with the largest coverage.

  Rumor: It doesn't matter if the child gets fat when he was a child, he will naturally lose weight when he grows up.

  Truth: Over the past few decades, the global prevalence of children overweight and obesity has been increasing year by year. In childhood, obesity is not only closely related to diseases such as asthma, adenoid hypertrophy, childhood diabetes, fatty liver in children, and central precocious puberty, but it may also affect the health of adults.

  Research from the Chinese Center for Disease Control shows that during 13 years of follow-up, 80% of obese children will develop into adult obesity. Therefore, preventing the increase in the prevalence of childhood obesity is an important issue faced by public health and clinicians in my country.

  In fact, poor eating habits are closely related to childhood obesity, such as skipping breakfast, snacking and frequent intake of sugary drinks and eating too fast. School-age children should pay attention to the relatively fixed time for three meals, balanced nutrition, less oil and salt condiments, etc.; drink plenty of water, do not drink sugary drinks, drink more boiled water; do not overeating, because overeating may be Increase the burden on children's digestive system, causing heat accumulation, leading to children's overweight and obesity.

  How to judge whether the child is overweight and obese? A simple assessment can be made initially through the child's BMI. BMI (Body Mass Index), referred to as body mass index. BMI calculation formula: BMI = weight (Kg) / square of height (m2), for example, a 52Kg person whose height is 1.55m, then the BMI is: 52(Kg)/1.55 ​​square (m2) = 21.6. At the same time, the assessment was conducted with reference to the “Growth Curve of Body Mass Index for Children and Adolescents Aged 0-18 in China”. If the child belongs to the category of overweight and obesity, it is necessary to go to the hospital as soon as possible to assess whether there are other obesity comorbidities, and formulate effective diet and exercise strategies to prevent the further development of obesity.

  Text / reporter Li Jie