List of "Science" Rumors in June 2024: Can you take antipyretics to reduce the temperature when you have a heat stroke? Are foods safer with a shorter shelf life?

The list of "scientific" rumors for June 2024 is revealed! Can you take antipyretics to cool down after getting a heat stroke? "Black technology" sun-proof clothing not only protects against the sun, but also moisturizes, cools down and repels mosquitoes? Can you save more electricity by turning the air conditioner on and off? Come and find out the truth.

Can I take antipyretics to reduce the temperature if I have heatstroke?

“Black technology” sun protection clothing, not only protects against the sun but also moisturizes, cools down and repels mosquitoes?

Would it save more electricity if we turn the air conditioner on and off for a while?

Are people who are in better and stronger physical condition more likely to suffer from heatstroke?

Will donating blood make people weak?

Can you lose weight faster by eating only vegetables?

Will eating too much soy products cause gout and cancer?

Is food safer the shorter its shelf life?

The whiter the teeth, the better?

Does elevated tumor markers mean cancer?

1. Can I take antipyretics to reduce the temperature if I have heatstroke?

gossip:

Heatstroke, like fever caused by bacterial or viral infection, will heal just by taking antipyretics to reduce the temperature.

(Photo source: Visual China)

the truth:

The body's internal temperature is regulated by the hypothalamus in the brain. The hypothalamus checks our current body temperature and compares it to the normal body temperature of about 37°C. When the body temperature is low, the hypothalamus promotes the generation and retention of heat; conversely, when the body temperature is high, it cools down by dissipating heat or sweating. The fever caused by heat stroke is because there is a problem with the body's heat dissipation center, which cannot dissipate heat through sweating. Taking antipyretics cannot restore the heat dissipation center to normal, but will have the opposite effect, making the symptoms worse and causing heat stroke. Therefore, physical cooling should be the first choice after heat stroke, such as moving the patient to a cool place or an air-conditioned room, rather than taking antipyretics.

2. “Black technology” sun protection clothing, which not only protects against the sun but also moisturizes, cools down and repels mosquitoes?

gossip:

Recently, a variety of "black technology" sun-protection clothing have appeared on the market. For example, the "facial mask sun-protection clothing" is advertised to have hyaluronic acid added to the product, which can achieve a moisturizing effect when in contact with the skin; the "xylitol sun-protection clothing" is said to be able to quickly reduce the body temperature by 5°C after wearing; there is also the "mosquito repellent sun-protection clothing" with added mugwort ingredients, which claims to have multiple functions such as mosquito repellent and antibacterial.

(Photo source: Visual China)

the truth:

Recently, there have been some "black technology" products on the market, such as "hyaluronic acid mask sun protection clothing", "xylitol cooling sun protection clothing", "wormwood mosquito repellent sun protection clothing", etc. Although the ideas are good, they are actually more hype than reality.

The proportion of hyaluronic acid added in hyaluronic acid sun-protection clothing is extremely low, which is far from the concentration of hyaluronic acid used in the medical beauty industry; xylitol sun-protection clothing only feels cool in the early stage of wearing, and after a long time it is no different from ordinary sun-protection clothing; the mosquito repellent sun-protection clothing has an average mosquito repellent effect, and ordinary clothes can also play a role in blocking mosquito bites to a certain extent.

The national standard stipulates that only when the UPF (ultraviolet protection factor) of a product is greater than 40 and the UVA (long-wave ultraviolet) transmittance is less than 5%, can it be called an "anti-ultraviolet product". Generally speaking, the higher the UPF value, the better the protection against ultraviolet rays. Therefore, before purchasing, consumers can verify the protection effect of sun-proof clothing.

In addition to sun protection, consumers should also pay attention to the material of sun protection clothing. From the perspective of materials, products made of polyester and nylon have better sun protection effects than cotton and silk; from the perspective of color, bright or dark colors have better sun protection effects than light colors; from the perspective of performance, those with good washing resistance are easier to wear for a long time, and those with high air permeability and moisture permeability are more comfortable.

3. Will it save more electricity if we turn the air conditioner on and off for a while?

gossip:

Turn on the air conditioner first, then turn it off when the room is cool, and then turn it on again when the room is hot. Repeat this cycle. This can greatly shorten the air conditioner's cooling working time and save electricity.

(Photo source: Visual China)

the truth:

Frequent switching of the air conditioner actually consumes more electricity. This is because although the air conditioner does not consume energy when it is not working, the energy consumption during the startup phase is very high. If the number of restarts is large, the total energy consumption will exceed the energy consumption of the air conditioner being turned on all the time. Of course, when the time interval between shutting down the air conditioner is long enough, its overall power consumption will definitely be less. However, if the shutdown interval is too long, the human body will feel uncomfortable. If you want the human body to feel comfortable, you need to shorten the time interval between shutting down the air conditioner. Under this premise, the power consumption of turning the air conditioner on and off will generally be greater.

Narrowing the gap between indoor and outdoor temperatures and minimizing heat exchange between indoor and outdoor areas is the most effective way to save electricity.

When cooling in summer, the indoor temperature should not be too far from the outdoor temperature. 26℃ is a reasonable temperature, which can minimize the temperature difference with the outdoor temperature while ensuring human comfort. The same is true in winter. One of the key reasons why the dehumidification function saves electricity is the small temperature difference. In addition to the heat exchange between the air conditioner and the outside air, try to prevent other forms of heat exchange. Blackout curtains and door curtains can effectively prevent some heat exchange.

In addition, there are several ways to save power:

1. Turn off the power completely when the air conditioner is not in use, which can also save electricity. Because any electrical appliance, as long as it is powered on, is in standby mode and is constantly consuming electricity.

2. After the air conditioner enters sleep mode, it will automatically increase the preset temperature, which will also reduce the temperature difference between indoor and outdoor and reduce energy consumption.

3. Inverter air conditioners are more energy-efficient than traditional fixed-frequency air conditioners. This is because during operation, the inverter air conditioner uses the preset temperature as the judgment standard and adjusts the compressor speed by comparing it with the actual temperature measured by the sensor. When the temperature difference is large, it runs at full load, and when the temperature difference is small, it runs at a low speed, thus avoiding the extra energy consumption caused by shutdown and restart.

4. Are people who are in better and stronger physical condition more likely to suffer from heatstroke?

gossip:

The better the physique of a person, the more likely he is to suffer from heatstroke, because the better the physique of a person, the better his adaptability to the environment. Once he adapts to the hot weather, he tends to turn a blind eye to the danger, which makes him more likely to suffer from heatstroke.

(Photo source: Visual China)

the truth:

It is wrong to say that "the fitter the person, the more likely they are to get heat stroke." A more appropriate description should be "almost everyone is at risk of heat stroke, including fit people." Heat stroke is professionally called "heat stroke," which can be divided into classic heat stroke (non-exertional heat stroke) and exertional heat stroke. The former is more likely to occur in the elderly, the weak, and the sick, while the latter is more likely to occur in the strong and healthy working in high-temperature environments.

Classic heat stroke, also known as non-exertional heat stroke, refers to severe heat stroke symptoms that occur when anyone is exposed to high temperatures. The cause of this type of heat stroke can be simply understood as "lying down" - as long as you are exposed to high temperatures, you will experience severe heat stroke symptoms even when you are resting. Therefore, classic heat stroke is prone to occur in children, pregnant women, the elderly, those with chronic underlying diseases, and those with impaired immune function.

The other is exertional heat stroke, which is different from "lying down". In addition to being exposed to high temperature and high humidity, this type of heat stroke usually requires people to do strenuous exercise or labor. Typical groups are athletes, new recruits who have just started training, construction workers, and delivery boys, who all look strong and fit. Of course, for weak people, they can get it even without labor. In other words, no matter how good or bad your physique is, you are at risk of exertional heat stroke.

Survey data show that the weak and sick people who stay at home for a long time are the main group of people suffering from heatstroke, and the mortality rate after the onset of the disease is much higher. For example, elderly patients are prone to have underlying diseases such as hypertension, diabetes, coronary heart disease, and use multiple medications at the same time. These are risk factors that increase the risk of heatstroke and mortality.

5. Will donating blood make people weak?

gossip:

Donating blood will make people "weak", leading to a decrease in the body's immunity, which is not good for health.

(Photo source: Visual China)

the truth:

It has been confirmed by millions of blood donors from all over the world that donating blood in moderation does not harm health. The human bone marrow has a strong compensatory function. Under the stimulation of blood loss, the hematopoietic function of the bone marrow can increase to 6-8 times the normal level. Generally speaking, the water and inorganic substances lost in a blood donation can return to normal levels within 1-2 hours; the plasma protein synthesized by the liver can be replenished within 1-2 days; platelets need 2-3 days, while red blood cells and hemoglobin can return to the level before blood donation in 7-10 days. Donating blood under appropriate conditions can also make the body's hematopoietic function more active, continuously produce new hematopoietic cells, and promote metabolism.

There is no research to show that donating blood in moderation will lead to a decrease in human immunity. In the process of donating blood, some white blood cells and some immune-related lymphocytes will indeed be lost, but from the perspective of the amount of blood donated, a healthy adult will lose very few white blood cells after donating 200ml to 400ml of blood at a time, accounting for only 1% to 2% of the total white blood cells in the human body, and these white blood cells can usually be replenished from the bone marrow in about 2 hours. In fact, healthy people have a strong blood regeneration function and a strong self-regulation ability. A large number of blood cells in the human body are aging and dying at all times. Donating blood will stimulate the body's hematopoietic function, accelerate the formation of blood cells, and promote blood metabolism to meet the needs of the body. Therefore, donating blood in moderation will not significantly affect our immunity.

6. Will you lose weight faster by eating only vegetables?

gossip:

If you want to lose weight faster and more effectively, just eat vegetables.

(Photo source: Visual China)

the truth:

While eating only vegetables may help reduce calorie intake and thus lose weight in the short term, this approach is not healthy in the long run.

Eating only vegetables for a long time will result in insufficient intake of essential nutrients such as energy, protein, fatty acids, fat-soluble vitamins, vitamin B12, iron, and zinc, which will lead to problems such as reduced basal metabolism, muscle loss, anemia, decreased immune function, and endocrine disorders.

The best strategy for weight loss is to maintain a healthy lifestyle through a balanced diet and proper exercise. It is recommended to include a variety of foods in the diet, such as vegetables, fruits, whole grains, lean meat, poultry, fish and shrimp, eggs, beans and their products and nuts to ensure comprehensive nutritional intake, small portions and variety, control food intake and calories, and do not recommend eating sweets and drinking sweet drinks, which will help promote long-term health and weight management.

7. Will eating too much soy products cause gout and cancer?

gossip:

If you eat too much soy products, it will not only cause gout due to increased uric acid, but also cause cancer.

(Photo source: Visual China)

the truth:

Soybeans are indeed high-purine foods. 100 grams of soybeans contain 218 mg of purine, and 100 grams of black beans contain 170 mg of purine. However, we rarely eat soybeans directly. We usually squeeze them into soy milk, make tofu, dried tofu and other soy products, or cook them. The purine content of soy products in different processing states varies greatly.

After soybeans are processed through grinding, soaking, and diluting with water, the purine content of soy products is significantly reduced. For example, 100 grams of tofu (northern) has only 68 mg of purine, which is a low-purine food. Therefore, except for yuba and bean curd, which are high-purine foods, the purine content of other soy products is not high.

Gout patients should limit their intake of dried soy products with high purine content, but can consume a small amount of soy milk, tofu, and dried tofu of normal concentration without excessive worry. In the acute phase, high-quality protein intake should be mainly eggs and milk, and soy and soy products are not recommended. In other stages, soy products can replace part of the meat and be consumed in moderation.

In addition, soy products contain a substance called isoflavones, which is a type of phytoestrogen found in plants in nature. It is precisely because of this "estrogen" that soy products are blamed for being "carcinogenic". In fact, isoflavones only have weak estrogenic activity. Although it can bind to the estrogen receptors in the human body, its effect is far weaker than the estrogen produced by the human body itself.

In fact, the estrogen-like effect of soy isoflavones can play a bidirectional role in regulating the estrogen level in the body. When the estrogen content in the human body is insufficient, isoflavones combine with estrogen receptors to supplement estrogen; when the estrogen level in the human body is too high, soy isoflavones can prevent estrogen from binding to its receptors and play an inhibitory role, which is equivalent to lowering the estrogen level. For most people, eating soy in moderation may be beneficial in preventing certain types of cancer.

8.The shorter the shelf life of food, the safer it is?

gossip:

The shelf life of food can be long or short. The shorter the shelf life, the fresher and safer it is.

(Photo source: Visual China)

the truth:

This is a misunderstanding. The length of shelf life has no direct relationship with food quality. How long a food can be preserved is closely related to its own properties and production process. In addition, it is also determined by factors such as the food's microbiological, physical, and chemical properties, as well as packaging materials and packaging methods, processing environment conditions, and expected consumption methods.

For example, freshly wrapped rice dumplings need to be eaten as soon as possible, and their shelf life is usually only 3-5 days; the shelf life of vacuum-packed rice dumplings can be extended to 3-6 months, and the shelf life of frozen rice dumplings can reach more than 12 months.

Another widespread misconception is that "food has a long shelf life because a lot of food additives are added". In fact, there is no necessary connection between the length of the shelf life and food additives. Food additives are used to improve or maintain the nutritional value and flavor of the food itself, and to improve the quality and stability of the food. At the same time, it also facilitates the production, processing, packaging, transportation and storage of food. The two basic elements of food additives are safety and necessity. As long as the type and amount are within the legal range, they will not harm the health of consumers.

9.The whiter the teeth, the better?

gossip:

Teeth are originally white, so the whiter the teeth are, the healthier and more beautiful they are.

(Photo source: Visual China)

the truth:

Healthy teeth are not pure white, but natural, shiny, and uniformly yellowish. The color of teeth is mainly determined by the structure of the crown. The outermost layer of the crown is enamel, which is the hardest part of the tooth. The higher the degree of mineralization, the more transparent it is; and the inner layer of enamel is yellowish dentin. Therefore, when the degree of enamel mineralization is high, the yellowish color of dentin will be revealed; when the degree of mineralization is low, the transparency of enamel decreases, and the teeth will appear whiter.

Careful parents will find that their children's teeth become less white after they change from deciduous teeth to permanent teeth. This is because the enamel of permanent teeth is more mineralized than that of deciduous teeth, so the yellowish color of the dentin will be more obvious, making the teeth appear pearly white or yellowish. As we age, teeth will naturally turn yellow due to changes in the composition of enamel, just like a person's skin color and eyeballs. Of course, in real life, in addition to the degree of natural mineralization, there are many external factors that affect the color of teeth, such as smoking, drinking tea, drinking coffee and other habits that cause tooth discoloration, yellowing or staining of teeth. Regular oral examinations and maintaining good oral hygiene habits are necessary to have healthy and beautiful teeth.

10. Does elevated tumor markers mean cancer?

gossip:

Elevated tumor markers indicate cancer.

(Photo source: Visual China)

the truth:

Tumor markers play a very important role in the diagnosis and treatment of tumors, and can be roughly divided into two categories. One category is substances that exist in tumor cells or on the surface of cell membranes, expressed and secreted by tumor cells into the blood, other body fluids and tissues. The other category is substances released by the body in response to tumors.

Tumor marker testing can be used in the following areas: Early warning: Tumor marker testing can show abnormalities in the early stages of a tumor, which can be done before X-rays, ultrasound, CT and other imaging examinations, providing the possibility of early detection of tumors. Auxiliary diagnosis: Tumor marker testing can help doctors determine the presence and type of tumors. Monitoring efficacy: During treatment, tumor marker testing can be used to evaluate the effectiveness of treatment and determine whether the tumor has recurred or metastasized.

Elevated tumor markers do not mean 100% that you have cancer. First, the reference range of tumor markers includes the levels of 95% of healthy people, which means that 5% of healthy people may also have elevated tumor marker test results. Secondly, most classic tumor marker tests use immunological methods, which have non-specific reactions and therefore the possibility of false increases. Finally, although tumor markers are mostly found in malignant tumors, they can also be detected in benign tumors and normal tissues. For example, daily drinking, taking certain medications, and inflammation can all cause a surge in tumor markers.

In summary, if you receive a report showing elevated tumor markers, don’t be too nervous, but you should also take it seriously. The right thing to do is to seek help from a doctor, who will give you a personalized diagnosis and treatment plan based on your medical history, family history, lifestyle, physical examination, and other auxiliary examinations, and through dynamic monitoring of tumor markers.

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 jointly released by the Beijing Science and Technology Journalists and Editors Association and the Beijing Regional Website Joint Rumor-Refuting Platform, and 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 Communication Association, and the Institute of Science and Technology Information of the Beijing Academy of Science and Technology.

Sources of this issue: Beijing Association for Science and Technology, Beijing Science and Technology News, Tencent Jiuzhen, "Science Rumor Refuting" WeChat Official Account, Popular Science Times, Yangtze Evening News, Dingxiang Doctor, "Zhihu Rumor Refuting Frontline" WeChat Official Account